Abstract:
The present invention increases the efficiency of dynamically, reusable computer environments by first retrieving data set information from a volume table of contents (VTOC) to ensure its consistency with the catalog. After obtaining the necessary information about the data sets, control statements are generated and appropriate programs invoked to perform the desired maintenance operations. Reinitializing and reconfiguring the reusable computer environment by starting with the VTOC prevents post-maintenance issues such as a data set with an entry in an integrated catalog facility (ICF) catalog while the data set no longer exists on a volume, a cataloged virtual storage access method (VSAM) cluster with disassociated DATA or INDEX data sets, and a data set catalog entry that has been scratched while the data set still exists on a volume. The present invention saves time and money by preventing such problems up-front instead of correcting them after-the-fact.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to data set maintenance on a mainframe computer system comprising a catalog directory structure and more particularly relates to automating volume table of contents (VTOC) driven data set maintenance. 
     2. Description of the Related Art 
     In dynamically reusable software environments, such as test environments, automated test cases reconfigure and reinitialize the contents of a direct access storage device (DASD). Data sets which have been allocated for prior test cases are removed en masse to make space for data sets required by new tests. A given test case or process does not necessarily know which test case preceded it, and does not necessarily know what the prior contents of the DASD were. Consequently, various programs are used to scratch the entire contents of a volume using a VTOC parameter, which specifies that all data sets on an indicated volume, with a few specific exceptions, are to be scratched. While this process eliminates the necessity to know the specific contents of a volume before removing them, it does not remove the entries for the scratched data sets in the various integrated catalog facility (ICF) catalogs that reference the scratched data sets. 
     Consequently, catalogs may reference data sets which no longer exist. If subsequent steps in the process try to access a data set which no longer exists, or try to validate the existence of the data set, the catalog entry which no longer reflects the actual status of the data set will cause unexpected results or errors. Consequently, automated tests may fail resulting in allocation failures, duplicate data set name errors, and a loss of productivity. 
     Presently, a maintenance operation to remove data sets allocated to a prior test case is categorized as SCRATCH VTOC type DASD maintenance because it uses the VTOC parameter of a maintenance utility to scratch the contents of the DASD. As a result of this type of maintenance, several ill favored situations can arise. For example, a data set may have an entry in an ICF catalog but no longer exist on a volume. Another example might be that a virtual storage access method (VSAM) cluster may be cataloged but the DATA or INDEX data set associated with the VSAM cluster may no longer exist on a volume. Yet another example that might occur due to maintenance, but not SCRATCH VTOC type DASD maintenance, might be that the data set exists on a volume but no longer has an entry in an ICF catalog. There are no current solutions that will prevent these problems and others from arising due to maintaining dynamically-reusable environments. Current solutions are only aimed at remedying the problems that arise due to maintenance, therefore, they can be characterized as after-the-fact remedies. 
     For example, one such remedy utilizes a program with a parameter to handle cataloging issues in order to fix data set problems. Similarly, another program used as an after-the-fact remedy includes a parameter for fixing VSAM cluster problems. Although these programs are capable of remedying most ICF catalog issues that arise after maintenance, they require substantial input from a user, who must spend time analyzing an error situation, to be capable of remedying that error situation. These programs can be used by themselves or in combination to remedy data set problems and VSAM cluster problems resulting from data set maintenance. Unfortunately, they consume valuable time and resources after the maintenance which leads to the problem. 
     Other programs are available to fix catalog problems after-the-fact. One such program is IBM&#39;s Integrated Catalog Forward Recovery Utility (ICFRU). ICFRU is a basic tool to help in a forward recovery situation. ICFRU does not offer a wide range of features, but can help for catalog recovery. Because it is a limited program, it is only beneficial under certain circumstances. One circumstance might be where the problem arises due to a data set reportedly being cataloged but not actually existing. Consequently, it would not be able to remedy all problems occurring due to data set maintenance, such as when the data set exists and is supposed to be cataloged, but is not. 
