METHOD OF DETERMINING THE VISIBILITY TO A REMOTE DATABASECLIENT OF A PLURALITY OF DATABASE TRANSACTIONS USING SIMPLIFIED VISIBILITY RULES

Abstract: Database management method and system, for a database having a central database (1) and a plurality of partially replicated databases (21-a, 21-b, 21-c). The database management (9) method and system determine the visibility of a user of a separate replicated database to the central database from a set of visibility rules stored at a central location.

Description: METHOD OF DETERMINING THE VISIBILITY TO A REMOTE DATABASECLIENT OF A PLURALITY OF DATABASE TRANSACTIONS USING SIMPLIFIED VISIBILITY RULES INTRODUCTION I.Technical Field This invention relates to a system and method for providing updates to a network of partially replicated relational database systems, and, more particularly, for providing an efficient means for computing the visibility to a client on the network of a transaction processed against the database. II. Background Relational databases are a commonly-employed data structure for representing data in a business or other environment. A relational database represents data in the form of a collection of two-dimensional tables. Each table comprises a series of cells arranged in rows and columns. Typically, a row in a table represents a particular observation. A column represents either a data field or a pointer to a row in another table. For example, a database describing an organizational structure may have one table to describe each position in the organization, and another table to describe each employee in the organization. The employee table may include information specific to the employee, such as name, employee number, age, salary, etc. The position table may include information specific to the position, such as the position title ("salesman", "vice president", etc.), a salary range, and the like. The tables may be related by, for example, providing in each row of the employee table a pointer to a particular row in the position table, coordinated so that, for each row in the employee table, there is a pointer to the particular row in the position table that describes that employee's position. A relational database management system (RDBMS) supports "joining" these tables in response to a query from a user, so that the user making a query about, for example, a particular employee, may be provided with a report of the selected employee, including not only the information in the employee table, but also the information in the related position table. Relational databases may be much more complex than this example, with several tables and a multiplicity of relations among them. With the widespread use of inexpensive portable computers, it is advantageous to replicate a database onto a portable computer for reference at locations remote from the central computer. The replicated database may then be referenced by the user of the portable computer, without requiring reference to the main database, which may be maintained at a central location inconvenient to the user of the portable computer. However, there are a number of difficulties with the use of a replicated database. One disadvantage is that a full copy of the central database may require more data storage than is desired or economical. For example, a salesman working in the field may need to refer to the database for information regarding sales opportunities in his sales area, but have no need to refer to any information regarding sales opportunities outside of his area. One possible approach to reduce the amount of required data storage is to simply replicate only that portion of the database that is needed by the user. However, this approach does not recognize that the criteria to determine which portions of the data are required is likely to vary over time. For example, the salesman may have a new city added to his territory. Under conventional approaches, the salesman would need to re-replicate his local copy of the database, this time selecting data including the added city. Such a practice is inconvenient, subject to error, and time-consuming. A further disadvantage to a replicated database is the difficulties encountered in attempting to update data using the replicated copy. A change made to the replicated database is not made to the central database, leading to a discrepancy between the information that is stored in the replicated copy of the database and the information that is stored in the central database. Although it is possible to journal modifications made to the replicated copy and apply an identical modification to the central database, one problem that this approach faces is the possibility of colliding updates; that is, where a user of a replicated copy makes a change to data that is also changed by a user of the central copy or by the user of another replicated copy. It is therefore desirable to provide a capability to maintain one or more partially-replicated copies of a central database, in such a way that the degree of replication may be easily changed without requiring a refresh of the entire replicated database, and that permits updates to be coordinated among users of the central database and users of the partially replicated databases. SUMMARY OF THE INVENTION The present invention is directed to a method of maintaining a partially replicated database in such a way that updates made to a central database, or to another partially replicated database, are selectively propagated to the partially replicated database. Updates are propagated to a partially replicated database if the owner of the partially replicated database is deemed to have visibility to the data being updated. Visibility is determined by use of predetermined rules stored in a rules database. In one aspect of the invention, the stored rules are assessed against data content of various tables that make up a logical entity, known as a docking object, that is being updated. In another aspect of the invention, the stored rules are assessed against data content of one or more docking objects that are not necessarily updated, but that are related to a docking object being updated. In one embodiment, the visibility attributes of the related docking objects are recursively determined. In yet another aspect of the invention, changes in visibility are determined to enable the central computer to direct the nodes to insert the docking object into its partially replicated database. Such changes in visibility are determined so as to enable the central computer to direct a node to remove a docking object from its partially replicated database. In a further aspect of the invention, the predetermined rules are in declarative form and specify visibility of data based upon structure of the data without reference to data content. In still another aspect of the invention, the transactions made to the database are ordered and processed in such a way as to reduce the computational resources required to calculate the visibility of the transactions. In still another aspect of the invention, the transactions made to the database are ordered and processed using a cache in such a way as to reduce the computational resources required to calculate the visibility of the transactions. In still another aspect of the invention, database objects and transactions have an associated visibility strength used to determine the visibility of a transaction to an object. In still another aspect of the invention, the visibility calculations are performed using a simplified set of rules located in a central dictionary. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 depicts an overview of the operation of one embodiment of the present invention. Figure 2 depicts a database schema that shows the relationship of the various components that make up a Docking Object. Figure 3 depicts steps performed by an update manager to update a database. Figure 4 depicts steps performed by a Docking Manager to transmit and/or receive one or more transaction logs. Figure 5 depicts the steps performed by a merge processor to merge transaction log records into an existing database. Figure 6 depicts the steps performed by a log manager to prepare a partial transaction log. Figure 7 depicts the steps performed by a visibility calculator for calculating visibility for a docking object as invoked by a log manager. Figure 8 depicts the steps performed to synchronize a partially replicated database in response to a change in data visibility. Figure 9 depicts the structure of the database design of the transaction log table. Figure 10 depicts a database diagram for the central dictionary. DESCRIPTION OF SPECIFIC EMBODIMENTS Overview Figure 1 depicts an overview of the operation of one embodiment of the present invention. Figure 1 depicts a central computer system 1 and three remote computer systems (or "nodes") 21-a, 21-b, and 21-c. Each of nodes 21-a, 21-b and 21-c are depicted in various states of communication with central computer system 1, as will be more fully explained. Central computer system 1 includes a central database 3, a docking manager 5, a merge processor 7 and a log manager 9. Central computer system 1 additionally optionally includes update manager 11 responsive to user input 13. Node 21-a is a remote computer system, such as a mobile client such as a laptop computer. Node 21-a includes a partially replicated remote database 23-a, update manager 31-a responsive to user input 33-a, docking manager 25-a and merge manager 27-a. In operation, update manager is responsive to user input 33-a to make changes to remote database 23-a as directed by the operator of node 21-a. Updates made are recorded, or journaled, in node update log 35-a. At some point at the convenience of the operator of node 21-a, node docking manager 35-a is activated, and enters into communication with central docking manager 5. Update log 35-a is taken as input by node docking manager 25-a, and provided to central docking manager 5. Central docking manager 5 creates a received node update log 19, which contains all the information that had been recorded in update log 35-a. Optionally, partial log 17-a is taken as input by central docking manager 5 and provided to node docking manager 25-a, as more fully described herein. At some point in time, at the convenience of the operator of central computer system 1, merge processor 7 is activated. Merge processor 7 takes as input received node update log 19, and applies the updates described therein to central database 3. In the process of applying the updates from received node update log 19, merge processor journals the updates applied to central update log 15. Optionally, update manager 11, responsive to user input 12 makes additional changed to central database 3 as directed by the operator of central computer system 1. The updates made by update manager 11 are additionally journaled in central update log 15. At some point in time, at the convenience of the operator of central computer system 1, log manager 9 is activated. Log manager 9 takes as input central update log 15 and produces as output a set of partial logs 17-a, 17-b and 17-c according to visibility rules as will be further described herein. Each of partial logs 17-a, 17-b and 17-c corresponds to one of nodes 21-a, 21-b and 21-c. When a node docking manager such as node docking manager 25-a enters into communication with central docking manager 5 and optionally requests transmission of its corresponding partial log, central docking manager 5 takes as input the appropriate partial log, such as partial log 17-a, and presents it to node docking manager 25-a. Node docking manager 25-a then replicates partial log 17-a as merge log 37-a. At some point in the future, at the convenience of the operator of node 21-a, merge processor 27-a is activated. Merge processor 27-a takes as input merge log 37-a, and applies the updates described therein to partially replicated database 23-a. In addition to node 21-a, Figure 1 also depicts two additional nodes 21-b and 21-c. Node 21-b is depicted in communication with central computer 1. However, unlike node 21-a, the operator of node 21-b has requested only to send his updates to central computer system 1, and has not requested to be presented with changes made elsewhere to be made to his partially replicated database 23-b. This may be, for example, if the operator has an urgent update that must be made as soon as possible, but does not have the time to receive updates from other nodes. Accordingly, Figure 1 shows only transmission of node update log 35-a from node docking manager 25-b to central docking manager 5, and no transmission from central docking manager 5 to node docking manager 25-b. Accordingly, the merge manager for node 21-b is not activated and is not shown. Likewise, node 21-c is depicted as not in communication with central computer system 1. Accordingly, the docking manager for node 21-c is not activated and is not shown. By the cycle described above, updates made by each of nodes 21-a, 21-b and 21-c are presented to central computer system 1, permitting central database 3 to be updated accordingly. In addition, each of the updates made by each of the nodes 21a, 21-b and 21-c, as well as updates made on central computer system 1, are routed back to each of nodes 21-a, 21-b, and 21-c, thereby keeping each of partial databases 23-a, 23-b and 23-c in synchronization with each other and with central database 3. Database Structure The synchronization of central database 3 with node databases 23-a, 23-b and 23-c is performed using a construct called a Docking Object. A Docking Object consists of Member Tables (including one Primary Table), Visibility Rules, Visibility Events, and related Docking Objects. Each docking object has a visibility level and visibility lead attributes as will be described more fully herein below. A Member Table is a table of the relational database that makes up a docking object. When a docking object is propagated from central database 3 to one of node databases 23-a, 23-b or 23-c, the propagation takes the form of an insertion into each of the Member Tables associated with the particular docking object. Similarly, when a docking object is scheduled to be removed from a database, that removal consists of deleting records from the member tables associated with the docking object. For example, a docking object that represents a sales opportunity may include tables that represent the opportunity itself (e.g., named "S¯OPTY"), the product whose sale is represented by the opportunity (e.g., named "S OPTY PROD"), the contact for the opportunity (e.g., named "S OPTY CONTACT"), etc. Each of these tables is said to be a member table of the "Opportunity Docking Object." In an additional aspect of the invention, each member table row can have one or more rows that correspond to the docking object. A Primary Table is a Member Table that controls whether a particular instance of a Docking Object is visible to a particular node. The Primary Table has a Primary Row-ID value that is used to identify a row of the Primary Table being updated, deleted or inserted. For example, the "Opportunity Docking Object" may have as a primary table the table S OPTY. The row-id of that table, i.e., S OPTY.row id, is the Primary Row-ID for the Opportunity Docking Object. Each dock object has a visibility level and a visibility level attribute that are analyzed using visibility rules. The valid values are 'Enterprise', 'Limited' and 'Private.' all member table rows in an enterprise dock object are replicated to any nodes. Member table rows in limited dock objects are replicated to any nodes. Member table rows in limited dock objects are subject to visibility checks and are routed to nodes that have visibility to the rows. A Visibility Rule is a criterion that determines whether a particular instance of a Docking Object is "visible" to a particular node 21. If a Docking Object is visible to a particular node, that node will receive updates for data in the Docking Object. Visibility Rules are of two types, depending on the field RULE¯TYPE. A Visibility Rule with a RULE¯TYPE of "R" is referred to as an SQL Rule. An SQL Rule includes a set of Structured Query Language (SQL) statements that is evaluated to determine if any data meeting the criteria specified in the SQL statements exists in the Docking Object. If so, the Docking Object is visible to the node. A Visibility Rule with a RULE¯TYPE of "O" is referred to as a Docking Object Rule. A Docking Object Rule specifies another Docking Object to be queried for visibility. If the specified Docking Object is visible, then the Docking Object pointing to it is also visible. A Related Docking Object is a Docking Object that is propagated or deleted when the Docking Object under consideration is propagated or deleted. For example, an Opportunity Docking Object may have related Docking Objects representing the sales contacts, the organizations, the products to be sold, and the activities needed to pursue the opportunity. When an Opportunity Docking Object is propagated from Central Database 3 to one of node databases 23, the related docking objects are also propagated. Figure 2 depicts a database schema that shows the relationship of the various components that make up a Docking Object. The schema is a meta-database, in that it does not describe the data being accessed in the database. Rather, the schema is a separate database that defines the structure of the database being accessed. That is, it is a database comprising tables that describe the relationships and data contexts of another database. Each of the tables shown in Figure 2 is a table in a relational database, and as such is in row-column form. Many columns represent fields that are common to all the illustrated tables. Such fields include for example, a ROW¯ID to identify a particular row in the table, as well as fields to track the date and time that a row was created and last modified, and the identity of the user who created or modified the row. In addition, each table contains fields specific to that table, and which are described in detail below. Table S¯DOBJ 61 describes the Docking Objects in an application. Table S¯DOBJ 61 includes the fields OBJ¯NAME and PRIMARY¯TABLE¯ID. Field OBJ¯NAME defines the name of the Docking Object being described. Field PRIMARY¯TABLE¯ID is used to identify the primary table associated with this Docking Object. Table S¯DOBJ¯INST 63 describes whether a particular instance of a Docking Object, described by table S DOBJ 61, is present on a particular node's database. Table S¯DOBJ¯INST 63 includes the fields NODE¯ID, DOBJ¯ID and PR¯TBL¯ROW¯ID. Field NODE¯ID points to a particular node table 65. Field DOBJ¯ID points to the Docking Object to which the Docking Object instance applies. Field PR¯TBL¯ROW¯ID is used to select a particular row in the Primary Table of the Docking Object. This value identifies the Docking Object instance. Table S¯REL¯DOBJ 67 describes the related Docking Objects of a particular Docking Object, described by table S¯DOBJ 61. Table S¯REL¯DOBJ 67 includes the fields DOBJ ID, REL¯DOBJ¯ID, and SQL¯STATEMENT. Field DOBJ¯ID identifies the Docking Object that owns a particular related Docking Object. Field REL¯DOBJ¯ID identifies the related Docking Object that is owned by the Docking Object identified by DOBJ¯ID. Field SQL STATEMENT is an SQL statement that may be executed to obtain the Primary ID value of the related Docking Object. Table S¯DOBJ¯TBL 69 describes the member tables of a particular Docking Object, described by table S¯DOBJ 61. Table S¯DOBJ¯TBL 69 includes the fields DOBJ¯ID, TBL ID, and VIS¯EVENT¯FLG. Field DOBJ¯ID identifies the Docking Object that contains the member table described by the row. Field TBL¯ID identifies the particular table in the database that is the member table described by the row. Field VIS¯EVENT¯FLG is a flag that indicates whether a change to this Docking Object can result in a visibility event. A value of "Y" indicates that a change can result in a visibility event; a value of "N" indicates that it cannot. Table S¯DOBJ¯VIS¯RULE 71 contains the visibility rules associated with a particular Docking Object. S¯DOBJ¯VIS¯RULE 71 contains the fields DOBJ¯ID, RULE¯SEQUENCE, RULE¯TYPE, SQL¯STATEMENT and CHECK¯DOBJ¯ID. Field DOBJ¯ID identifies the Docking Object with which a particular visibility rule is associated. Field RULE SEQUENCE is a sequence number that indicates the sequence, relative to other visibility rules in table S¯DOBJ¯VIS¯RULE 71, in which the particular visibility rule should be run. RULE¯TYPE specifies whether the particular visibility rule is of type "R," indicating an SQL visibility rule or of type "0," indicating a Docking Object visibility rule. If RULE¯TYPE is equal to "R," field CHECK¯DOBJ¯ID is not meaningful, and field SQL¯STATEMENT contains an SQL statement that is evaluated using the Primary ROW-ID of the primary table associated with this Docking Object and a particular Node 21. If the SQL statement returns any records, the Docking Object is deemed to be visible to the Node 21 for which visibility is being determined. If RULE¯TYPE is equal to "0," both field CHECK¯DOBJ¯ID and field SQL STATEMENT are meaningful. Field CHECK DOBJ ID specifies a docking object whose visibility should be determined. If the specified docking object is deemed to be visible, then the docking object associated with the visibility rule is also visible. Field SQL¯STATEMENT contains a SQL statement that, when executed, returns the Row-ID of the docking object identified by CHECK¯DOBJ¯ID that corresponds to the docking object instance associated with the visibility rule. Table S¯APP¯TBL 73 is an Application Table that describes all the tables used in a particular application. It is pointed to by table S DOBJ TBL 69 for each member table in a docking object, and by table S¯DOBJ for the primary table in a docking object. S¯APP¯TBL 73 points to table S¯APP¯COL 75, which is an Application Column Table that describes the columns of data in a particular application. S¯APP¯TBL 73 points to table S¯APP¯COL 75 directly through a primary key and indirectly through such means as a Foreign Key Column Table 81, User Key Column Table 83, and Column Group Table 85. The relationship of an Application Table, Application Column Table, Foreign Key Column Table, User Key Column Table and Column Group Table are well known in the art and are not further described. Update Processing Figure 3 depicts steps performed by an update manager 31 such as update manager 31-a, 31-b or 31-c in updating a database, such as a node database 23-a, 23b or 23-c, responsive to user input. Execution of update manager 31 begins in step 101. In step 103, the update manager 31 accepts from the user input 33 in the form of a command requesting that the data in database 23 be altered. The request may be in the form of a request to delete a row of a table, to add a row to a table, or to change the value of a cell at a particular column of a particular row in a table. In step 105, using a well-known means, the update manager 31 applies the requested update to database 23. In step 107, the update manager 31 creates a log record describing the update and writes it to update log 35. The contents of a log record describe the update made. Each log record indicates the node identifier of the node making the update, an identification of the table being updated, and an identification of the type of update being made, i.e., an insertion of a new row, a deletion of an existing row, or an update to an existing row. For an insertion, the log record additionally includes an identifier of the row being inserted, including its primary key and the values of the other columns in the row. For a deletion, the log record identifies the primary key of the row being deleted. For an update, the log record identifies the primary key of the row being updated, the column within the row being updated, the old value of the cell at the addressed row and column, and the new value of the cell. After writing a log record in step 107, the update processor exits for this update. The foregoing description of the update processing preferably includes additional steps not material to the present invention, for example, to assure authorization of the user to make the update, to stage and commit the write to the database to allow for rollback in the event of software or hardware failure, and the like. These steps are well-known in the art and are not described further. An update manager 11 executing in central computer system 1 operates in an analogous manner, except that it updates central database 3 and writes its log records to central update log 11. Docking Processing Figure 4 depicts steps performed by a Docking Manager 25 such as Docking Manager 25-a, 25-b or 25-c to transmit and/or receive one or more transaction logs. Docking Manager 25 is invoked by the user of a remote node such as node 21-a, 21-b or 21-c, whereby the user requests that the node dock with central computer 1 to upload an update log such as update log 35-a to central computer 1, to download a partial log such as partial log 17-a, or both. Execution of Docking Manager 25 begins in step 121. In step 123, Docking Manager 25 connects with central computer 1 under the control of Central Docking Manager 5. This connection can be any connection that enables data exchange. It is anticipated that the most common form of a connection is a telephone line used in conjunction with a modem, but other forms of data connection, such as a Local Area Network or a TCP/IP connection may also be used. Step 125 checks to see whether the user has requested that node update log 35-a be uploaded to the Central Computer 1. If so, execution proceeds to step 127. If not, step 127 is skipped and control is given to step 129. In step 127, Docking Manager 25 uploads its update log to central computer 1. The upload may be accomplished with any known file transfer means, such as XMODEM, ZMODEM, KERMIT, FTP, ASCII transfer, or any other method of transmitting data. In step 129, Docking Manager 25 checks to see whether the user has requested that a partial log such as partial log 17-a be downloaded from Central Computer 1. If so, execution proceeds to step 131. If not, step 131 is skipped and control is given to step 133. In step 131, Docking Manager 25 downloads its partial log from central computer 1. The download may be accomplished with any known file transfer means, such as XMODEM, ZMODEM, KERMIT, FTP, ASCII transfer, or any other method of transmitting data. In step 133, having completed the requested data transfer, Docking Manager 25 exits. Merge Processing Merge processing is performed by a processor such as node merge processor 27-a, 27-b, or 27-c, or central merge processor 7. The merge process serves to update its associated database with a transaction that has been entered by a user of a computer remote from the computer where merge processing is being performed. Merge processing is analogous to update processing and is similar in form to update processing as previously disclosed with reference to figure 3, with three differences. First, the input to a merge processor is not an update entered directly by a user, but rather is a log file that is obtained from a computer remote from the computer where the merge is executing. A second difference is that, as shown by in Figure 1, merge processing does not produce a log when performed at a node. The function of a log on a node is to record a transaction for propagation to Central Computer system 1 and thence to other nodes as required. A transaction that is the subject of a merge in a node has been communicated to Central Computer System 1, and there is no need to re-communicate it. A third difference is that merge processing must be capable of detecting and resolving multiple conflicting transactions. For example, assume that a field contains the value "Keith Palmer." Assume further that a user at node 27-a enters a transaction to update that field to "Carl Lake," and a user at node 27-b enters a transaction to update the same field to "Greg Emerson." Without collision detection, data among various nodes may become corrupt. When the transaction for user 27-a is merged, the field is updated from "Keith Palmer" to "Carl Lake." Without collision handling, when the transaction for node 27-b is merged, the field would be updated to "Greg Emerson," and the central database would then be out of synch with the database of node 27-a. Furthermore, when merge processing is performed on each of nodes 27-a and 27-b, each node will update its database with the other's transactions, leaving at least one node out of synch with the other node and with central database. Therefore, merge processing must also have a means of detecting collisions and correcting them. In the above example, a simple way to detect and correct a collision is to compare the value in the database to the value that the merge log reflects as being the previous value in the node database. If the two values do not match, Merge processor 7 may reject the transaction and generate a corrective transaction to be sent to the node from which the conflicting transaction originated. In the above example, when the transaction for node 27-b was presented to merge processor 7, merge processor 7 would compare "Keith Palmer," the prior value of the field as recorded by node 27-b to "Carl Lake," the present value of the field as recorded in central database 3. Detecting the mismatch, merge processor 7 may then generate a transaction to change the value "Greg Emerson" to "Carl Lake, " and write that transaction to update log 15. The above is one example of a collision and a resulting corrective action. Other types of collisions include, for example, an update to a row that has previously been deleted, inserting a row that has previously been inserted, and the like. Merge processing must detect and correct each of these collisions. This may be performed using any of a number of well-known methods, and is not discussed further. Figure 5 depicts the steps performed by merge processor such as central merge processor 7. Although it depicts merge processor 7 writing to central database 3 and to transaction log 15, it is equally representative of a node merge processor such as node merge processor 27-a, 27-b or 27-c updating a node database 23-a, 23-b or 23c. Merge processing begins at step 141. In step 143, merge processor 7 finds the first unprocessed transaction on received log 19. In step 147, merge processor 7 selects a transaction from received log 19. In step 149, merge processor 149 attempts to update database 3 according to the transaction selected in step 147. In step 151, merge processor 7 determines whether the database update of step 149 failed due to a collision. If so, merge processor proceeds to step 153, which generates a corrective transaction. Following the generation of the corrective transaction, the merge processor returns to step 149 and again attempts to update database 3. If no collision was detected in step 151, execution proceeds to step 157. In step 157, merge processing checks to see if it is executing on central computer 1. If so, step 155 is executed to journal the transaction to log 15. In any case, either if step 157 determines that the merge processing is being performed on a node or after step 155, execution proceeds to step 159. Step 159 checks to see if any transactions remain to be processed from log 19. If so, execution repeats from step 147, where the next transaction is selected. If not, merge processing exits in step 161. Log Management Figure 6 depicts the steps to be performed by log manager 9 to prepare a partial transaction log such as partial transaction log 17-a, 17-b, or 17-c. The procedure depicted in Figure 6 is executed for each node available to dock with central computer system 1. Log manager 9 begins execution in step 171. In step 173, Log Manager 9 finds the first unprocessed transaction for the node whose partial transaction log is being prepared. In step 175, log manager 9 selects a transaction for processing. In step 177, log manager 9 checks to see whether the selected transaction originated on the same node for which processing is being performed. If so, there is no need to route the transaction back to the node, and control proceeds to step 179. Step 179 checks to see whether there are any transactions remaining to be processed. If so, control is given again to step 175. If not, control passes to step 189, which records the last transaction that was processed for this node, and then exits at step 191. If the transaction originates in other than the same node as the node for which processing is being performed, control is given to step 181. Step 181 calls a visibility calculator to determine whether the selected transaction is visible to the node being processed. The Visibility calculator routine is described in detail further herein. In step 183, log manager 9 checks to see whether the visibility calculator determined that the transaction is visible. If it is not visible, control is passed to step 179, which performs as disclosed above. If the transaction is visible, control is passed to step 185. Step 185 writes a record for this transaction to the partial transaction log for the node being processed, for example, partial transaction log 17-a for node 21-a. In step 187, the log manager 9 records the last transaction that was processed for this