     Still other programs are capable of recovering a catalog after a disaster. Although these programs have increased the speed at which problems occurring due to maintenance are fixed, they are not capable of preventing those problems from occurring. Thus, they are a round-a-bout after-the-fact way of dealing with errors due to data set maintenance. A more efficient approach would be to prevent the errors from occurring, which would eliminate the need for after-the-fact remedies. 
     Due to the foregoing, a need exists for an apparatus, system, and method that would prevent problems from occurring due to a SCRATCH VTOC-type DASD maintenance such as a data set having an entry in an ICF catalog but no longer existing on a volume, a VSAM cluster being cataloged but the DATA or INDEX data set associated with the VSAM cluster no longer existing on a volume, or a data set existing on a volume but no longer having an entry in an ICF catalog. Beneficially, such an apparatus, system, and method would automate VTOC driven data set maintenance. 
     SUMMARY OF THE INVENTION 
     The present invention has been developed in response to the present state of the art, and in particular, in response to the problems and needs in the art that have not yet been fully solved by currently available data set maintenance resources on dynamically, reusable environments. Accordingly, the present invention has been developed to provide an apparatus, system, and method for automating VTOC driven data set maintenance that overcome many or all of the above-discussed shortcomings in the art. 
     The apparatus to automate VTOC driven data set maintenance is provided with a logic unit containing a plurality of modules configured to functionally execute the necessary steps of automating VTOC driven data set maintenance to reconfigure and reinitialize dynamically, reusable environments. These modules in the described embodiments include an information module, a determination module, an identification module, a control statement generation module, and an execution module. 
     The apparatus, in one embodiment, is configured to retrieve information about data sets residing on a volume from a volume table of contents (VTOC). The volume may be identified by an initial set of control statements. The volume may also be predetermined. The initial set of control statements facilitates determining the maintenance operations to perform on the data sets. The maintenance may include cataloging, uncataloging, or deleting data sets. By applying the information retrieved from the VTOC to the maintenance operations determined, the method may generate control statements to accomplish the desired tasks. 
     Generating control statements may include generating a variety of syntactically different control statements depending on the type of data set being maintained or the utility that will execute the control statement. Executing the control statements may include selecting the proper utility to run each control statement. The apparatus may gather information from the VTOC to ensure its consistency with the appropriate catalog. This may also prevent reconfiguration and initialization errors. Such errors include leaving an ICF catalog entry for a data set that no longer exists on a volume and leaving VSAM clusters cataloged without a DATA or INDEX data set on a volume. 
     The apparatus is further configured, in one embodiment, to selectively bypass data sets during the maintenance operations. The data sets to bypass may be indicated by parameters of the set of initial control statements. This enables certain data sets to remain constant, such as data sets required for booting the computer environment. 
     In a further embodiment, the apparatus may be configured to designate a supplemental identifier in situations where a control statement being generated requires a VSAM cluster name, but one is not available. The set of initial control statements are examined for the presence of a VSAMLLQ function. If the VSAMLLQ function is not provided or a value is not assigned to it, then a supplemental identifier is substituted and used as the association identifier. 
     A system of the present invention is also presented to automate VTOC driven data set maintenance. The system may be embodied in a mainframe computer environment or other computer environment. In particular, the system, in one embodiment, includes a computer, at least one integrated catalog facility (ICF) catalog, and a data set maintenance resource. The data set maintenance resource may include an information module, a determination module, an identification module, a control statement module, and an execution module in accordance with the present invention. 
     The system may be further configured to respond to an initial set of control statements. The data set maintenance resource may utilize the initial set of control statements to determine the maintenance operations to perform on the dynamically reusable environment of the mainframe computer. The data set maintenance resource may examine the VTOC to ensure its consistency with the appropriate catalogs. 
     A method of the present invention is also presented for automating VTOC driven data set maintenance. The method in the disclosed embodiments substantially includes the steps necessary to carry out the operations presented above with respect to the operation of the described apparatus and system. In one embodiment, the method includes retrieving information from a VTOC. The VTOC contains information regarding data sets that can be used to eliminate any potential mismatches of the volume contents and the associated catalogs. The method also may include determining the maintenance operations to perform. In one embodiment, the maintenance operations are determined based on a set of initial control statements provided by a director. 