node, and then passes control to step 179, which determines whether to select additional transactions or exit, as disclosed above. Visibility Calculation Figure 7 depicts a flowchart describing the process a visibility calculator for calculating visibility for a docking object as invoked by step 181 of log manager 9. The visibility calculator is called with the node-id of the node for which visibility is being calculated, the docking object for which the visibility is being calculated, and the row-id of the docking object whose visibility id being calculated. The visibility calculator uses this information, in conjunction with information obtained from metadata stored in the schema depicted in Figure 2, to determine whether a particular transaction that updates a particular row of a particular docking object is visible to a particular node. The Visibility calculator begins execution at step 201. In step 203, the visibility calculator makes a default finding that the transaction is not visible. Therefore, unless the visibility calculator determines that a transaction is visible, it will exit with a finding of no visibility. In step 205, the visibility calculator selects the first visibility rule associated with the docking object. This is done by finding the table S DOBJ VIS RULE 71 associated with the current Docking Object as pointed to by table S¯DOBJ 61. In step 205, the visibility calculator selects the row of table S DOBJ VIS RULE 71 with the lowest value for field RULE SEQUENCE. In step 207, the Visibility Calculator checks the field RULE TYPE for a value of "R. " The value of "R" indicates that the rule is a SQL visibility rule. If so, the Visibility Calculator proceeds to step 209. In step 209 the Visibility Calculator obtains a SQL statement from field SQL STATEMENT and executes it. An example of such an SQL statement might be: SELECT 'X' FROM S¯OPTY¯EMP WHERE OPTY¯ID = :PrimaryRowId AND EMP¯ID = Node; This SQL statement causes a query to be made of application table S¯OPTY¯EMP. The query selects any records meeting two criteria. First, the records selected must have a field OPTY¯ID, which is a row id or key, equal to the Primary Row-ID of the Docking Object whose visibility is being determined. Second, the records selected must have a field EMP ID, which may be for example, an identifier of a particular employee, equal to the NodeId of the node for whom visibility is being determined. In ordinary language, this SQL statement will return records only if a row is found in a table that matches employees to opportunities, where the opportunity is equal to the one being updated, and the employee to whom the opportunity is assigned is the operator of the node. This is a simplistic example, provided for maximum comprehension. More complex SQL statements are possible. For example, the rule: SELECT 'X' FROM & Table Owner.S ACCT POSTN ap & Table Owner.S¯EMP POSTN ep WHERE ap.POSITIONID = ep.POSITION ID AND ep.EMP¯ID = :NodeId; This rule queries the tables S¯ACCT¯POSTN (which relates a particular account with a particular position in the organization that is responsible for the account) and S EMP POSTN (which relates what employee corresponds to a particular position). The condition "ap.POSITION = ep.POSITION¯ID" requires finding a row in the account-to-position table that has the same position as a row in the employee-to-position table. The condition "ep.EMP ID = :NodeId" further requires that the selected row in the employee-to-position table also have an Employee ID equal to the ID of the user of the Node for which visibility is being determined. In ordinary language, this condition allows visibility if the employee occupies the position that has responsibility for the account in the docking object being updated. There is no particular limit to the complexity of the conditions in the SQL statement used to evaluate visibility. Particular implementations of SQL may impose limitations, and resource considerations may make it desirable to use less complex statements, but these limitations are not inherent in the invention. Step 211 evaluates whether the execution of SQL STATEMENT in step 209 returned any records. If records were returned, this indicates that the Node for which visibility is being checked has visibility to the docking object being processed. Accordingly, if records are returned, the Visibility Calculator proceeds to step 213. In step 213, the transaction is marked visible. Because no further rules need to be evaluated to determine visibility, the visibility calculator proceeds to step 228. Step 228 synchronizes the databases by determining whether the calculated visibility requires the insertion or deletion of a docking object into a particular node's partially replicated database. This may occur, for example, if a node is determined to have visibility to a docking object due to a change to a related docking object. For example, an owner of a node may be assigned to a particular activity that is related to a particular sales opportunity. As a result, the node should be provided with a copy of the object representing the sales opportunity. Figure 8 depicts the steps performed to synchronize a partially replicated database in response to a change in data visibility. Execution begins in step 241. In step 243, the Visibility Calculator references the visibility just calculated for a docking object. If the Docking Object is visible, execution proceeds to step 245. Step 245 references the S DOBJ INST table, to verify that a row exists for the Docking Object for the current node. If a row exists, this indicates that the node in question already has a copy of the referenced Docking Object, and the routine proceeds to step 255, where it exits. If, however, no row exists for the Docking Object at the node being processes, this indicates that the node in question does not have a copy of the Docking Object on its partially replicated database. The routine then proceeds to step 247, where a transaction is generated to direct the node to insert the Docking Object into its partially replicated database. If step 243 determines that the Docking Object is not visible, execution proceeds to step 249. Step 249 references the S DOBJ INST table, to verify that no row exists for the Docking Object for the current node. If step 243 determines that no row exists in the S DOBJ¯INST table for the current docking object for the current row, this indicates that the node in question does not have a copy of the referenced Docking Object, and the routine proceeds to step 255, where it exits. If, however, a row exists for the Docking Object at the node being processed, this indicates that the node in question does have a copy of the Docking Object on its partially replicated database. The routine then proceeds to step 251, where a transaction is generated to direct the node to delete the Docking Object from its partially replicated database. Referring again to Figure 7, following the data synchronization routine of step 228, the Visibility Calculator proceeds to step 229, where it exits. Referring to Figure 6, as previously described, the resulting finding of visibility is available to be checked by the log manager in step 183 to determine to write the transaction. Referring again to figure 7, if step 211 determines that no records were returned by the execution of the SQL statement in step 209, execution proceeds with step 215. Step 215 checks to see whether there are any remaining visibility rules to be assessed. If not, the visibility calculator proceeds to step 228 to synchronize the database, and then to step 229, where it exits. In this case, the default mark of no visibility that was set in step 203 remains set. This value will also be used by the log manager as shown in Figure 6, step 183, to determine not to write the transaction. Referring again to Figure 7, if rules remain to be assessed, control proceeds to step 217, which selects the next rule to be processed. Control is then given again to step 207 to begin processing the new rule. The preceding text provided a description of the processing or SQL visibility rule; that is, visibility rules of type "R." If step 207 determines that the visibility rule is not of type "R," the visibility rule is of type "0." Type "0" indicates a dockingobject visibility rule. In such a case, the docking object being processed will be considered to be visible if it is related to a particular related docking object that is visible. If field RULE TYPE is not equal to "R,"then. execution proceeds to step 221. Step 221 determines the related Docking Object whose visibility must be determined to determine whether the current docking object is visible. The related Docking Object identifier is obtained from field CHECK¯DOBJ¯ID in table S DOBJ VIS¯RULE 71. In step 223, the Visibility Calculator determines which row in the related Docking Object must be queried for visibility. In order to determine this, the Visibility Calculator obtains a predetermined SQL statement from the field SQL STATEMENT and executes it. The SQL statement is a query that select one or more rows of the Docking Object that, for example, correspond to the docking object for which the Visibility Calculator was invoked. For example, assume that it is desired to indicate that a record for a sales opportunity should be visible if the Node has visibility to any sales quote made for that sales opportunity. This may be accomplished using the following SQL statement: SELECT "ROW¯ID" FROM & Table Owner.S DOC QUOTE WHERE OPTY¯ID=:Primary Rowld This SQL statement accesses a table S DOC QUOTE that contains all sales quotes. The WHERE clause specifies retrieval of all rows where the Opportunity ID of the row is equal to the Row-ID of the opportunity for which visibility is being calculated. The Visibility manager retrieves the specified Row-Ids, thereby identifying the rows of the S¯DOC¯QUOTE table whose visibility must checked. Having determined the a related docking object and the row-ID of that related docking object upon whose visibility the visibility of the current docking object depends, the Visibility Calculator proceeds to step 225. In step 225, the Visibility Calculator recursively invokes itself to determine visibility of the related docking object. The recursively invoked Visibility Calculator operates in the same manner as the Visibility Calculator as called from the Log Manager 9, including the capability to further recursively invoke itself. When the recursive call concludes, it returns a visibility indicator for the related Docking Object, and control proceeds to step 227. In step 227, the Visibility calculator determines whether the related Docking Object was determined to have been visible. If so, the Visibility Calculator proceeds to step 213 to mark the originally current Docking Object as visible, and then to step 228 to synchronize the database and then to step 229 to exit. If the related Docking Object was not determined to be visible, control proceeds to step 215 to determine whether additional visibility rules remain to be assessed. The Visibility Calculator, in conjunction with the Log Manager is therefore able to determine what subset of update transaction data is required to be routed to any particular node. This operation serves to reduce the transmission of unneeded data from the Central Computer 1 to the various nodes such as nodes 21-a, 21-b and 21-c that utilize partially replicated databases, and to reduce the system resources such as disk space needed to store, and the CPU time needed to process, what would otherwise be required to maintain a fully replicated database on each remote node. The operation of the log manager 9 in conjunction with the Visibility Calculator herein described will be apparent from reference to the description and to the drawings. However, as a further aid in the description of these facilities, a pseudocode representation of these facilities is hereto attached as an Appendix. Batch Visibility Calculation The calculation of visibility events and the routing of visible transactions may be optimized by batching related SQL statements, rather than performing successive row-by-row operations. This optimization is achieved by eliminating redundant operations, using set processing and reducing network traffic. Redundant work is eliminated by denormalizing key data used to calculate visibility into the transaction log. For example, the Log Manager the docking object, primary table id, visibility event flags, and related data are stored in the transaction log table. Instead of calculating this data once for every mobile client, Log Manager calculates this data once for all mobile clients to use. Log Manager uses set processing by submitting SQL statements to check the visibility of many thousands of transactions simultaneously instead of submitting a SQL statement for each transaction. Network traffic is reduced by retrieving only the visible transactions from the database server to the docking server. Consequently, significantly less data travels over the network from the database server to the docking server. Figure 9 depicts the structure of the database design of the Transaction Log Table 300 used to support batch visibility checking. Node table 301 is the central table of the database, and contains one-to-many pointers to Dock Object Instance table 302, Dock Status table 304, and Transaction table 306. Docking Object Instance table 302 stores whether a docking object instance is visible to a mobile client and has been downloaded to the mobile client. A row exists in Docking Object Instance table 302 if the docking object instance is fully visible or partially visible to the mobile client. If the docking object is not visible, then a row for the docking object instance does not appear in Docking Object Instance table 302. Docking Object Instance table 302 (S DOBJ INST) comprises the following fields to support batch visibility checking: NODE ID: a non-null user key of the node to which this docking object instance relates. DOBJ¯ID: a non-null user key of the docking object to which this docking object instance relates. PR TBL¯ROW ID: a non-null user key containing the Row¯ID of the primary table in the docking object. This value identifies the Docking Object Instance. STAT Flag: a one-byte flag containing the value 'F' or 'P'. The value 'F' indicates that the docking object instance is fully visible. The value 'P' indicates that the docking object instance is partially visible. LAST CHK ?XN ID: the transaction ID of the transaction in which the visibility of the dock object instance was last checked. This value may be used to determine when the dock object instance must be recalculated. For example, if LAST¯CHK¯TXN¯ID = 3000, then Log Manager should not re calculate visibility of the dock object instance until a visibility event occurs after transaction ID 3000. Dock Status table 304 stores status information relating to each mobile client. This includes the identity of the last file merged, the last file extracted, and the last transaction extracted. Dock Status Table 304 (S DCK STAT) comprises the following fields to support batch visibility checking: ROW ID: primary key. NODE¯ID: Identity of the mobile client that owns this status information. TYPE: This field is used to interpret the VAL field, and contains one of the strings "EXTRACT¯RECORD", "LOG EXTRACT", "MERGE RECORD", "LAST¯MERGE", or "SESSION". VAL: This field contains the value corresponding to the data type in the TYPE field. In addition, this table records the last transaction processed byan executable program called the Log Preprocessor. This is indicated in the VAL field for a row with a ROW¯ID of zero and a TYPE of "EXTRACT¯RECORD". Transaction table 306 stores transaction that may need to be routed to all mobile clients. Transaction table 306 (S¯DCK¯TXN¯LOG) comprises the following fields to support batch visibility checking: TXN¯ID: A non-null primary key that identifies the transaction. DOBJ¯ID: a non-null user key of the docking object to which this docking object instance relates. PR¯TBL¯ROW¯ID: a non-null user key containing the Row¯ID of the primary table in the docking object. This value identifies the Docking Object Instance. VIS¯EVT¯FLG: This field contains either the value 'Y' or 'N', and indicates whether the transaction causes a visibility event. VIS¯LEVEL¯FLG: This field indicates the visibility level of the dock object. A value 'L' indicates that the dock object has limited visibility. A value of 'P' indicates that the dock object is private. A value of 'E' indicates that this object has enterprise visibility. Batch visibility checking executes in four phases. Briefly, Phase 1 is run one for each transaction in Transaction Log Table 300 and denormalizes the transaction log data into the constituent tables. Phase 2 is run once per mobile client per iteration, and checks for visibility events for a mobile client. Phase 3 is run once per mobile client per iteration, and extracts visible transactions for the mobile client. Phase 4 is run once per iteration and deletes transactions from Transaction Log Table 300. Details of all four phases are described below. In an embodiment of the present invention, phases 1 and 4 may be combined into a single executable program called the Log Preprocessor. Only one Log Preprocessor is run against an installation at any one time. Phases 2 and 3 may be combined into a single executable program called the Log Router. One or more Log Routers may be run against a single installation concurrently. The Log Router program may use semaphores to prevent more than one Log Router from routing transactions to the same mobile client simultaneously. Phase 1 is run one for each transaction in Transaction Log Table 300 and denormalizes the transaction log data into the constituent tables. This phase denormalizes values in S¯DCK¯TXN¯LOG based on transaction log data. The following pseudocode describes the operation of Phase 1 in detail: DoPhasel () -- Get status values so we can identify which txns to pre-process Get max(TXN ID) from S¯DCK¯TXN¯LOG Get TXN PROCESSED ID from DUCK START for Node id O numTxns := 0; -- SELECT ti.* -- FROM S¯DCK¯TXN¯LOG tl -- WHERE TXN ID > max(TXN?ROCESSED¯ID) -- AND TXN ID < = max(TXNiD) -- ORDER BY TXN ID ASC FOR each txn between max(TXN ID) and TXN¯PROCESSED¯ID LOOP -- If the client program already calculated the denormalized -- columns, then we don't have to do it again. IF tl.DOBJ¯ID is not null THEN continue; END IF; FOR each operation in the txn LOOP -- Use UTLIdSql() to get primary table row¯ids -- Assumes that each txn can only have one primary row¯id FOR each primary id row LOOP IF operation is a visibility event THEN p¯vis¯evt¯fig : = 'Y'; ELSE p¯vis¯evt¯fig : = 'N'; END IF; update S¯DCK¯TXN¯LOG set (DOBJ¯ID, PR¯TBL¯ROW¯ID, VIS¯EVT¯FLG) = (DOBJ¯ID, PR¯TBL¯ROW¯ID, p¯vis¯evt¯flg) where TXN ID = current txn¯id; END IF; END LOOP; -- each operation numTxns := numTxns + 1; END LOOP; -- each txn -- Commit after every N txns IF numTxns > maxTxns THEN Set TXN¯PROCESSED¯ID = current TXN¯ID commit; numTxns:= 0; -- lock the row again Get TXN¯PROCESSED¯ID from S¯DCK¯STAT for Node id 0 END IF; END LOOP; -- for loop Phase 2 is run once per mobile client per iteration, and checks for visibility events for a mobile client. This phase looks for all visibility event transactions and recomputes visibility. The phase downloads and removes Docking Obect instances in response to visibility changes and stores the visibility of Docking Object instances.in table S¯DOBJ¯INST 63. The following pseudocode describes the operation of Phase 2 in detail: ProcessVisibilityEvent (DOBJ¯ID, PR TBL ROW ID, STAT¯FLG) -- If we have already calculated visibility for this dobj -- instance in this iteration, then we do not need to -- recheck visibility. IF already check visibility for this dobj instance THEN return; END IF; -- Flush the S¯DOBJ¯INST table cache Call UTLNodeDObjlnstFlush() -- Compute visibility Run SQL rules, Check Dock Object rules. -- Reconcile S¯DOBJ¯INST table and do downloads/removes as needed -- If visibility has changed, stuff the value of TXN¯PROCESSED¯ID -- into S¯DOBJ.LAST¯CHK¯TXN¯ID -- NOTE: we can also stuff in the value of max(TXN¯ID) so we do not -- download txns affecting the dobj instance until after the -- current max(TXN¯ID) Call LOGReconcileDObjlnst() } DoPhase2 (NODE¯ID) -- Get status values so we can identify which txns to pre-process Get VIS¯CHECK¯RECORD from S¯DCK¯STAT -- new status for vis checks high water mark Get TXN¯PROCESSED¯ID from S DCK STAT for Node Id O -- Don't do anything if there are no new txns to process IF TXN¯PROCESSED¯ID = VIS¯CHECK¯RECORD THEN return; END IF; Open the .dx file for writing -- Get visibility event txns, and load visibility -- cache simultaneously -- SELECT tl.TXN¯ID, tl.OPERATION, tl.VIS¯EVT¯FLG, -- tl.DOBJ¯ID, tl.PR¯TBL¯ROW¯ID, di.STAT FLG, -- di.LAST¯CHK TXN ID¯ -- FROM S¯DOBJ¯INST di, -- $¯DCK¯TXN¯LOG tl -- WHERE tl.TXN ID > VIS¯CHECK¯RECORD - AND tl.TXN¯ID < = TXN¯PROCESSED¯ID -- AND tl.TXN¯ID < = VIS¯CHECK¯RECORD + batch¯size -- (Oracle & Informix) -- AND (tl.OPERATION in ('i', 'u') // set-based txn -- or tl.VIS EVT FLG = 'Y') -- AND tl.PR¯TBL¯ROW¯ID = di.PR¯TBL¯ROW¯ID (+) -- AND tl.DOBJ ID = di.DOBJ¯ID (+) -- AND tl.VIS ITEVEL FLG = 'L' /* limited visibility */ -- AND di.NODE ID (+) = :node id -- AND TXN ID > di.LAST¯CHK¯TXN¯ID -- ORDER BY tl.TXN¯ID -- NOTE: on Sybase, use set rowcount to limit batch size -- On Oracle & Informix, we assume that not many TXN¯ID -- values are lost if the db server crashes and restarts. numTxns := 0; Set VIS¯CHECK RECORD : = old VIS¯CHECK¯RECORD; FOR each vis event txn or set-based txn in the batch LOOP -- We got a set-based txn ProcessVisibilityEvent (tl.DOBJ ID, ts.PR¯TBL¯ROW¯ID, di.STAT¯FLG) END IF; IF amount written to .dx file > threshold THEN Close and compress the .dx file Increment LOG¯EXTRACT counter in S¯DCK¯STAT Add .dx file to list of files that were written (do not write to server.tx file yet) END IF; Set VIS¯CHECK¯RECORD = current txn id END LOOP; IF Phase3 is separate program THEN -- Do this part if Phase 3 is a separate program IF txns were downloaded/removed to the current .dx file THEN Close and compress the .dx file Increment LOG¯EXTRACT counter in S DCK STAT Add .dx file to list of files that were written ELSE Delete the . dx file END IF -- Commit at the end of the batch commit; END IF; ) Phase 3 is run once per mobile client per iteration, and extracts visible transactions for the mobile client. The following pseudocode describes the oper DoPhase3 (NODE ID) IF Phase2 is a separate program THEN Open the .dx file for writing END IF; -- Get status values so we can identify which txns to extract Get VIS¯CHECK¯RECORD from S¯DCK¯STAT Get EXTRACT¯RECORD from S DCK STAT -- SELECT tl.TXN¯ID - FROM S DCK TXN LOG tl -- WHERE tl.TXN ID > EXTRACT RECORD -- AND tl.TXN ID < = VIS CHECK RECORD -- AND (tl.VIS EVT PLG = 'E' /* enterprise visible */ -- or (tl.VIS¯EVT¯FLG = 'L' /* limited visible */ and exists (select 'visible' -- from S¯DOBJ¯INST di where tl.DOBJ ID = di.DOBJ¯ID and tl.PR TBL ROW ID = di.PR¯TBL¯ROW¯ID -- and di.NODE¯ID = 'node¯id' -- and tl.TXN ID > di.LAST¯CHK¯TXN¯ID) -- ORDER BY TXN¯ID ASC numTxns = 0; FOR each visible txn between EXTRACT¯RECORD and VIS¯CHECK¯RECORD LOOP Write the txn to the . dx file numTxns : = numTxns + 1; IF amount written to .dx file > threshold THEN Close and compress the .dx file Increment LOG¯EXTRACT counter in S¯DCK¯STAT Add .dx file to list of files that were written END IF; END LOOP; Set EXTRACT RECORD = VIS¯CHECK¯RECORD; IF txns were downloaded/removed/written THEN Close and compress the .dx file Increment LOG¯EXTRACT counter in S¯DCK¯STAT Add .dx file to list of files that were written ELSE Delete the . dx file END IF -- Commit at the end of the batch commit; Phase 4 is run once per iteration and deletes obsolete transactions from Transaction Log Table 300, including its substituent Transaction table 306 and Set Transaction ID table 308. The following pseudocode describes the operation of Phase 4 in detail. DoPhase4 0 -- Get status values so we can identify which txns to delete Get max(EXTRACT¯RECORD) from S¯DCK¯STAT Get max(EXTRACT¯RECORD) from last iteration -- No new txns to delete IF max(EXTRACT¯RECORD) = last iteration THEN return; END IF; -- DELETE FROM S¯DCK¯TXN¯LOG -- WHERE TXN ID < = max(EXTRACT RECORD) Delete from S¯DCK¯TXN¯LOG -- Commit at the end of the batch commit; Visibility Caching Improved performance may be obtained by providing a capability of caching recent visibility events. The S¯DOBJ¯INST table 63 is particularly suitable to provide such a "visibility cache." The existence of a particular docking object instance in S¯DOBJ¯INST table 63 may be used to assert that the docking object instance is visible to the mobile client. The visibility cache improves performance in two ways. First, it reduces the number of times visibility must be calculated. Log Manager 9 can use the cache in memory to determine visibility of a docking object instance when the transaction is on a table that does not cause implicit visibility events (i.e. the VISIBILITY EVT FLG is not checked for the table). Log Manager does not need to run any visibility SQL statements to determine the visibility of the transaction. Note that, if a transaction affects a table that can cause a visibility event, Log Manager must re-run the visibility SQL statements to determine that transaction's visibility. Second, the visibility cache reduces the number of SQL statements executed per visibility calculation. Log Manager uses the cache to determine visibility of check docking objects. Log Manager does not need to recursively run visibility rule SQL statements on each check docking object instance to determine the visibility of the transaction. Instead, Log Manager 9 joins to the S¯DOBJ¯INST table 63 to determine the visibility of check docking objects. As discussed earlier, the log manager uses two types of visibility rules, which can be summarized as SQL rules and Check-docking-object rules. An SQL rule is an SQL fragment that expresses whether the docking object instance is visible. An example of a visibility condition specified by an SQL rule for the opportunity docking object is "An Opportunity is visible if the sales rep is on the sales team." A checkdocking-object rule indicates that a docking object instance is visible if another docking object is visible. The definition of a check-docking-object rule contains a SQL fragment that tells the Log Manager how to get all the check docking objects for the docking object instance. An example of a visibility condition specified by a checkdocking-object rule for the opportunity docking object is "An Opportunity is visible if the Opportunity is used by a Quote that is visible to the sales rep." SQL rules are relatively inexpensive in execution resources. In contrast, Check-docking-object rules consume more resources and are therefore more expensive. In order to execute a check-docking-object rule, Log Manager recursively runs visibility SQL statements for the docking object it is checking. Determining visibility of a transaction can require running hundreds, or even thousands of SQL statements. Some objects may have eight to ten check-docking-object rules. Running all the visibility rule SQL statements for these objects could take between 0.25 seconds and several seconds for each mobile client. As the number of mobile clients increases, this can lead to undesirably low levels of service. Log Manager also uses the S¯DOBJ¯INST table to track whether a docking object instance (e.g., a particular Opportunity instance) has been downloaded to a mobile client. The S¯DOBJ¯INST table prevents Log Manager from downloading a docking object instance that was already previously downloaded, or removing a docking object instance that was already previously removed. The visibility cache is implemented in two ways. First, the S DOBJ¯INST table is used for transactions on non-visibility event tables. When checking visibility of a transaction, if the transaction is on a table that does not cause visibility events (S DOBJ TBL.VIS EVT FLG = 'N'), then the S¯DOBJ¯INST table is used to determine if the docking object instance is visible. If the docking object instance of the transaction exists in the S¯DOBJ¯INST table, then the transaction is visible to the mobile client. Otherwise, the transaction is not visible to the mobile client. The benefit is that the Log Manager does not need to run any visibility SQL rules or check-docking-object rules to determine the visibility. Second, the S¯DOBJ¯INST table is used to determine visibility of checkdocking-objects. Most of the check-docking-object rules may be converted to SQL rules that join the check-docking object to the S¯DOBJ¯INST table. If any checkdocking object exists in the S¯DOBJ¯INST table, then the check-docking object must be visible to the mobile client. The benefit is that the Log Manager runs at most one SQL statement to determine visibility of a check-docking object. The following example shows the benefits of the visibility cache. Without the visibility cache, the set of rules used to check visibility of a docking object representing an account might be expressed as the following four rules. Rule 1 (SQL): Account is visible if Account is a competitor: primary¯table.CMPT¯FLG = Rule 2 (SQL): Account is visible to sales rep if sales rep is on the Account Team: exists (select 'X' from S¯ACCNT¯POSTN ap, S¯EMP¯POSTN ep where ap.OU¯EXT¯ID = primary table.ROW ID and ep.EMP¯ID = :pemonid) Rule 3 (Check-Docking-Object): Account is visible if it is an account for an Opportunity that is visible: select OPTY¯ID from S¯OPTY¯ORG oo where OU¯ID = :primary¯row¯id Rule 4 (Check-Docking-Object): Account is visible if it is an account for a Quote that is visible: select ROW¯ID from S¯DOC¯QUOTE where OU¯ID = :primary¯row¯id To check the visibility of an Account docking object without a visibility cache, Log Manager performs the following steps to generate and execute SQL statements based on the above visibility rules. Step 1: OR together the SQL rules and execute the result: select 'X' from S¯ORG¯EXT primary table where primary¯table.ROW¯ID = :primary¯table¯row¯id and ((primaryJable.CMPT¯FLG = 'Y') or exists (select 'X' from S¯ACCNT¯POSTN ap, S¯EMP¯POSTN ep where ap.OU¯EXT¯ID = primary¯table.ROW¯ID and ep.EMP ID = :person¯id) Step 2: Execute Rule 3, the check-docking-object rule for the Opportunities object: select OPTY¯ID from S¯OPTY¯ORG oo where OU¯ID = :primary¯row¯id For each opportunity retrieved, execute the visibility rule SQL statements (SQL rules and check docking object rules) to determine whether the opportunity is visible. This can be many SQL statements. Step 3: Execute the check docking object rule for the Quotes object: select ROW¯ID from S¯DOC¯QUOTE where OU¯ID = :primary¯row¯id For each quote retrieved, the visibility rule SQL statements (SQL rules and check docking object rules) are executed to determine whether the quote is visible. This can be many SQL statements. The total number of SQL statements executed by this process may be computed as 1 + (Opty Check Objs * Opty vis rules) + (Quote Check Objs * Quote vis rules). This may be anywhere from one statement to several hundred statements, depending on the number of Opportunity and Quotes objects retrieved. With the visibility cache, the set of rules used to check visibility of a docking object representing an account might be expressed as the following four rules. The two SQL rules 1 and 2 are unchanged; the two check-dock-object rules have been replaced with SQL rules that interrogate the S DOBJ INST table. Rule 1 (SQL): Account is visible if Account is a competitor: primary¯table . CMPT¯FLG = Rule 2 (SQL): Account is visible to sales rep if sales rep is on the Account Team: exists (select 'X' from S¯ACCNT¯POSTN ap, S¯EMP¯POSTN ep where ap.OU¯EXT¯ID = primary¯table.ROW ID and ep.EMP¯ID = :person id) Rule 3 (SQL): Account is visible if it is an account for an Opportunity that is visible: exists (select 'X' from S¯OPTY¯ORG oo, S¯DOBJ¯INST di where oo.OU¯ID = :primary¯row¯id and oo.OPTY¯ID = di.PR¯TBL¯ROW¯ID and di.DOBJ ID = :dobjid and di.NODE¯ID = :nodeid) Rule 4 (SQL): Account is visible if it is an account for a Quote that is visible: exists (select 'X' from S¯DOC¯QUOTE q, S¯DOBJ¯INST di where q.OU¯ID = :primaryjow id and q.ROW ID = di.PR TBL ROW ID and di.DOBJ ID = :dobjid and di.NODE¯ID = :nodeid) To check the visibility of an Account docking object using a visibility cache, Log Manager generates and executes a single SQL statement derived from the four SQL rules. Log manager Ors together all four SQL rules to obtain a single SQL rule, as follows: select 'X' from S¯ORG¯EXT primary table where primary¯table.ROW¯ID = :primary table row id and ((primarytable.CMPT¯FLG = 'Y') or exists (select 'X' from S¯ACCNT¯POSTN ap, S¯EMP¯POSTN ep where ap.OU¯EXTJD = primary table.ROW¯ID and ep.EMP¯ID = :person¯id) or exists (select 'X' from S¯OPTY¯ORG oo S¯DOBJ¯INST di where oo.OU¯ID = :primaryjowJd and oo.OPTY¯ID = di.PR¯TBL¯ROW¯ID and di.DOBJ ID = :dobjid and di.NODE¯ID = :nodeid) or exists (select 'X' from S¯DOC¯QUOTE q, SPOBJ INST di where q.OU¯ID = : primary¯row¯id and q.ROW¯ID = di.PR¯TBL¯ROW¯ID and di.DOBJ ID = :dobjid and di.NODE¯ID = :nodeid) ) This single SQL statement accomplishes the same result as the potentially hundreds of SQL statements that would be required without the visibility cache. Because the SQL statements