     The method also may include identifying related data sets by using an association identifier. The association identifier may be the name of a VSAM cluster. The set of initial control statements may acquire the VSAM cluster name via a VSAMLLQ operation, which may be a parameter of the set of initial control statements. The VSAMLLQ function may extrapolate the VSAM cluster name by replacing a low-level qualifier name of the data set with a value assigned to the VSAMLLQ function. In one embodiment, the VSAMLLQ function or value might not be provided in the set of initial control statements, in this embodiment, a supplemental identifier may be substituted as the association identifier to satisfy control statement requirements. 
     The method may generate control statements to perform the maintenance operations. The maintenance operations may be different for different types of data sets. As a result, the maintenance operations may be syntactically different. In addition, the control statements may be generated to run on various programs, which might require the control statements to be syntactically different to conform to that program&#39;s requirements. 
     With the control statements generated to fulfill the desired maintenance, executing the control statements facilitates maintenance completion. In one embodiment, executing control statements includes selecting the utility to run each control statement depending on the syntax of the control statement. Similarly, executing control statements may include selecting a utility to run each control statement depending on the data set being maintained, or the maintenance operation to be performed. 
     In a further embodiment, the method includes retaining data set anonymity by first determining the contents as well as the associations of the volume from the VTOC. Additionally, by examining the VTOC first, the method eliminates any potential mismatches of the volume contents with the catalogs introduced by maintenance performed on the volume. The volume to be maintained may be identified by the set of initial control statements. Likewise, the set of initial control statements may identify data sets to bypass for maintenance. 
     Reference throughout this specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the present invention should be or are in any single embodiment of the invention. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention. Thus, discussion of the features and advantages, and similar language, throughout this specification may, but do not necessarily, refer to the same embodiment. 
     Furthermore, the described features, advantages, and characteristics of the invention may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize that the invention may be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the invention. 
     These features and advantages of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order that the advantages of the invention will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which: 
         FIG. 1  is a schematic block diagram illustrating one embodiment of a mainframe computer system for automating VTOC driven data set maintenance in accordance with the present invention; 
         FIG. 2  is a schematic block diagram illustrating one embodiment of a data set maintenance resource and integrated catalog facility (ICF) in accordance with the present invention; 
         FIG. 3  is a schematic flow chart diagram illustrating one embodiment of a method for automating VTOC driven data set maintenance in accordance with the present invention; 
         FIG. 4  is a schematic flow chart diagram illustrating one embodiment of a method for retrieving data set information in accordance with the present invention; 
         FIG. 5  is a schematic flow chart diagram illustrating one embodiment of a method for generating control statements in accordance with the present invention; and 
         FIG. 6  is a schematic flow chart diagram illustrating one embodiment of a method for generating and executing control statements in accordance with the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Many of the functional units described in this specification have been labeled as modules, in order to more particularly emphasize their implementation independence. For example, a module may be implemented as a hardware circuit comprising custom VLSI circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. A module may also be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices or the like. 
     Modules may also be implemented in software for execution by various types of processors. An identified module of executable code may, for instance, comprise one or more physical or logical blocks of computer instructions which may, for instance, be organized as an object, procedure, or function. Nevertheless, the executables of an identified module need not be physically located together, but may comprise disparate instructions stored in different locations which, when joined logically together, comprise the module and achieve the stated purpose for the module. 
     Indeed, a module of executable code may be a single instruction, or many instructions, and may even be distributed over several different code segments, among different programs, and across several memory devices. Similarly, operational data may be identified and illustrated herein within modules, and may be embodied in any suitable form and organized within any suitable type of data structure. The operational data may be collected as a single data set, or may be distributed over different locations including over different storage devices, and may exist, at least partially, merely as electronic signals on a system or network. 
     Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment. 