can get very large, it is advisable to establish a limit to the number of SQL rules that will be ORed together by Log Manager. This limit is preferably parameter-driven to permit ease of customization for a particular configuration. In some implementations, it may be useful to limit the number of tables in the SQL statement to about 16. The following SQL fragments each provide a mechanism for joining to the S¯DOBJ¯INST table. The fragment that is best for a particular implementation may vary depending on the performance characteristics for that implementation. Alternative 1: or (exists (select 'X' from S¯OPTY¯ORG oo S¯DOBJ¯INST di where oo.OU¯ID = :primary¯row¯id and oo.OPTY¯ID = di.PR TBL ROW ID and di.DOBJ ID = :checkdobjid and di.NODE¯ID = :nodeid) Alternative 2: or (exists (select 'X' from S¯DOBJ¯INST di where di.DOBJ¯ID = :checkdobjid and di.NODE¯ID = :nodeid and di.PR TBL ROW ID in ( select OPTY¯ID from S OPTY ORG oo where oo.OU¯ID = :primaryjowJd)) Alternative 3: or (exists (select OPTY¯ID from S¯OPTY¯ORG oo where oo.OU¯ID = :primary¯row¯id and OPTY¯ID in (select PR¯TBL ROW ID from S¯DOBJ¯INST di where di.NODE¯ID = :nodeid and di.DOBJ¯ID = : checkdobjid and di.STATUS¯FLG = :vistype)) The following pseudocode shows the algorithm for the visibility checking engine using the visibility cache. The algorithm is documented as four routines, denoted as CheckTxnVisibility, CheckObjectVisibility, CheckSqlRule and CheckOtherRule. CheckTxnVisibilitv -- Check if a record in the txn log is visible to a LaptopNodeId -- Also processes implicit visibility events and related dock objects static BOOL CheckTxnVisibility (LaptopNodeId, Table, RowId, *peVisible) C Find the Table in the Dictionary; IF Table not found THEN Error: Table not defined END IF; -- set to not visible by default *peVisible = 'None'; FOR all docking objects that the table belongs to LOOP -- Generate SQL to get PrimaryId values of the Docking Object GeneratePrimaryIdSQL (Table, RowId, DockingObject); FOR each PrimaryId value retrieved LOOP -- Enhancement &num;1: use cache for non-visibility events -- txn is for a table that does not cause visibility -- events and the txn is not an insert on the dock object's -- primary table (this is a new dock object instance). -- Do not need to do visibility calculation. No implicit -- visibility events and no related dock object processing IF Table.visibilityEventFlag = 'N' & & not an insert into DockObjectPrimaryTable THEN Find the object instance in the S¯DOBJ¯INST table IF status = 'Full' THEN 8peVisible = 'Full' ELSIF status = 'Partial' THEN *peVisible = 'Partial' ELSE *peVisible = 'None' END IF; ELSE -- Must recalculate visibility CheckObjectVisibility (LaptopNodeId, PrimaryTable, PrimaryRowId, depth = 0, peVisible); END IF; -- Process implicit visibility events and related dock objects ReconcileObjectInstance (LaptopNodeId, PrimaryTable, PrimaryRowId, & eVisible); -- If we need to process implicit visibility events, then -- continue looping through all docking objects even if we -- already know that the Txn is visible. IF *peVisible in ('Full', 'Partial') THEN IF Table.visibilityEventFlag = 'N' THEN return TRUE; END IF; END IF; END LOOP; END LOOP; return TRUE; ) CbeckObiectVisibility -- Check if a docking object instance is visible to the laptop user. BOOL CheckObjectVisibility (NodeId, DObjName, PrimaryRowId, depth, *peVisible) -- Algorithm: -- Check FULL visibility -- Use SQL Rules ORed together -- Use Check Dock Object Rules one by one -- Check PARTIAL visibility (iff depth == 0) -- Use SQL rules OR-ed together - Use Check Dock Object Rules one by one -- Flush the visibility cache to the S¯DOBJ¯INST table because -- the SQL rules will reference the cache. Flush the visibility cache to the S¯DOBJ¯INST table. -- Object is not visible. *peVisible = None; -- Check Visibility using SQL¯RULES ORed together CheckSqlRule (NodeId, DObjName, PrimaryRowId, peVisible, depth, UTL¯VIS¯FULL); IF *peVisible = = UTL¯VIS¯FULL THEN goto done; -- Check Visibility using Check Docking Objects CheckOtherRule (NodeId, DObjName, PrimaryRowId, peVisible, depth, UTL¯VIS¯FULL); IF *peVisible = = UTL¯VIS¯FULL THEN goto done; IF depth == 0 THEN /* Check Visibility using SQL¯RULES ORed together */ CheckSqlRule (NodeId, DObjName, PrimaryRowId, peVisible, depth, UTL¯VIS¯PARTIAL); IF *peVisible = = UTL¯VIS¯PARTIAL THEN goto done; /* Check Visibility using Check Docking Objects */ CheckOtherRule (NodeId, DObjName, PrimaryRowId, peVisible, depth, UTL¯VIS¯PARTIAL); IF *peVisible = = UTL¯VIS¯PARTIAL THEN goto done; END IF; done: return TRUE; } CheckSqlRule BOOL CheckSqlRule (NodeId, DObjName, PrimaryRowId, peVisible, depth, eVisType) -- Create the SQL statement -- "SELECT 'X' from < PrimaryTable > pt where -- pt.ROW¯ID = < primary table row id > " WHILE (TRUE) LOOP -- Build the SQL statement by ORing the SQL rules together. FOR each visibility rule for the Docking Object LOOP -- Only append SQL statements that match the VisType -- (Partial or Full) IF RuleType != SQLRule l l RuleLocalFlag | = eVisType THEN continue; END IF; -- Limit number of rules per statement to the one -- specified in the system preference. IF number¯rules¯appended = "LOG: vis rules per Stmt" THEN break; END IF; -- Add " < sql fragment > " to sql statement Append the SQL rule to the sql statement; END LOOP; -- Run the sql statement Run the select SQL statement using PrimaryRowId; IF any rows returned THEN -- row is visible *peVisible = eVisType; goto done; END IF; -- Stop if no more rules to run IF no more rules to append THEN break; END IF; END WHILE; done: return TRUE; } CheckOtherRule BOOL CheckOtherRule (NodeId, DObjName, PrimaryRowId, peVisible, depth, eVisType) { -- Run check docking object rules FOR each visibility rule for the Docking Object LOOP -- Only run sql statements that match the VisType -- (Partial or Full) IF RuleType != CheckDockObjectRule l l RuleLocalFlag != eVisType THEN continue; END IF; Run the ParameterSQL using PrimaryRowId to get newPrimaryRowId FOR each record retrieved by ParameterSQL LOOP -- recursively check visibility CheckObjectVisibility (LaptopNodeId, CheckDObjName, newPrimaryRowId, depth + 1, peVisible); -- Stop as soon as the object is found to be visible! IF *peVisible in ('Full', 'Partial') THEN goto done; END IF; END LOOP; done: return TRUE; De±rees of Visibility The docking process may be further enhanced by treating object visibility as a non-binary condition; that is, providing for an object to have a degree of visibility so that it may be visible in certain contexts and not visible in others. This may be provided for by associating a visibility strength with each dock object visibility rule. Visibility strength is a positive integer that states how visible a given dock object instance is. Visibility strength provides an alternative to concepts of fully and partially visible dock object instances. Rather than specifying visibility as either full or partial, visibility strengths allow for an unlimited range of visibility for an object. When a visibility rule passes, the dock object instance receives the visibility strength associated with the visibility rule. This visibility strength controls two aspects. The first aspect controlled by visibility strength is the downloading or removal of member table rows. Each member table also has a visibility strength. Docking downloads (or removes) member table rows only if the dock object instance visibility strength is greater or equal to the member table visibility strength. This aspect may be used to limit the number of member table rows replicated to docking clients. For example, when an Account is visible due to a Quote, docking should download the Account header, but does not need to download rows in the Account Notes, Account Positions, and other member tables. Log Manager download and removal processing is improved because Log Manager can skip downloading and removing certain member tables. In addition, docking replicates fewer rows to the docking clients, and the docking clients occupy less disk space. A second aspect controlled by visibility strength is the downloading or removal of related dock object instances. Each related dock object rule also has a visibility strength. When a dock object instance is visible, docking downloads (or removes) related dock object instances only if the dock object instance visibility strength is greater or equal to the related dock object rule visibility strength. This aspect may be used to follow a subsets of related dock objects depending on the reason why the dock object instance is visible. This allows docking to follow a subset of related dock objects even if a dock object instance is partially visible. Visibility strength is implemented by adding new attributes to the repository dock object table, dock object visibility rules and dock object related dock object rules. These new attributes specify the visibility strengths of member tables, visibility rules and related dock object rules. Each dock object visibility rule has a visibility strength. When a visibility rule passes, the dock object instance's visibility strength is equal to the highest visibility strength value of all visibility rules that pass. The dock object instance visibility strength specifies which member table rows to replicate to a docking client and which related dock object rules to run. Check dock object visibility rules also have a check-dock-object visibility strength. The check-dock-object visibility strength value specifies that the current dock object instance is visible only if the other dock object instance has a visibility strength greater than or equal to the check-dock-object visibility strength value. Visibility strength is indicated by an attribute VIS¯STRENGTH that specifies the strength of the dock object instance. The semantics of this attribute may vary depending on the context of the table in which it appears, as more fully discussed herein. VIS¯STRENGTH may have the following values: 0: not visible 5: partially visible 10: fully visible A number of the tables in the database schema are modified to support the VIS STRENGTH attribute. The S DOCK TABLE table stores the member tables for a docking object. Each docking object can have one or more member tables. The table contains an additional field, VIS¯STRENGTH. VIS¯STRENGTH is a numeric field containing the minimum visibility strength of the dock object instance for rows in this table to be downloaded. The field has a default value of 5, indicating that member table rows are downloaded if the dock object instance is partially visible. The S¯DOCK¯VIS¯RULE table stores the visibility rules for a docking object. Each docking object can have one or more visibility rules. The table contains an additional field, VIS¯STRENGTH. VIS¯STRENGTH is a numeric field containing the visibility strength of the dock object instance if the rule passes. The field has a default value of 5 (partially visible) if PARTIAL = 'y', and otherwise is set to 10. The S¯DOCK¯VIS¯RULE table also includes a CHECK¯VIS¯STRENGTH field, used for check-dock-object rules (i.e., rules with ruleType = 'C'). This value represents the minimum visibility strength of the check dock object instance to make this visibility rule pass. The field has a default value of 10, requiring the check dock object to be fully visible, for ruleType='C', and is otherwise unused and set to 0. The S DOCK REL OBJ table stores the related dock object rules for a docking object. Each docking object can have one or more related dock object rules. The table contains an additional field, VIS¯STRENGTH. VIS¯STRENGTH is a numeric field containing the minimum visibility strength of the dock object instance for Log Manager to run this rule. It has a default value of 10, requiring full visibility. The S¯DOCK¯REL¯OBJ table also includes a field REL¯VIS¯STRENGTH. This field contains a value that is used to provide a visibility strength value to related dock instances. It has a default value of 5. The S¯DOCK¯INST table is a new table replacing S¯DOBJ¯INST, and stores the current visibility strength of a dock object instance for each docking client. It has the following fields. NODE¯ID is a non-null unique key that indicates the docking client corresponding to this row. DOCK¯ID is a non-null unique key that indicates the dock object corresponding to this dock object instance. PR¯TBL¯ROW¯ID contains a key that is the primary table row id of the dock object instance. VIS¯STRENGTH is a numeric field containing the current visibility strength of the dock object instance for the docking client. The following SQL code may be used to define the S¯DOCK¯INST table: create table S¯DOCK¯INST ( NODE¯ID VARCHAR2(15) NOT NULL, DOCK¯ID VARCHAR2(30) NOT NULL, PR TBL ROW ID VARCHAR2(15) NOT NULL, VIS¯STRENGTH NUMBER NOT NULL create unique index S DOCK INST U1 on S DOCK INST (NODE¯ID, DOCK¯ID, PR TBL ROW¯ID, VIS¯STRENGTH); The S¯DCK¯TXN¯LOG table stores the transactions to route to docking clients. The table contains an additional field, VIS¯STRENGTH. VIS¯STRENGTH is a numeric field containing the visibility strength of the table referenced by the transaction. This value is denormalized by the Log Preprocessor and is used by the Log Router. It is only used in implementations using the Oracle" database. The following SQL code may be used to define the S¯DCK¯TXN¯LOG table: alter table S¯DCK¯TXN¯LOG add (TBL¯VIS STRENGTH NUMBER); Log Manager processing Log Manager routes a transaction to a docking client only if the dock object instance visibility strength is greater or equal to the member table visibility strength. The Log Preprocessor stores the member table visibility strength as a denormalized value in the transaction log table. When Log Router processes visibility events, visibility rules are executed in decreasing order of visibility strength until a visibility rule passes. When a visibility rule passes, the dock object instance receives the visibility strength of the visibility rule that passes. If no visibility rule passes, then the dock object instance gets a visibility strength of none (value = 0). After calculating the visibility strength, visibility strength of the dock object instance is written to the S¯DOCK¯INST table, unless the dock object instance has a visibility strength of 0. When Log Router searches for visible transactions, a transactions is fetched only if the S¯DOCK¯INST table has a visibility strength that is greater than or equal to the visibility strength of the transaction log denormalized member table. Log Manager uses the member table's visibility strength attribute to identify member table rows to download or remove: When the visibility strength of a dock object instance changes, Log Manager downloads or removes member table rows for the dock object instance. If the new visibility strength is greater than the old visibility strength, the referenced member table rows have not previously been downloaded and now should be downloaded. If the new visibility strength is less than the old visibility strength, then Log Manager removes member table rows that have previously been downloaded and should not now be downloaded. When processing related dock object rules, Log Manager uses the visibility strength attribute of each rule to identify which related dock object rules to execute. When the visibility strength of a dock object does not change and the visibility strength is not None, Log Manager checks related dock object instances and verifies that their visibility strength have not changed. When the visibility strength of a dock object instance changes, Log Manager checks all related dock object instances and downloads or removes related dock object instances as needed. If the new visibility st First, storing all docking visibility rules in the central dictionary lets both Log Manager and DBXtract use the same definitions to route transactions to mobile clients, reducing the cost of maintaining docking visibility rules. This also eliminates the need to maintain DBXtract SQL scripts for each different database vendor (e.g. 5based, Oracle", or Informix. Second, it permits the definition of pre-defined visibility rules commonly used by vendor-supplied applications. These rules make it unnecessary to enter SQL fragments or define related docking object rules. 90% of all docking visibility rules for typical applications may use pre-defined visibility rules. Third, the central dictionary lets customers use the Docking Object List view to easily customize docking visibility rules to satisfy site-specific requirements. Customers can also easily activate or deactivate visibility rules by changing an attribute of a visibility rule. With simplified visibiity rules, clients, such as end users, can change visibility rules using an easy-to-use graphical user interface. This improves performance for majority of customers by letting us define specialized visibility rules for a small set of customers as inactive rules and letting the customers activate the specialized rules. Customers that do not use the specialized rules do not incur the performance cost of the specialized rules. Fourth, storing all docking visibility rules in a unified location makes it easier to build future docking enhancements. Simplified docking rules are implemented as follows. Five new types of visibility rules are defined and stored in the central dictionary. 1) Check-dock-object rules relate two docking object instance to each other without the use of a SQL fragment. Check dock object rules are similar to SQL rules except that a check dock object definition between two docking objects is stored instead of a SQL fragment. For example, an opportunity is visible if an activity that is fully visible uses the opportunity. 2) Position rules specify that a docking object instance is visible if an employee on the docking client occupies a position for the docking object. For example, an opportunity is visible if an employee on the docking client is an opportunity sales team member. 3) Position manager rules specify that the docking object instance is visible if an employee on the docking client is the manager of an employee that occupies a position for the docking object. For example, an opportunity is visible if an employee on the docking client is the manager of an opportunity sales team member. 4) Employee rules specify that a docking object instance is visible if an employee on the docking client is assigned to the docking object. For example, an activity is visible if an employee on the docking client is assigned to the activity. Employee rules are typically used for owner, creator, etc. 5) Employee manager rules specify that the docking object instance is visible if an employee on the docking client is the manager of an employee assigned to the docking object. For example, an activity is visible if an employee on the docking client is the manager of an employee assigned to the activity. Employee manager rules are typically used for manager of owner, manager of creator, etc. In Log Manager, visibility SQL statements are generated from the central dictionary at runtime. Code is added to the visibility checker common API to generate and run SQL statements for the new visibility rule types. Log Manager's visibility event code is modified to use the new types of visibility rules to find related docking object instances. * Fig. 10 depicts a database diagram for the central dictionary. This diagram is akin to the schema of Fig. 2 with additional support added to the S DOCK VIS RULE table, as follows. The SPOCK VIS¯RULE table contains the visibility rules associated with a particular Docking Object. S DOCK VIS RULE 71 contains the additional fields DOCK ID, SEQUENCE, TYPE, ACTIVE and PARTIAL. Field DOCK ID identifies the Docking Object with which a particular visibility rule is associated, referred to as the "current docking object." Field SEQUENCE is a sequence number that indicates the sequence, relative to other visibility rules in the table, in which the particular visibility rule should be run. The ACTIVE field indicates whether a particular rule is active or not. A value of 'Y' or null indicates that the rule is active, and a value of 'N' indicates that it is inactive. The field TYPE specifies the type of the particular visibility rule. A value of 'S' indicates an SQL rule; a value '0' indicates a parameter dock object rule; a value 'C' indicates a check-dock-object rule; a value 'P' indicates a position rule; a value 'Q' indicates a position manager rule; a value 'E' indicates an employee rule; a value 'F' indicates an employee manager rule. The field PARTIAL, if set to 'Y', indicates that if the visibility rule is satisfied, the current docking object is partially visible. If set to 'N' or null, it indicates that if the visibility rule is satisfied, the current docking object instance is fully visible. In addition the S DOCK VIS RULE table contains a number of fields whose meaning and meaningfulness depends upon the rule type. SQL rules use the fields SQL STATEMENT and VIS EVT COLS. In this context, the SQL STATMENT field is an SQL fragment that, if it returns any rows, indicates that the dock object instance is visible. Parameter Dock Object Rules use the fields CHECK DOCK ID and SQL STATMENT. In this context, CHECK DOCK ID contains a pointer to another docking object and SQL STATEMENT contains an SQL statement to obtain the Primary values for the other dock object. For each PrimaryID retrieved, Log Manager runs the visibility rule of the other dock object. Check-Dock-Object rules use the fields CHECK DOCK ID, SRC¯COLUMN¯ID and TAR¯COLUMN¯ID. In this context, SRC COLUMN¯ID identifies the column in the current dock object that joins to the check dock object and TAR¯COLUMN¯ID identifies the column in the check dock object that joins to the dock object join column. For the Check-Dock-Object type, the visibility event columns is implicit: all columns needed to join from the primary table of the current dock object to the dock object join column. Position rules use the field POSTN¯COLUMN ID, which is a column in a member of table of the current dock object that points to the S¯POSTN table. For Position rules, the visibility event columns is implicit: all columns needed to join from the primary table of the current dock object to the position column. Position Manager rules use the field POSTN¯COLUMN¯ID, which is a column in a member of table of the current dock object that points to the S¯POSTN table. For Position Manager rules, the visibility event columns is implicit: all columns needed to join from the primary table of the current dock object to the position column. Employee rules use the field EMP¯COLUMN¯ID to identify a column in a member table of the current dock object that points to the S¯EMPLOYEE table. For Employee rules, the visibility event columns are implicit: all columns needed to join from the primary table of the current dock object to the employee column. Employee Manager rules use the field EMP¯COLUMN¯ID to identify a column in a member table of the current dock object that points to the S¯POSTN table. For Employee Manager rules, the visibility event columns is implicit: all columns needed to join from the primary table of the current dock object to the employee column. SQL statements are stored in the central dictionary memory structures for access by Log Manager and DBXtract. When the dictionary is loaded, SQL statements are generated and stored in the memory structures. Because the number of SQL statements are small, the generation code is expected to take less than one second. Alternatively, if the generation takes too long, the dictionary API may be modified to generate the SQL statements for a given dock object whenever the dock object is first referenced. Appendix B describes the format SQL statements that Log Manager generate at runtime and provide an example of these SQL statements using the Accounts dock object. CONCLUSION Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without the use of inventive faculty. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. All publications and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference. The invention now being fully described, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made thereto without departing therefrom. APPENDIX A Writing User Transaction Log File for a Given Laptop Node This program will be called by a server-side process that processes transaction log entries for all Laptop Nodes. For each Laptop Node, the calling process building the UserTrxnLogFileName and calling Program 1. input Parameters LaptopNodeId - node¯id of the destination laptop UserTxnLogFileName - full path of the file where txns will be written MaxBatchTxns - number of txns between commits and updates to the S¯DOCK¯STATUS table MaxTxns - number of txns to process in this session. Use this parameter to limit processing. Main Algorithm -- Check parameters IF (MaxTxns c 1 11 MaxBatchTxns < 1) ThEN Invalid Parameter END IF -- Get last LOG¯EXTRACT number for the Laptop from S¯DOCK¯STATUS last¯txn¯commit¯number = UTLDStatGetLogNum(LaptopNodeld); -- Initialize Variables NumTxns = 0; -- Total number of txns processed NumBatchTxns = 0; -- Total number of txns written in the current batch -- Read Docking Object and Table definitions into memory structures StartDictApi (); -- Open the User Log Txn file Open User Log Txn file -- Select and process new txns in S¯DOCK¯TRANSACTION¯LOG -- where txn commit number > last¯txn¯commit¯number FOR each new txn LOOP -- Stop processing if reach MaxTxns IF NumTxns = MaxTxns THEN break; END IF; -- Prevent circular txns. Do not send the txn back to the originating laptop IF txn.OriginNodeId = LaptopNodeId THEN Goto next transaction END IF; -- Process all other types of transactions -- This is the visibility calculator! -- This routine also processes implicit visibility events -- Later: Data Merge can call this function to check whether a txn is -- still visible when merging txns into a laptop or server database. Checkvisibility (LaptopNodeId, LogRecordType, TableName, TransRowId); IF txn is visible THEN -- Write transactions to UserTxnLog file depending on the -- type of LogRecordType. Write the txn to the user log file ++NumBatchTxns END IF; -- Finished processing the txn -- Commit (if needed) IF NumBatchTxns = MaxBatchTxns THEN -- Assume that separate process comes around and deletes -- Txns in S¯DOCK¯TRANSACTION¯LOG that have been processed -- for all nodes. So, no need to delete the txns from the log. Update last LOG¯EXTRACT number for Laptop in S¯DOCK¯STATUS Commit; NumBatchTxns = 0 END IF; + +NumTxns End Loop; /* Each transaction in the Txn Log table */ -- Commit Update last LOG¯EXTRACT number for Laptop in S¯DOCK¯STATUS Commit; -- Close log file (if needed) IF UserTxnLogFileP != NULL THEN Close File; END IF; StopDictApi (); Check Visibility Routines -- Check if a record in the txn log is visible to a LaptopNodeId BOOL CheckVisibility (LaptopNodeId, LogRecordType, TableName, TransRowId) -- SQLStatements routed based on the destination list IF LogRecordType in ('SQLStatement') THEN IF Laptop Node in destination list THEN return TRUE; END IF; -- Shadow and Multi Record LogRecordTypes are routed to all nodes -- No visibility events with these LogRecordTypes. ELSIF LogRecordType in ('ShadowOperation', 'MultiRecordDelete', 'MultiRecordUpdate') THEN return TRUE; -- Simple Deletes need more processing ELSIF LogRecordType in ('Simple Delete') THEN IF (table.visibility in ('Enterprise', 'Limited')) THEN return TRUE; END IF; -- Simple Inserts and Simple Updates need more processing -- CheckTxnVisibility() also processes implicit visibility events ELSIF LogRecordType in ('Simple Insert', 'Simple Update') THEN IF (table.visibility = 'Enterprise') THEN return TRUE; ELSIF table.visibility = 'Limited' THEN IF CheckTxnVisibility (LaptopNodeId, Table, RowId) THEN return TRUE; END IF; END IF; END IF; -- Check if a record in the txn log is visible to a LaptopNodeId static BOOL CheckTxnVisibility (LaptopNodeId, Table, RowId) BOOL bvisible = FALSE; Find the Table in the Dictionary; IF Table not found THEN Error: Table not defined END IF; FOR all docking objects that the table belongs to LOOP -- Generate SQL to get PrimaryId values of the Docking Object GeneratePrimaryIdSQL (Table, Rowid, DockingObject); FOR each PrimaryId value retrieved LOOP CheckObjectVisibility (LaptopNodeId, PrimaryTable, PrimaryRowId) IF object is visible THEN -- Because CheckObjectvisibility() also processes implicit -- visibility events, we must loop through ALL docking objects -- even if we already know that the Txn is visible. -- Exception: if the table has VIS event FLG = 'N' -- then we can return immediately. IF Table.visibilityEventFLG = 'N' THEN return TRUE; ELSE bVisible = TRUE; END IF; END IF; END LOOP; END LOOP; return bvisible; -- Check if an instance of a docking object is visible to the laptop user. -- Also processes implicit visibility events! BOOL CheckObjectVisibility (LaptopNodeId, DockingObjectName, PrimaryRowId) FOR each visibility rule for the Docking Object LOOP IF RuleType = RuleSQL THEN Run the select SQL statement using PrimaryRowId; IF any rows returned THEN -- row is visible -- Process an implicit Download Object DownloadObj ectInstance (LaptopNodeId, PrimaryTableName, PrimaryRowId); return TRUE; END IF; ELSIF RuleType = CheckDockingObject THEN Run the ParameterSQL using PrimaryRowId to get newPrimaryRowId FOR each record retrieved by ParameterSQL LOOP -- RECURSIVE! CheckObjectVisibility (LaptopNodeId, CheckDockingObjectName, newPrimaryRowId); IF rc = TRUE THEN -- Process an implicit Download Object DownloadObjectInstance (LaptopNodeId, PrimaryrableName, PrimaryRowId); return TRUE; END IF; END LOOP; END IF; END LOOP; -- Object is not visible. -- Process an implicit Remove Object RemoveObjectInstance (LaptopNodeId, PrimaryTableName, PrimaryRowId); return FALSE; Generate SQL Statement to Get PrimaryId -- Generate the SELECT SQL statement to get the PrimaryId value of -- the docking object for the given MemberTable -- SQL statement looks like: -- SELECT tp. < row id > -- FROM table¯owner > . < Table > tl, - - < table¯owner > . < PKTable > t2, ... one or more intermediate tables between the table - - and the PrimaryTable -- < table¯owner > . < PKTable > tN - - < table¯owner > . < PrimarylTable > tp -- WHERE tl.ROW¯ID = row id /* row¯id in transaction log */ -- /* join to PK table t2 */ -- AND tl. < FKColumn > = t2. < PKColumn > -- AND tl FKCondition > -- /* any number of joins until reach the table that joins -- to the PrimaryTable */ -- /* join from t2 to tN */ -- AND t2. < FKColumn > = tN. < PKColumn > -- AND < t2 FKCondition > -- /* join to the PrimaryTable */ -- AND tN. < FKColumn > = tp. < PKColumn > -- AND < tN FKCondition > -- Note that there may be one or more paths from the Member Table -- to the Primary Table. We need to generate a SQL select statement -- for each of the paths and UNION the statements together. -- This function assumes that there are no loops in the definition. -- These SQL statement do not change for each Table in a Docking Object, -- so we can calculate them one and store them in memory. struct CHAR* selectList; CHAR* fromClause; CHAR* whereClause; UINT numTables; /* also the number of joint to reach the Primary Table */ } GenStmt; GeneratePrimaryIdSQL (Table, DockingObject) /* there may be more than one SQL statement, so we have a dynamic array of SQL statements. Each element in the array is a path from the Table to the Primary Table*/ DynArrId GenStmtArr; GenStmt newGenStmt; CHAR* sqlStmt; DynArrCreate (GenStmtArr); -- Create the first element and initialize newGenStmt = malloc(); newGenStmt.numTables = 1; newGenStmt.selectList = "SELECT row¯id"; newGenStmt.fromClause = "FROM < Table > t1"; newGenStmt.whereClause = "WHERE t1.ROW¯ID = :row¯id"; DynArrAppend (GenStmtArr, & newGenStmt); /* Recursively follow FKs to the PrimaryTable */ Build the select, from and where clause simultaneously */ AddPKTable (Table, DockingObject, GenStmtArr, 0); -- Union all the paths together numStmts = DynArrSize (GenStmtArr); FOR all elements in the array LOOP tmpSqlStmt = GenStmtArrtj1 .selectList1 1 GenStmtArr[j] .fromClause GenStmtArr [j]. whereClause; sqlStmt = sqlStmt I 'UNION' || tmpSqlStmt; END LOOP; DynArrDestroy (GenStmtArr); IF sqlStmt = NULL THEN Error: no path from Table to Primary Table. END IF; -- Recursively follow all FKs to the Primary Table AddPKTable (Table, DockingObject, GenStmt, InputStmtNum) UINT numFKS = 0; UINT StmtNum; GenStmt newGenStmt; FOR all FKs for the table LOOP IF PKTable is a Member Table of the Docking Object THEN -- If there's more than one FK, then there is more than one path -- out of the current table. -- Copy the SQL stmt to a new DynArrElmt to create a new path IF numFKs > 0 THEN -- Create a new element and copy from GenStmt[InputStmtNum] newGenStmt = malloc(); newGenStmt.numTables = GenStmt[InputStmtNum].numTables; newGenStmt.selectList = GenStmt[InputStmtNum].selectList; newGenStmt.fromClause = GenStmt[InputStmtNum].fromClause; newGenStmt.whereClause = GenStmt[InputStmtNum].whereClause; DynArrAppend (GenStmtArr, & newGenStmt); StmtNum = DynArrSize (GenStmtArr); -- Put a check here for infinite loops IF StmtNum == 20 THEN Error: Probably got an Infinite loop? END IF; ELSE StmtNum = InputStmtNum; END IF; -- Append the new PKTable to the fromClause and whereClause GenStmt[StmtNum] .fromClause = GenStmt [StmtNum] .fromClause || ",\n < Table > t < numTables + 1 > "; GenStmt[StmtNum].whereClause = GenStmt [StmtNum] whereclause 1l "AND t < numTables > . < FKColumn > = t < numTables + 1 > . < PKColumn > " Ii "AND < FKCondition for Table if any > "; ++GenStmt.numTables; -- PKTable is the Primary Table then Done. IF PKTable = PrimaryTable THEN RETURN; ELSE AddPKTable (PKTable, DockingObject, GenStmt, StmtNum); END IF; -- Only count FKs to other member tables in the same Docking Object ++numFKs; END IF; END LOOP; RETURN; Process Visibility Events -- Download an Object Instance to a Laptop -- This function also downloads all Related Docking Object instances. BOOL DownloadObjectInstance (LaptopNodeId, ObjectName, PrimaryRowId) -- Check if the object instance is already downloaded to the laptop Find the object instance in the S¯DOBJ¯INST table IF exists on laptop THEN return TRUE; END IF; -- Register object instance in S¯DOBJ¯INST table -- Write Download Object records to the Txn Log FOR each member table of the docking object LOOP Generate SQL select statement to download records Write each retrieved record to the User Txn Log file END LOOP; -- Download records for Parent Object instances FOR each RelatedDockingObject LOOP Run ParameterSQL to get newPrimaryId of RelatedDockingObjects FOR each newPrimaryId retrieved LOOP -- Check if the instance of the object is visible to the laptop user CheckObjectVisibility (LaptopNodeId, ObjectName, PrimaryRowId) IF visible THEN DownloadObjectInstance (LaptopNodeId, RelatedDockingObject, newPrimaryRowId); END IF; END LOOP; END LOOP; return TRUE; -- Remove an Object Instance to a Laptop -- This function also removes all Related Docking Object instances. BOOL RemoveObjectInstance (LaptopNodeId, ObjectName, PrimaryRowId) -- Check if the object instance is already downloaded to the laptop Find the object instance in the S¯DOBJ¯INST table IF does not exist on laptop THEN return TRUE; END IF; -- Delete the object instance from S¯DOBJ¯INST table -- Write Remove Object records to the Txn Log FOR each member table of the docking object LOOP Generate SQL select statement to get records to delete Write each retrieved record to the User Txn Log file END LOOP; -- Remove for Parent Object instances FOR each RelatedDockingObject LOOP Run ParameterSQL to get newPrimaryId of RelatedDockingObjects FOR each newPrimaryId retrieved LOOP -- Check if the instance of the object is visible to the laptop user CheckObjectVisibility (LaptopNodeId, ObjectName, PrimaryRowId) IF not visible THEN RemoveObjectInstance (LaptopNodeId, RelatedDockingObject, newPrimaryRowId); END IF; END LOOP; END LOOP; return TRUE; Appendix B: SQL Statements and Examples Top Level SQL Statements This section describes the format SQL statements that Log Manager and DBXtract generates at runtime. See the next section for an example of these SQL statements using the Accounts dock object. Log Manager Visibility SOL Statements Log Manager generates visibility sql statements when checking the visibility of a dock object instance. Log Manager generates a < sub sql statement > for each visibility rule, the structure of which depends on the visibility rule type (see Sub SQL Statements below). select 'X' from & Table¯Owner. < primary table > primary table where primary table.ROW ID = < primary row id > and (( < sub sql statements 1) OR ( < sub sql statement 2 > ) OR ( < sub sql statement N > ) Log Manager Related Dock Object SQL Statements Log Manager generates related dock object sql statements after the visibility of a dock object instance has changed. Log Manager generates one or more < sub sql statements > for each visibility rule, the structure of which depends on the visibility rule type (see Sub SQL Statements below). < sub sql statements Sub-Statements for SQL Rules Log Manager Visibility SQL Statements < sql fragments Log Manager Related Dock Object SQL Statements User enters related dock object sql statements. DBXtract Phase 2 SQL Statements select DISTINCT pt.ROW¯ID ITEM¯ID¯T, < dobj¯id > ITEM¯TYPE¯T, :node id CREATED¯BY¯T, partial flag > PARTIAL¯FLG¯T from :table¯owner. < primary¯table > pt where < sql fragment > and pt.ROW¯ID not in (select di.ITEM¯ID from :table owner.S DCK INIT ITEM di where di.CREATED¯BY = :node¯id and di.ITEM¯TYPE = dobj¯id > ) Sub-Statements for Check Dock Object Rules Log Manager Visibility SOL Statements SQL Statement Template exists (select 'C' from & Tables & Table¯Owner.S¯DOBJ¯INST di where di.NODE¯ID = :node id and di.DOBJ¯ID = & Check DObj Id and di.STAT FLG = 'F' and di.PR¯TBL¯ROW¯ID = & Join¯Column & Joins Algorithm Build source and target dock object paths separately. Join source path to source primary table. Join target path to S DOBJ INST table. Then join source and target using the two join columns. Build Source object paths IF source join column table = source primary table THEN -- can optimize: join target object directly to primary table & Tables: add nothing & Joins : add nothing pSrcJoinCol = "primary¯table.csource join column > " ELSE Get paths from source join column table to source primary table. - The paths will not include the source primary table - The paths will not include the source join column & Tables: Add every table in path to from clause, last element first: " & Table¯Owner. < pathcol [N] - > pTable - > TableName > sNtt & Joins: - Add joins for all path cols except the last element: "and sN. < pathcol[N] - > pColumnName > = sN+l.ROW ID" - Add join from last element to primary rowid: "and s < last > . < pathcol [last] - > pColumnName > = primary table.ROW¯ID" pSrcJoinCol = "sl.csource join column > " END IF 1. Build Target object paths IF target join column = target primary table ROW¯ID THEN -- can optimize: join source object directly to S¯DOBJ¯INST table & Tables: add nothing & Joins : add nothing pTarJoinColumn: nothing & Join¯Column: pSrcJoinColumn ELSE Get paths from target join column table to target primary table. - The path will not include the target primary table if the path traverses any other member table. - The paths will not include the target join column. & Tables: Add every table in path, first element first ¯ " & Tables¯Owner. < pathcol [N] - > pTable- > pTableName > tN" & Joins: - Add joins for all path cols except the last element: "and tN+l.ROW¯ID = tN.pathcol [N] - > pColumnName" (note backwards order) pTarJoinColumn: "tl.cTarget join column > " & Join¯Column: "t < last > . < pathcol [last] - > pColumnName > " END IF 2. Join source and target join columns & Joins : Add join from target join column to source join column if both exist: "and < pTarJoinColumn > = < psrcJoinColumn > " 3. Replace & Tables, & Join¯Column and & Joins in the SQL statement template. Example 1: Opportunity visible due to Activity Source Object = Opportunity (src ptable: S¯OPTY) Target Object = Activity (tar ptable: S¯EVT¯ACT) Source join column = S¯OPTY.ROW¯ID Target join column = S¯EVT¯ACT.OPTY¯ID 1. Target Path: S¯EVT¯ACT.ROW¯ID & Tables: S¯EVT¯ACT tl & Joins : and di.PR¯TBL¯ROW¯ID = tl.ROW¯ID pTarJoinCol: tl.OPTY¯ID 2. Source Path: S¯OPTY.ROW¯ID & Tables: add nothing & Joins : add nothing pSrcJoinCol: primary table.ROW ID 3. Join source and target & Joins : and tl.OPTY¯ID = primary¯table.ROW¯ID select 'X' from & Table¯Owner.S¯OPTY primary¯table where ROW¯ID = ? and exists (select 'C' from & Table¯Owner.S¯EVT¯ACT t1, & Table¯Owner.S¯DOBJ¯INST di where di.NODE¯ID = node id and di.DOBJ¯ID = & Check¯Dobj¯Id and di.STAT FLG = 'F' and di.PR¯TBL¯ROW¯ID = tl.ROW¯ID and tl.OPTY¯ID = primary¯table.ROW¯ID) Example 2: Activity visible due to Opportunity Source Object = Activity (src ptable: S EVT ACT) Target Object = Opportunity (tar ptable: SIOPTY) Source join column = S¯EVT¯ACT.OPTY¯ID Target join column = S¯OPTY.ROW¯ID 1. Target Path: S¯OPTY.ROW¯ID & Tables: S¯OPTY tl & Joins : add nothing pTaraJoinCol: di.PR¯TBL¯ROW¯ID 2. Source Path: S¯EVT¯ACT.ROW¯ID & Tables: add nothing & Joins : add nothing pSrcJoinCol: primary table.OPTY ID 3. Join source and target & Joins: and di.PR¯TBL¯ROW¯ID = primary¯table.OPTY¯ID select 'X' from & Table¯Owner.S¯EVT¯ACT primary table where ROW¯ID = ? and exists (select 'C' from & Table¯Owner.S¯OPTY t1, & Table¯Owner.S¯DOBJ¯INST di where di.NODE¯ID = :node id and di.DOBJ¯ID = & & Table¯Owner.S¯DOBJ¯INST di where di.NODE¯ID = :node id and di.DOBJ¯ID = & Check¯Dobj¯Id and di.STAT FLG = 'F' and di.PR TBL ROW ID = tl.OU¯ID and tl.PRTNR OU ID = primary¯table.ROW¯ID) Example 4: Account visible due to Parent Account Source Object: Account (src ptable: S¯ORG¯EXT) Target Object: Account (tar ptable: S¯ORG¯EXT) Src join column: S¯ORG¯EXT.ROW¯ID Tar join column: S¯ORG¯EXT.PARENT OU ID 1. Target Path: S¯ORG¯EXT.ROW¯ID & Tables: S¯ORG¯EXT tl & Joins : and di.PR¯TBL ROW ID = tl.ROW¯ID pTarJoinCol: t1.PARENT¯OU¯ID 2. Source Path: S¯ORG¯EXT.ROW¯ID & Tables: add nothing & Joins : add nothing pSrcJoinCol: primary¯table.ROW ID 3. Join source and target & Joins: and tl.PARENT¯OU¯ID = primary¯table.ROW¯ID exists (select 'C' from & Table¯Owner.S¯ORG¯EXT t1, & Table¯Owner.SDOBJ¯INST di where di.NODE¯ID = :node id and di.DOBJ¯ID = & Check¯DObj¯Id and di.STAT FLG = 'F' and di.PR TBL ROW ID = tl.ROW¯ID and tl.PARENTOU¯ID = primary¯table.ROW¯ID) 3. Log Manager Related Dock Object SQL Statements SQL Statement Template select pt.ROW¯ID from & Tables & Joins Algorithm Build source and target dock object paths separately. Join target path to :primary¯row¯id. Join source and target using the two join columns. Get source primary table ROW¯ID. 1. Build Target object paths IF target join column = target primary table ROW¯ID THEN -- can optimize: join source object directly to :primary row id & Tables: add nothing & Joins : add nothing pTarJoinColumn = ":primary row id" ELSE Get paths from target join column table to target primary table. - The paths will not include the target primary table if the path traverses any other member table. - The paths will not include the target join column. & Tables: Add every table in path last element first ¯ " & Table¯Owner. < pathcol [N] - > pTable- > pTableName > tN" & Joins: - Add join from :primary¯row¯id to last path column: "and t < last > . < pathcol [0] - > pColumnName > = :primary row id" - Add joins for all path cols except the last element: "and tN+l.ROW¯ID = tN. < pathcol[N] > pColumnName > " (note backwards order) pTarJoinColumn: "tl. < Target join column > " END IF Build Source object paths Always add source primary table in join to guarantee that the source dock object instance exists IF source join column table = source primary table THEN -- optimize: can omit source tables from SQL statement & Tables: " < source primary table > pt" & Joins : add nothing pSrcJoinCol: "pt. < src join column > " ELSE Get paths from source join column table to source primary table. - The paths will not include the source primary table - The paths will not include the source join column & Tables: - Add every table in path to from clause, first element first: " & Table Owner. < pathcol[N]- > pTable- > pTableName > sN" - Add source primary table to from clause: " & Table¯Owner. < source primary table > pt" & Joins - Add joins for all path cols except the last element: "and sN. < pathcol [N] - > pColumnName > = sN+l.ROW ID" - Add join from last element to source primary table row¯id: "and s < last > .pathcol [last] - < pColumnName = pt.ROW¯ID" pSrcJoinCol = "sl. < Source join column > " END IF 3. Join source and target join columns & Joins: Add join from target join column to source join column: "and pTarJoinCol > = pSrcJoinCol > " Example 1: Opty visible due to Activity (Get all Opportunities for an Activity) Source Object = Opportunity (src ptable: S OPTY) Target Object = Activity (tar ptable: S¯EVT¯ACT) Source join column = S¯OPTY.ROW¯ID Target join column = S¯EVT¯ACT.OPTY¯ID 1. Source Path: S¯OPTY.ROW¯ID & Tables: S¯OPTY pt & Joins : add nothing pSrcJoinCol: pt.OPTY¯ID 2. Target Path: S¯EVT¯ACT.ROW¯ID & Tables: S¯EVT¯ACT tl & Joins : and :primary¯row¯id = tl.ROW¯ID pTarJoinCol: tl.OPTY¯ID 3. Join source and target & Joins : and tl.OPTY¯ID = pt.ROW¯ID select pt.ROW¯ID from & Table¯Owner.S¯EVT¯ACT tl, & Table¯Owner.S¯OPTY pt where :primary¯row¯id = tl.ROW¯ID and t1.OPTY¯ID = pt.ROW¯ID Example 2: Activity visible due to Opportunity (Get all Activities for an Opportunity) Source Object = Activity (src ptable: S EVT ACT) Target Object = Opportunity (tar ptable: S¯OPTY) Source join column = S¯EVT¯ACT.OPTY¯ID Target join column = S¯OPTY.ROW¯ID 1. Source Path: S¯EVT¯ACT.ROW¯ID & Tables: S¯EVT¯ACT pt & Joins : add nothing pSrcJoinCol: pt.OPTY¯ID 2. Target Path: S¯OPTY.ROW¯ID & Tables: add nothing & Joins : add nothing pTarJoinCol: :primary¯row¯id 3. Join source and target & Joins : and tl.OPTY¯ID = pt.ROW¯ID select pt.ROW¯ID from & Table¯Owner.S¯EVT¯ACT pt where :primary row id = pt.OPTY¯ID Example 3: Account visible due to Partner Account (Get all Accounts for a partner Account) Source Object: Account (src ptable: S¯ORG¯EXT) Target Object: Account (tar ptable: S-ORGEXT) Src join column: S¯ORG¯EXT.ROW ID Tar join column: S¯ORG¯REL.PRTNR¯OU¯ID 1. Source Path: S¯ORG¯EXT.ROW¯ID & Tables: S ORG EXT pt & Joins : add nothing pSrcJoinCol: pt.ROW¯ID 2. Target Path: S¯ORG¯REL.OU¯ID & Tables: S ORG REL tl & Joins : and :primaryl¯row¯id = tl.OU¯ID pTarJoinCol: tl.PRTNR¯OU¯ID 3. Join source and target & Joins : and tl.PRTNR¯OU¯ID = pt.ROW¯ID select pt.ROW¯ID from & Table¯Owner.S¯ORG¯REL t1, & Table¯Owner.S¯ORG¯EXT pt where :primary row id = tl.OU¯ID and t1. PRTNR¯OU¯ID = pt.ROWID Example 4: Account visible due to Parent Account (Get all Accounts for a Parent Account) Source Object: Account (src ptable: S¯ORG¯EXT) Target Object: Account (tar ptable: S¯ORG¯EXT) Src join column: S¯ORG¯EXT.ROW¯ID Tar join column: S¯ORG¯EXT.PARENT¯OU¯ID 1. Source Path: S¯ORG¯EXT.ROW¯ID & Tables: S ORG EXT pt & Joins : add nothing pSrcJoinCol: pt.ROW¯ID 2. Target Path: S¯ORG¯REL.ROW¯ID & Tables: S¯ORG¯EXT tl & Joins : and :primaryl¯row¯id = tl.ROW¯ID pTarJoinCol: tl.PARENT¯OU¯ID 3. Join source and target & Joins: and tl.PARENT¯OU¯ID = pt.ROW¯ID select pt.ROW¯ID from & Table¯Owner.S¯ORG¯EXT t1, & Table¯Owner.S¯ORG¯EXT pt where :primary row id = tl.ROW¯ID and t1.PARENT¯OU¯ID = pt.ROW¯ID Sub-Statements for Position Rules Log Manager Visibility SQL Statements SQL Statement Template exists (select 'X' from & Tables & Table¯Owner.S¯EMP¯POSTN ep, & Table¯Owner.SNODE EMP ne, & Table¯Owner.S¯NODE¯REL nr where nr.NODE ID = :node¯id and nr.SUB¯NODE¯ID = ne.NODE¯ID and ne.EMP¯ID = ep.EMP¯ID and ep.POSITION¯ID = & Join¯Column & Joins) Algorithm Build paths. Join path to primary¯table.ROW¯ID Join position column to position table. IF position column table = primary table THEN -- can optimize: join primary table directly to S¯EMP¯POSTN & Tables: add nothing & Joins : add nothing & join¯Column: "primary¯table. < position column > " ELSE Get paths from position column table to primary table. - The paths will not include the primary table - The paths will not include the position column & Tables Clause: - Add every table in path, last element first " & Table Owner.pathcol[N]- > pTable- > pTableName jN" & Joins Clause: - Add joins for all path cols except the last element: "and jN. < pathcol[N]- > pColumnName > = jN+l.ROW¯ID" - Add join from last element to primary rowid: "and j < last > . < pathcol [last] - > pColumnName > = primaryl¯table.ROW¯ID" & Join¯Column: "jl. < position column > " END IF Replace & Tables, & Join¯Column and & Joins in the SQL statement template. Example 1: Opportunity Position Object: Opportunity (primary table: S¯OPTY) Position Column: S¯OPTY¯POSTN.POSTN¯ID Path Cols: S¯OPTY¯POSTN.OPTY¯ID & Tables: S¯OPTY¯POSTN jl & Joins: and j1. OPTY¯ID = primary¯table.ROW¯ID & Join¯Column: j1.POSTN¯ID exists (select 'X' from & Table¯Owner.S¯OPTY¯POSTN j1, & Table¯Owner.S¯EMP¯POSTN ep, & Table¯Owner.S¯NODE¯EMP ne, & Table¯Owner.S¯NODE¯REL nr where nr.NODE ID = :ode Td and nr.SUB¯NODE¯ID = ne.NODE¯ID and ne.EMP¯ID = ep.EMP¯ID and ep.POSITION¯ID = jl.POSTN¯ID and jl.OPTYID = primary¯table.ROW¯ID) Example 2: Quote Position Object: Quote (ptable: S¯DOC¯QUOTE) Position Column: S¯DOC¯QUOTE.POSTN¯ID Path: S¯DOC¯QUOTE.ROW¯ID & Tables: none & Joins: none & Join¯Column: primary¯table.POSTN¯ID exists (select 'X' from & Table¯Owner.S¯EMP¯POSTN ep, & Table¯Owner.S¯NODE¯REL nr, & Table¯Owner.S¯NODE¯EMP ne where nr.NODE ID = :node¯id and nr.SUB¯NODE¯ID = ne.NODE¯ID and ne.EMP¯ID = ep.EMP¯ID and ep.POSITION¯ID = primary table.POSTN ID) Log Manager Related Dock Object SOL Statements SQL Statement Templates Node to Current Dock Object select pt.ROW¯ID from & Table¯Owner.S¯NODE¯REL join¯table, & Table¯Owner.S¯NODE¯EMP ne, & Table¯Owner.S¯EMP¯POSTN ep, & Tables where join¯table.NODE¯ID = :node id and join¯table.NODE¯ID = : primary¯row¯id and join¯table.SUB¯NODE¯ID = ne.NODE¯ID and ne.EMP ID = ep.EMP¯ID and ep.POSITION¯ID = & Join¯Column & Joins Algorithm Build paths. Join path