     Reference to a computer readable storage medium may take any form capable of causing execution of a program of machine-readable instructions on a digital processing apparatus. A computer readable storage medium may be embodied by a compact disk, digital-video disk, a magnetic tape, a Bernoulli drive, a magnetic disk, a punch card, flash memory, integrated circuits, or other computer readable storage medium. 
     Furthermore, the described features, structures, or characteristics of the invention may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided, such as examples of programming, software modules, user selections, network transactions, database queries, database structures, hardware modules, hardware circuits, hardware chips, etc., to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention. 
       FIG. 1  depicts one embodiment of a mainframe computer system for automating volume table of contents (VTOC) driven data set maintenance in accordance with the present invention. The mainframe computer system  100  includes a mainframe computer  110 , a system bus  120 , a central processing unit (CPU)  122 , a random access memory (RAM)  124 , a network interface card (NIC)  126 , input/output (I/O) devices  128 , a network  130 , a router  132 , a computer  134 , a switch  136 , the Internet  138 , a direct access storage device (DASD)  140 , a data set maintenance resource  150 , an integrated catalog facility (ICF) catalog  160 , and one or more volumes  170 . The depicted mainframe computer system  100  is one embodiment for automating VTOC driven data path redundancy. 
     The depicted mainframe computer  110  houses the system bus  120 . The system bus  120  may provide a communication link among components within the mainframe computer  110  such as the CPU  122 , the RAM  124 , the NIC  126 , and the DASD  140 . In one embodiment, the CPU processes and transmits data received over the system bus  120  from and to components connected to the system bus  120 . The system bus  120  may provide a communication link to peripheral devices such as I/O devices  128 . 
     The I/O devices  128  may communicate with the mainframe computer  110  via the system bus  120 . The I/O devices  128  may provide a communication channel from the mainframe computer  110  to a user. Each I/O device  128  may individually include a monitor, a keyboard, a mouse, or the like. 
     The network interface card  126  may communicate with devices external to the mainframe computer  110  via the network  130 . In one embodiment, the network interface card  126  provides a communication link between the system bus  120  and the network  130 , thus allowing the mainframe computer  110  to communicate with devices on the network  130 . Such devices may comprise the computer  134 , the switch  136 , or the router  132 . The computer  134  may be another mainframe computer  110 , a workstation, a server, or the like. The router  124  may have a connection from the network  130  to the Internet  138 . 
     The depicted DASD  140  may reside as a component in the mainframe computer  110 . In one embodiment, the DASD  140  stores part of the data set maintenance resource  150 . In the depicted embodiment, the data set maintenance resource  150  is housed entirely within the DASD  140 . The DASD  140  may also store part of the ICF catalog  160 . In the depicted embodiment, the ICF catalog  160  is housed entirely within the DASD  140 . The ICF catalog  160  may comprise volumes  170 . Volumes  170  may comprise data regarding data sets (i.e., metadata) as well the data sets themselves. 
     The ICF catalog  160  stores information about other data sets. In one embodiment, the ICF catalog  160  is a data set storing information about other data sets. This information may include data set attributes as well as data set locations to facilitate retrieving a desired data set only by name without requiring a user to specify the data set&#39;s location. 
       FIG. 2  depicts one embodiment of a DASD environment comprising a data set maintenance resource and an integrated catalog facility (ICF) catalog in accordance with the present invention. The DASD environment  200  includes a data set maintenance resource  210 , an information module  212 , a determination module  214 , an identification module  216 , a generation module  218 , an execution module  220 , an integrated catalog facility (ICF) catalog  230 , a volume  240 , a volume table of contents (VTOC)  242 , a VSAM volume data set (VVDS)  244 , data sets  246 , a volume  250 , and a basic catalog structure (BCS)  252 . The depicted DASD environment  200  is one embodiment for automating VTOC driven data set maintenance. 
     In the depicted embodiment, the data set maintenance resource  210  includes the information module  212 , the determination module  214 , the identification module  216 , the generation module  218 , and the execution module  220 . The data set maintenance resource  210  may execute the preceding modules. In one embodiment, the data set maintenance resource  210  receives control statements from a director. A director may be a person, process, or application configured to provide a set of control statements. Control statements are a set of commands for the computer system. One example of control statements are Job Control Language (JCL) control statements. These statements identify the user, indicate what processes are to be run, what resources are required, and what priority to allocate to the job. 
     The information module  212  may retrieve information regarding data sets  246  on a volume  240  from the VTOC  242 . The information retrieved by the information module  212  may include identification of one or more designated volumes. In one embodiment, control statements from the director are examined by the information module  212  to identify the designated volume. Control statements may be used to identify a function to be performed by a selected program or utility. Control statements may also be used to identify specific volumes or data sets to be maintained or processed. 
     Other information retrieved by the information module may include a data set name, catalog status, the type entry in the catalog such as the type of data set or the VSAM index of a VSAM data set, or associated data set names if applicable. The information retrieved may further include identification of data sets to bypass during the maintenance. 
     In one embodiment, data set anonymity is retained by first determining the contents as well as the associations of the volume from the VTOC  242 . Data set anonymity means keeping the information identifying a data set anonymous by referencing other sources to acquire information about the data set as opposed to the data set itself. Data set anonymity is advantageous for the user because numerous data set names needs not be memorized or otherwise tracked. Any necessary identification of the data set is discovered via the VTOC  242 , and further discovered via the VVDS  244 , and may be even further discovered via the BCS  252 . By examining the VTOC  242  first, the method may also eliminate any potential mismatches of the volume contents with the catalogs introduced by maintenance performed on the volume because the VTOC  242  includes information regarding VSAM data set associations. 
     In one embodiment, the information module  212  runs an IEHMAP utility to read the VTOC  242 . IEHMAP is a utility that will analyze a volume and print a report showing the exact location of each extent of all the data sets on the volume. The IEHMAP utility may generate a report of the contents of the VTOC  242 . In this embodiment, the information module  212  passes IEHMAP the initial control statements generated by the director and IEHMAP identifies the volumes  240  and  250  to perform maintenance on based on those control statements. The information obtained from the information module  212  may be gathered in a report where information may be extracted. 
     In the depicted embodiment, the determination module  214  determines one or more maintenance operations to perform. The determination module  214  may examine control statements received from a director to determine the one or more maintenance operations to perform. The determination module  214  may use the information obtained from the information module  212  for further determination in the data set maintenance resource  210 . The determination module  214  may use the information obtained from the initial control statements received from a director for further determination in the data set maintenance resource  210 . 
     The identification module  216  may identify related data sets by using an association identifier. The association identifier may be included with the information retrieved from the information module  212 . The association identifier may be a name of a cluster of data sets. In one embodiment, the association identifier is required to perform maintenance on the data sets. In this embodiment, if the cluster name is not provided by the information module  212 , then the information module  212  substitutes a supplemental identifier as the association identifier so the maintenance can proceed. The supplemental identifier may be a null value. In one embodiment, the supplemental identifier is a predetermined value capable of being incremented to prevent mismatching associations. 
     In one embodiment, the generation module  218  generates one or more control statements for performing one or more maintenance operations on the data sets  246 . The control statements may be run by a plurality of utilities which require syntactically different control statements; in this situation, the control statements must be generated to be executed by a selected utility. The type of data set being maintained may determine the utility to generate control statements for. In one embodiment, the determination module  214  determines what maintenance operations to perform on the data sets  246 . The generation module  218  may generate control statements based on the determination of the maintenance to perform by the determination module  214 . 
     The execution module  220  executes the one or more generated control statements to perform maintenance on the data sets  246 . In one embodiment, the execution module  220  selects a utility to execute the generated control statement with. Selecting a utility may be based on the type of data set to be processed. In another embodiment, selecting a utility is based on the syntax of the control statement. 
     One utility that may be used by the execution module  220  is IDCAMS. IDCAMS is a utility used to create, delete, rename, catalog, or uncatalog data sets. IDCAMS may also be used to manage catalogs. Another utility that may be used by the execution module  220  is IEHPROGM. IEHPROGM is a utility that provides facilities for deleting or renaming data sets and for cataloging or uncataloging non-VSAM data sets. The execution module  220  may not be limited to using just IDCAMS or IEHPROGM. In one embodiment, the execution module  220  uses any utility capable of performing the desired maintenance. 