to pt.ROWjD. Join position column to position table. Always join to primary table so the statement only returns related objects that really exist. E.g. only retrieve Opportunities that really exist. IF position column table = primary table THEN -- can optimize: join primary table directly to S¯EMP¯POSTN & Tables: primary table > pt & Joins: empty & Join¯Column: "pt. < position column > " ELSE Get paths from position column table to primary table. - The paths will not include the primary table - The paths will not include the position column & Tables Clause: - Add every table in path first element first " & Table¯Owner. < pathcol [N] - > pTable- > pTableName > " - Add primary table: primary table > pt & Joins Clause: - Add joins for all path cols except the last element: "and jN. < pathcol[N]- > pColumnName > = jN+l.ROW¯ID" - Add join from last element to primary rowid: "and j < last > . < pathcol[last]- > pColumnName > = pt.ROW¯ID" & Join¯Column: "jl. < position column > " END IF Replace & Tables, & Join¯Column and & Joins in the SQL statement template. Example 1: Opportunity Position Object: Opportunity (ptable: S¯OPTY) Position Column: S¯OPTY¯POSTN.POSTN¯ID Path: S¯OPTY¯POSTN.OPTY¯ID & Tables: S¯OPTY¯POSTN ji, S¯OPTY pt & Joins : and jl.OPTY¯ID = pt.ROW¯ID & Join¯Column:: jl.POSTN¯ID select pt.ROW¯ID from & Table¯Owner.S¯NODE¯REL join table, & Table¯Owner.S¯NODE¯EMP ne, & Table¯Owner.S¯EMP¯POSTN ep, & Table¯Owner.S¯OPTY¯POSTN jl, & Table¯Owner.S¯OPTY pt where join¯table.NODE¯ID = :node¯id and join¯table.NODE-ID = :primary row id and jointable SUB ODE ID = ne.NODE¯ID and ne.EMP¯ID = ep.EMP¯ID and ep.POSITION¯ID = jl.POSTN¯ID and jl.OPTY¯ID = pt.ROW¯ID) Example 2: Quote Position Object: Quote (ptable: S DOC¯QUOTE) Position Column: S¯DOC¯QUOTE.POSTN¯ID Path: S¯DOC¯QUOTE.ROW¯ID & Tables: S¯DOC¯QUOTE pt & Joins : none & Join¯Column: pt.POSTN¯ID select pt.ROW¯ID from & Table¯Owner.S¯NODE¯REL join table, & Table¯Owner.S¯NODE¯EMP ne, & Table¯Owner.S¯EMP¯POSTN ep, & Table¯Owner.S¯DOC¯QUOTE pt where join¯table.NODE¯ID = :node¯id and join¯table.NODE¯ID = : primary¯row¯id and join¯table.SUB¯NODE¯ID = ne.NODE¯ID and ne.EMP¯ID = ep.EMP¯ID and ep.POSITION¯ID = pt.POSTN¯ID) Sub-Statements for Position Manager Rules Log Manager Visibility SQL Statements SQL Statement Template exists (select 'X' from & Tables & Table¯Owner.S POSTN RPT REL prr, & Table¯Owner.S¯EMP¯POSTN ep, & Table¯Owner.S¯NODE EMP ne, & Table¯Owner.S¯NODE¯REL nr where nr.NODE¯ID = :node id and nr.SUB¯NODE¯ID = ne.NODE¯ID and ne.EMP¯ID = ep.EMP¯ID and ep.POSITION¯ID = prr.POSITION¯ID and prr.SUB¯POSTN¯ID = & Join¯Column & Joins) Algorithm Same as Position Rule algorithm, except we use the SQL statement template above. Log Manager Related Dock Object SOL Statements SQL Statement Templates Node to Current Dock Object select pt.ROW¯ID from & Table¯Owner.S¯NODE¯REL join¯table, & Table¯Owner.S¯NODE¯EMP ne, & Table¯Owner.S¯EMP¯POSTN ep, & Table-Owner.S-POSTN RPT REL prr & Tables where jointable.NODE ID = :node¯id and join¯table.NODE¯ID = :primary¯row¯id and join¯table.SUB¯NODE¯ID = ne.NODE¯ID and ne.EMP ID = ep.EMP¯ID and ep.POSITION¯ID = prr.POSITION¯ID and prr.SUB¯POSTN¯ID = & Join¯Column & Joins Employee to Current Dock Object select pt.ROW¯ID from & Table¯Owner.S¯NODE¯REL nr, & Table¯Owner.S¯NODE¯EMP ne, & Table¯Owner.S¯EMP¯POSTN ep, & Table¯Owner.S¯POSTN¯RPT¯REL prr & Tables where nr.NODE¯ID = :node¯id and nr.SUB¯NODE¯ID = ne.NODE¯ID and ne.EMP¯ID = ep.EMP¯ID and ep.EMP¯ID = : primary¯row¯id and ep.POSITION¯ID = prr.POSITION¯ID and prr.SUB¯POSTN¯ID = & Join¯Column & Joins / Position to Current Dock Object select pt.ROW ID from & Table¯Owner.S¯NODE¯REL nr, & Table¯Owner.S¯NODE¯EMP ne, & Table¯Owner.S¯EMP¯POSTN ep, & Table¯Owner.S¯POSTN¯RPT¯REL join¯table & Tables where nr.NODE¯ID = :node¯id and nr.SUB¯NODE¯ID = ne.NODE¯ID and ne.EMP¯ID = ep.EMP¯ID and ep.POSITION¯ID = :primary¯row¯id and join¯table.POSITION¯ID = : primary¯row¯id // help sybase by providing value and join¯table.SUB¯POSTN¯ID = & Join¯Column & Joins / Algorithm Same as Position Rule algorithm, except we create related dock objects from Nodes, Employees, Positions and use the SQL statement templates above. Sub-Statements for Employee Rules Log Manager Visibility SQL Statements SQL Statement Template exists (select 'X' from & Tables & Table¯Owner.S¯NODE¯EMP ne, & Table¯Owner.S¯NODE¯REL nr where nr.NODE ID = :node¯id and nr.SUB¯NODE¯ID = ne.NODE¯ID and ne.EMP¯ID = & Join¯Column & Joins) Algorithm Same as Position Rule algorithm, except we use the SQL statement template above. Log Manager Related Dock Object SQL Statements SQL Statement Templates Node to Current Dock Object select pt.ROW¯ID from & Table¯Owner.S¯NODE¯REL join¯table, & Table¯Owner.S¯NODE¯EMP ne & Tables where join¯table.NODE¯ID = :node id and join¯table.NODE¯ID = :primaryrow id and join¯table.SUB¯NODE¯ID = ne.NODE¯ID and ne.EMP¯ID = & Join¯Column & Joins Algorithm Same as Position Rule algorithm, except we use the SQL statement template above. Sub-Statements for Employee Manager Rules Log Manager Visibility SQL Statements SQL Statement Template exists (select 'X' from & Tables & Table¯Owner.S¯EMP¯POSTN psub, & Table-Owner.S-POSN RPT REL prr, & Table¯Owner.S¯EMP¯POSTN pmgr, & Table¯Owner.S¯NODE¯EMP ne, & Table¯Owner.S¯NODE¯REL nr where nr.NODE ID = :node id and nr.SUB NODE ID = ne.NODE¯ID and ne.EMP¯id = pmgr.EMP¯ID and pmgr.POSITION¯ID = prr.POSITION¯ID and prr.SUB¯POSTN¯ID = psub.POSITION¯ID and psub.EMP¯ID = & Join¯Column & Joins) Algorithm Same as Position Rule algorithm, except we use the SQL statement template above. Log Manager Related Dock Object SQL Statements SQL Statement Templates Node to Current Dock Object select pt.ROW¯ID from & Table¯Owner.S¯NODE¯REL join¯table, & Table¯Owner.S¯NODE¯EMP ne, & Table¯Owner.S¯EMP¯POSTN pmgr, & Table¯Owner.S¯POSTN¯RPT¯REL prr, & Table¯Owner.S¯EMP¯POSTN psub & Tables where join¯table.NODE¯ID = :node id and join¯table.node¯ID = : primary¯row¯id and join¯table.SUB¯NODE¯ID = ne.NODE¯ID and ne.EMP ID = pmgr.EMP¯ID and pmgr.POSITION¯ID = prr.POSITION¯ID and prr.SUB¯POSTN¯ID = psub.POSITION¯ID and psub.EMP¯ID = & Join¯Column & Joins Employee to Current Dock Object select pt.ROW¯ID from & Table¯Owner.S¯NODE¯REL nr, & Table¯Owner.S¯NODE¯EMP ne, & Table¯Owner.S¯EMP¯POSTN psub, & Table¯Owner.S¯POSTN¯RPT¯REL prr, & Table¯Owner.SrEMP¯POSTNpmgr & Tables where nr.NODE¯ID = :node¯id and nr.SUB¯NODE¯ID = ne.NODE¯ID and ne.EMP¯ID = pmgr.EMP¯ID and pmgr.EMP ID = : primary¯row¯id and pmgr.POSITION¯ID = prr.POSiTION¯ID and prr.SUB¯POSTN¯ID = psub,POSITION¯ID and psub.EMP¯ID = & Join¯Column & Joins / Position to Current Dock Object select pt.ROW¯ID from & Table¯Owner.S¯NODE¯REL nr, & Table¯Owner.S¯NODE¯EMP ne, & Table¯Owner.S¯EMP¯POSTN psub, & Table¯Owner.S¯POSTN¯RPT¯REL join¯table, & Table¯Owner.S¯EMP¯POSTN pmgr & Tables where nr.NODE¯ID = :node¯id and nr.SUB¯NODE¯ID = ne.NODE¯ID and ne.EMP¯ID = pmgr.EMP¯ID and pmgr.POSITION¯ID = :primaryrowJd and join¯table.POSITION¯ID = : primary¯row¯id // help sybase by providing value and join¯table.SUB¯POSTN¯ID = psub.POSITION¯ID and psub.EMP¯ID = & loin¯Column & Joins / Algorithm Same as Position Rule algorithm, except we create related dock objects from Nodes, Employees, Positions and use the SQL statement templates above. Example Here are examples of visibility rules for the Account docking object and sql statements that Log Manager and DBXtract generate for each visibility rule. Visibility Rules for Organization EMI76.1 <SEP> Rule <SEP> Rule <SEP> Partial <SEP> Sqi <SEP> Statement <SEP> Check <SEP> Check <SEP> Dock <SEP> Check <SEP> Dock <SEP> Position <SEP> Emp <tb> <SEP> &num; <SEP> Type <SEP> Flag <SEP> Object <SEP> Object <SEP> Object <SEP> Target <SEP> Column <SEP> Col <tb> <SEP> Source <SEP> Column <tb> <SEP> Column <tb> <SEP> 1 <SEP> Sql <SEP> N <SEP> primary¯table.CMP <tb> <SEP> T¯FLG <SEP> = <SEP> 'Y' <tb> <SEP> 2 <SEP> Positio <SEP> N <SEP> S¯ACCNT¯ <tb> <SEP> n <SEP> POSTN <tb> <SEP> POSITION <tb> <SEP> ¯ID <tb> <SEP> 3 <SEP> Positio <SEP> N <SEP> S¯ORG¯EX <tb> <SEP> n <SEP> T <tb> <SEP> Mana <SEP> PR¯POSTN <tb> <SEP> ger <SEP> ¯ID <tb> <SEP> 4 <SEP> Check <SEP> Y <SEP> Contac <SEP> S¯ORG¯EX <SEP> S¯CONTACT <tb> <SEP> Dock <SEP> t <SEP> T <SEP> PR¯DEPT¯OU <tb> <SEP> Object <SEP> ROW¯ID <SEP> ¯ID <tb> <SEP> 5 <SEP> Check <SEP> Y <SEP> Contac <SEP> S¯ORG¯EX <SEP> S¯PER¯ORG¯ <tb> <SEP> Dock <SEP> t <SEP> T <SEP> UNIT <tb> <SEP> Object <SEP> ROW¯ID <SEP> OU¯ID <tb> 6 <SEP> Check <SEP> Y <SEP> Accoun <SEP> S¯ORG¯EX <SEP> S¯ORG¯REL <tb> <SEP> Dock <SEP> t <SEP> T <SEP> PRTNR¯OU¯I <tb> <SEP> Object <SEP> ROW¯ID <SEP> D <tb> Rule Descriptions 1. Rule 1: Account is a competitor 2. Rule 2: Sales rep is on the account team 3. Rule 3: Manager of the primary sales rep on the Account 4. Rule 4: Primary Account for a Contact you have visibility on 5. Rule 5: Secondary Account for a Contact you have full visibility on 6. Rule 6: Account for a partner Account you have full visibility on 6. Log Manager Visibility SQL Statements Log Manager runs the rule sql statements OR-ed together: select 'X' from & Table¯Owner. < primary table > primary¯table where primary¯table.ROW¯ID = < primary¯row¯id > rule 1 and ((primary¯table.CMPT¯FLG = 'Y') OR (exists (select 'X' // rule 2 from & Table¯Owner.S¯NODE¯REL nr, & Table¯Owner.S¯NODE¯EMP ne, & Table¯Owner.S¯EMP¯POSTN ep, & Table¯Owner.S¯ACCNT¯POSTN j1 where nr.NODE¯ID = : node id and nr.SUB¯NODE¯ID = ne.NODE¯ID and ne.EMP¯ID = ep.EMP¯ID and ep.POSITION¯ID = jl.POSITION¯ID and jl.OU¯ID = primary¯table.ROW¯ID) OR (exists (select 'X' // rule 3 from & Table¯Owner.S¯NODE¯REL nr, & Table¯Owner.S¯NODE¯EMP ne, & Table¯Owner.S¯EMP¯POSTN ep, & Table¯Owner.S¯POSTN¯RPT¯REL prr where nr.NODE¯ID = :node id and nr.SUB¯NODE¯ID = ne.NODE¯ID and ne.EMP¯ID = ep.EMP¯ID and ep.POSITION¯ID = prr.POSITION¯ID and prr.SUB¯POSTN¯ID = primary table.PR POSTN ID) OR (exists (select 'C' // rule 4 from & Table¯Owner.S¯DOBJ¯INST di, & Table¯Owner.S¯CONTACT tl where di.NODE¯ID = : node¯id and di.DOBJ¯ID = < Contact Dock Object Id > and di.STAT FLG = 'F' and di.PR TBL ROW ID = tl.ROW ID and tl.PR¯DEPT OU ID = primary¯table.ROW¯ID) OR (exists (select 'C' // rule 5 from & Table¯Owner.S¯DOBJ¯INST di, & Table¯Owner.S¯PER¯ORG¯UNIT tl where di.NODE¯ID = :node¯id and di.DOBJ¯ID = < Contact Dock Object Id > and di.STAT FLG = 'F' and di.PR¯TBL¯ROW¯ID = tl.PER¯ID and tl.OU¯ID = primary¯table.ROW¯ID) OR (exists (select 'C' rule 6 from & Table¯Owner.S¯DOBJ¯INST di, & Table¯Owner.S¯ORG¯REL tl where di.NODE¯ID = : node¯id and di.DOBJ¯ID = < Account Dock object Id > and di.STAT¯FLG = 'F' and di.PR¯TBL¯ROW¯ID = tl.OU ID and tl.PRTNR¯OU¯ID = primary¯table.ROW¯ID) Log Manager Related Dock Object SQL Statements Nodes select pt.ROW¯ID // rule 2 from & Table¯Owner.S¯NODE¯RELjoin, & Table¯Owner.S¯NODE¯EMP ne, & Table¯Owner.S¯EMP¯POSTN ep, & Table¯Owner.S¯ACCNT¯POSTNj1, & Table¯Owner.S¯ORG¯EXT pt where join¯table.NODE¯ID = :node¯id and join¯table.NODE¯ID = : primary¯row¯id and join¯table.SUB¯NODE¯ID = ne.NODE¯ID and ne.EMP¯ID = ep.EMP¯ID and ep.POSITION¯ID = j1.POSITION¯ID and j1.OU¯ID = pt.ROW¯ID / select pt.ROW¯ID // rule 3 from & Table¯Owner.S¯NODE¯REL join¯table, & Table¯Owner.S¯NODE¯EMP ne, & Table¯Owner.S¯EMP¯POSTN ep, & Table¯Owner.S¯POSTN¯RPT¯REL prr, & Table¯Owner.S¯ORG¯EXT pt where join¯table.NODE ID = :node¯id and join¯table.NODE¯ID = : primary¯row¯id and join¯table.SUB¯NODE¯ID = ne.NODE¯ID and ne.EMP ID = ep.EMP ID and ep.POSITION¯ID = prr.POSION¯ID and prr.SUB¯POSTN¯ID = pt.RR¯POSTN¯ID / # Employees select pt.ROW¯ID // rule 3 from & Table¯Owner.S¯NODE¯REL nr, & Table Owner.S¯NODE ne, & Table¯Owner.S¯EMP¯POSTN ep, & Table¯Owner.S¯POSTN¯RPT¯RELprr, & Table¯Owner.S¯ORG¯EXT pt where nr.NODE¯ID = node id and nr.SUB¯NODE¯ID = ne.NODE ID and ne.EMP¯ID = ep.EMP¯ID and ep.EMP¯ID = : primary¯row¯id and ep.POSITION¯ID = prr.POSION¯ID and prr.SUB¯POSTN¯ID = pt.PR¯POSTN¯ID / Positions select pt.ROW¯ID // rule 3 from & Table¯Owner.S¯NODE¯RELnr, & Table¯Owner.S¯NODE¯EMP ne, & Table¯Owner.S¯EMP¯POSTN ep, & Table¯Owner.S¯POSTN¯RPT¯REL join¯table, & Table¯Owner.S¯ORG¯EXT pt where nr.NODE¯ID = :node¯id and nr.SUB¯NODE¯ID = ne.NODE¯ID and ne.EMP¯ID = ep.EMP¯ID and ep.POSITION¯ID = :primary¯row¯id and join¯table.POSITION¯ID = :primary¯row¯id and join¯table.SUB¯POSTN¯ID = pt.PR¯POSTN¯ID / # Contacts select pt.ROW¯ID // rule 4 from & Table¯Owner.S¯CONTACT tl, & Table¯Owner.S¯ORG¯Exr pt where : primary row¯id = tl.ROW¯ID and t1.PR¯DEPT¯OU¯ID = pt.ROW¯ID / select pt.ROW¯ID // rule 5 from & Table¯Owner.S¯PER¯ORG¯UNIT t1, & Table¯Owner.S¯ORG¯EXT pt where :primary¯row¯id = t1.PER¯ID and t1.OU¯ID = pt.ROW¯ID / # Accounts select pt.ROW¯ID // rule 6 from & Table¯Owner.S¯ORG¯REL tl, & Table¯Owner.S¯ORG¯EXT pt where :primary¯row¯id = t1.OU¯ID and t1.PRTNR¯OU¯ID = pt.ROW¯ID /

Claims: CLAIMS 1. A method of managing a database, said database including a central database (3) and separate partially replicated databases (23a, 23b, 23c), said separate partially replicated databases having separate users (33a, 33b, 33c), comprising determining from a set of visibility rules, the visibility of a user (33a, 33b, 33c) of a partially replicated database (23a, 23b, 23c) to data being propagated, and propagating said data to a partially replicated database (23a, 23b, 23c) only if the user (33a, 33b, 33c) of the partially replicated database (23a, 23b, 23c) has visibility to the data. 2. The method of claim 1 where the set of visibility rules is stored at a single location. 3. The method of claim 1 comprising determining the visibility of a user (33a, 33b, 33c) of a partially replicated database (23a, 23b, 23c) that is not being updated but that is related to a partially replicated database (23a, 23b, 23c) that is being updated. 4. The method of claim 2 comprising recursively determining the visibility of a user (33a, 33b, 33c) of a partially replicated database (23a, 23b, 23c) that is being updated. 5. The method of claim 1 wherein the visibility of a node (33a, 33b, 33c) of a partially replicated database (23a, 23b, 23c) is in declarative form. 6. The method of claim 1 comprising storing in cache memory the visibility of a node (33a, 33b, 33c) of a partially replicated database (23a, 23b, 23c) to data being propagated. 7. The method of claim 1 wherein the said nodes (33a, 33b, 33c) of the partially replicated databases (23a, 23b, 23c) have a visibility strength to data being propagated. 8. The method of claim 1 comprising storing at least one set of visibility rules in a single location. 9. The method of claim 1 comprising storing the visibility rules against the data content of a related docking object that is not to be updated to determine the visibility of a docking object that is to be updated. 10. The method of claim 1 comprising storing visibility rules by storing them in a central dictionary, to allow the nodes (33a, 33b, 33c) to change the visibility rules. 11. The method of claim 1 comprising using a graphical user interface to change the visibility rules. 12. The method of claim 9 comprising using a graphical user interface to change the visibility rules. 13. An article of manufacture comprising a computer usable medium having computer usable program code embodied therein for managing a partially replicated database (23a, 23b, 23c) by determining the visibility of a user of the database to data in the database and propagating visibility of the data in accordance therewith, the computer readable program means in said article of manufacture comprising: computer readable program code means for causing a computer to effect determining from a set of visibility rules stored at a single location the visibility of a user of the partially replicated database (23a, 23b, 23c); and computer readable program code means for causing the computer to effect propagating the data to the partially replicated database (23a, 23b, 23c) if the user of the partially replicated database (23a, 23b, 23c) has visibility to the data. 14. A program storage device readable by a machine, tangibly embodying a program of instructions executable by a machine to perform method steps for managing a database, said method steps comprising determining from the set of visibility rules, stored at a single location, the visibility of the user (33a, 33b, 33c) of the partially replicated database (23a, 23b, 23c) to data being propagated, and propagating said data to the partially replicated database (23a, 23b, 23c) only if the user (33a, 33b, 33c) of the partially replicated database (23a, 23b, 23c) has visibility to the data.

Inventors: BRODERSEN ROBERT S, LIM PETER S, BRODERSEN, ROBERT, S., LIM, PETER, S.
Applicants: BRODERSEN ROBERT S, LIM PETER S, SIEBEL SYSTEMS INC, BRODERSEN, ROBERT, S., LIM, PETER, S., SIEBEL SYSTEMS, INC.
Application year: 1998
Main classification: G06F17
IPC codes: G06F12, G06F17