     The ICF catalog  230  may include the volumes  240  and  250 . In the depicted embodiment, volume  240  includes the VTOC  242 , the VSAM volume data set (VVDS)  244  and the data sets  246 . Also in the depicted embodiment, volume  250  includes the basic catalog structure (BCS)  252 . In the depicted embodiment, both the ICF catalog  230  and the data set maintenance resource  210  reside on the DASD  140 . The data set maintenance resource  210  may act on the ICF catalog  230  and its components to automate VTOC driven data set maintenance. 
     In a preferred embodiment, the data set maintenance resource  210  utilizes the VTOC  242  to obtain information about volume  240  and data sets  246 . The VTOC  242  may store certain information regarding data sets such as data set attributes and a description, which may include size, location, and permissions. The VVDS  244  may also be used by the data set maintenance resource  210  to obtain information regarding data sets  246 . 
     Data sets  246  are collections of logically related data records. Data sets  246  may include both VSAM and non-VSAM data sets. VSAM is an IBM (International Business Machines) disk file storage scheme used in mainframe computer operating systems. The VSAM storage scheme has been implemented throughout operating systems utilizing the MVS (Multiple Virtual Storage) architecture. The MVS architecture originated in the MVS 24-bit IBM operating system, which has evolved into the present z/OS 64-bit IBM operating system. 
     The VVDS  244  may be considered an extension of the VTOC  242 . The VVDS  244  may store information about VSAM and non-VSAM data sets. Information not stored in the VTOC  242  may be stored in the VVDS  244  such as VSAM data set attributes, VSAM data set catalog name, and non-VSAM data set catalog name. 
     The BCS  252  may also be used by the data set maintenance resource  210  to obtain information regarding data sets  246 . The information that may be stored on the BCS  252  is a volume the data set resides on, a data set type, a data set association, and ownership of the data set. In one embodiment, the BCS  252  points to multiple VSAM Volume Data Sets and, consequently, to multiple Volume Table Of Contents; the relationship between the BCS  252 , VVDS  244 , and VTOC  242  is not exclusive. 
     The schematic flow chart diagrams that follow are generally set forth as logical flow chart diagrams. As such, the depicted order and labeled steps are indicative of one embodiment of the presented method. Other steps and methods may be conceived that are equivalent in function, logic, or effect to one or more steps, or portions thereof, of the illustrated method. Additionally, the format and symbols employed are provided to explain the logical steps of the method and are understood not to limit the scope of the method. Although various arrow types and line types may be employed in the flow chart diagrams, they are understood not to limit the scope of the corresponding method. Indeed, some arrows or other connectors may be used to indicate only the logical flow of the method. For instance, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of the depicted method. Additionally, the order in which a particular method occurs may or may not strictly adhere to the order of the corresponding steps shown. 
       FIG. 3  depicts one method for automating VTOC driven data set maintenance in accordance with the present invention. The method  300  includes retrieving  310  data set information, determining  320  one or more maintenance operations, identifying  330  associations, generating  340  one or more control statements, and executing  350  the control statements. The method  300  facilitates automating VTOC driven data set maintenance in accordance with the present invention. 
     Retrieving  310  data set information may include retrieving identifying information from an initial set of control statements indicating a volume from which to retrieve the data set information. The data set information may be obtained using a program such as IEHMAP to generate a report about a volume&#39;s VTOC. In one embodiment, the information is retrieved from the VTOC before any maintenance occurs. 
     Additional data set information may also be retrieved from a VVDS and a BCS. The information may include a data set name, a catalog status, a type entry in the catalog such as a type of data set or a VSAM index of a VSAM data set, or associated data set names if applicable. Retrieving  310  data set information may further include identifying data sets to bypass during the maintenance. 
     Determining  320  one or more maintenance operations to perform may include extracting the maintenance operations from a set of initial control statements. The maintenance operations may include cataloging uncataloged data sets, uncataloging cataloged data sets, and deleting either uncataloged or cataloged data sets. 
     Identifying  330  associations may include examining the information retrieved to obtain an association identifier that is common to the association or cluster, also called a cluster name. Identifying  330  associations may prevent alienating data sets during maintenance. In one embodiment, an association identifier may not be provided in the retrieving operation  310 , but might be required as a parameter of a control statement. In this embodiment, the retrieving operation  310  may substitute a supplemental identifier as the association identifier, so that the identifying operation  330  may obtain the association identifier. 
     Generating  340  one or more control statements may include generating control statements designed to perform a required maintenance. In one embodiment, a plurality of programs are capable of running control statements, however, the programs might require syntactically different control statements. In this embodiment, the control statements must be generated for execution by a specific program. The type of data sets being maintained may determine the program selected to execute the control statement. In one embodiment, determining  320  one or more maintenance operations is directly related to generating  340  one or more control statements because the type of maintenance determines what program will execute the control statements. 
     Executing  350  the control statements may include selecting the appropriate program to execute the generated control statements. In one embodiment, the program is selected based on the data sets being maintained. In another embodiment, the program is selected based on the type of maintenance to perform. In yet another embodiment, the program is selected based on the generated control statements. The generated  340  control statements may be generated for execution by different programs; therefore, the executing operation  350  may include selecting multiple programs to execute different control statements. 
       FIG. 4  depicts one method for retrieving data set information in accordance with the present invention. The method  400  includes mapping  410  the VTOC, searching  420  data set information, deciding  430  if the data set is cataloged, determining  440  the data set type entry, deciding  450  if the data set has associations, and determining  460  data set associations. The method  400  facilitates retrieving data set information as part of automating VTOC driven data set maintenance. 
     Mapping  410  the VTOC may be completed before any maintenance operations are performed. Mapping  410  the VTOC may generate a report listing the data sets on the volume. In one embodiment, mapping  410  the VTOC is accomplished by running the IEHMAP program. The report generated may contain extractable data regarding the data sets on the volume. The data may comprise a data set name, a volume identifier, and a data set organization. The data set organization may include whether the data set is VSAM and whether it is sequential or partitioned. 
     Searching  420  data set information may include receiving data from the report generated by mapping  410  the VTOC. Each data set in the report may be searched. Searching  420  the data set information may require receiving the data set name. Searching  420  the data set information may require receiving an indicator that associations are requested, the cluster name may be supplied as the associated data set names. In one embodiment, searching  420  the data set information indicates whether the data set is cataloged. If the data set is cataloged, additional information may include an indication of the type of data set and associated data set names for VSAM data sets. 
     In one embodiment, searching  420  the data set information is accomplished through a catalog search interface (CSI) module such as the IGGCSI00 program. Searching  420  the data set information provides information necessary for deciding  430  if the data set is cataloged. If the data set is not cataloged, then further information may not be required because the data set name and catalog status are known. If the data set is not cataloged, then deciding  465  if there are more data sets to search may either end the method at step  470  or continue the method by searching  420  the next data set&#39;s information. 
     If the data set is cataloged, then further information regarding the data set may be obtained. For example, receiving further information may require determining  440  the data set type entry in the catalog. In one embodiment, the data set type entry in the catalog includes the type of data set. If the data set is a VSAM type data set, then the data set type entry in the catalog may also include a VSAM index data set and a VSAM data set. Deciding  450  if the data set is associated may include identifying what type of data set the data set is. 
     If the data set is non-VSAM, then there are no associations and deciding  465  if there are more data sets to search may either end the method at step  470  or continue the method by searching  420  the next data set&#39;s information. If the data set is VSAM, then the information included in determining  440  the data set type entry includes the VSAM index and associated data set names. Determining  460  data set associations may include reading the information obtained from determining  440  the data set type entry to obtain the data set associations. 
       FIG. 5  depicts one method for generating control statements in accordance with the present invention. The method  500  includes determining  510  one or more maintenance operations, deciding  520  if a cluster name is required, deciding  530  if the cluster name is provided, designating  540  a supplemental identifier, retrieving  550  the cluster name, and generating  560  one or more control statements. The method  500  facilitates generating control statements in accordance with the present invention. 
     Determining  510  one or more maintenance operations may include identifying what syntax a control statement requires. In one embodiment, determining  510  one or more maintenance operations identifies whether a cluster name will be required for the control statement to execute properly. Deciding  520  if the cluster name is required may depend on the operation the control statement will perform as part of the maintenance. If deciding  520  that the cluster name is not required then the method proceeds by generating  560  one or more control statements. 
     If deciding  520  determines that the cluster name is required, then initial control statements provided by a director may be examined. The initial control statements provided by a director may include a function to identify a low-level qualifier for VSAM data sets; the function may be VSAMLLQ. The VSAMLLQ function may be used to extrapolate a VSAM cluster name by replacing the low-level qualifier name of the data set with the VSAMLLQ value. Deciding  530  whether the cluster name is provided may include determining if the VSAMLLQ function is present and assigned a value. 
     If the VSAMLLQ function is present and provided with a value, then retrieving  550  the cluster name may include replacing the low-level qualifier name of the data set with the VSAMLLQ function value. If the VSAMLLQ function is not provided with a value or not present, then the low-level qualifier name of the data set may be replaced by a supplemental identifier acting as the cluster name. Once the cluster name is acquired either by retrieving  550  the cluster name or by designating  540  a supplemental identifier, generating  560  one or more control statements may include incorporating the cluster name into the control statement that requires it. One or more control statements may be generated regarding a data set and not all of the control statements may require the cluster name. 
       FIG. 6  depicts one method for generating and executing control statements in accordance with the present invention. The method  600  includes determining  610  the maintenance category, determining  620  the data set properties, generating  630  one or more control statements, and invoking  640  the program to execute the control statements. The method  600  facilitates generating and executing control statements in accordance with the present invention. 
     Determining  610  the maintenance category includes identifying what type of maintenance to perform on the data sets. In one embodiment, the maintenance is deleting cataloged data sets. In another embodiment, the maintenance is deleting uncataloged data sets. The maintenance might include uncataloging cataloged data sets. Similarly, the maintenance might include cataloging uncataloged data sets. In one embodiment, the maintenance includes one or more of the preceding actions. Determining  610  the maintenance category might include examining initial control statements to identify what type of maintenance to perform. 
     Once the maintenance category has been determined, determining  620  the data set properties is required. Determining  620  the data set properties includes identifying information regarding the data set. This information might help to facilitate generating  630  one or more control statements. The data set properties might include a data set name, a data set catalog status, a data set type, a data set type entry in the catalog if applicable, and a data set&#39;s associations if applicable. 
     Determining  620  the data set properties might include executing a program to retrieve a list of data sets from the VTOC. Such a program might be IEHMAP or the like. Determining  620  the data set properties might include executing a search program to search each data set listed in the VTOC and to retrieve the identified information regarding each data set. Such a program might be the IGGCSI00 module of IBM&#39;s catalog search interface (CSI) or the like, which programs retrieve catalog data. 
     Generating  630  one or more control statements may utilize the maintenance category determined in conjunction with the data set properties determined to generate applicable control statements. Generating  630  one or more control statements may include generating syntactically different control statements depending on the type of data set being maintained. In one embodiment, generating  630  one or more control statements includes generating syntactically different control statements depending on the program that will be used to execute the control statement. Generating  630  one or more control statements may include generating multiple control statements for one data set depending on the type of maintenance category determined  630 . 
     Invoking  640  a program to execute the control statements may include examining the syntax of the control statement to identify what program to invoke. In one embodiment, invoking  640  a program to execute control statements includes invoking multiple programs to execute a set of control statements. Such programs may include IDCAMS, IEHPROGM, or the like. In another embodiment, invoking  640  a program to execute control statements includes invoking only one program to execute a set of control statements. 
     The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.