WitVLd iVVil lhe SECTION 1 IDR3709 Approved For Release 2002/05/17 : CIA-RDP96-00788R001300240001-2 e Write simple command sequences (procedures) that can be per formed repeatedly. @ Write reports to format data output. @ Delete data froma file. @ Add new records to a file. Files Created by POWER Most users of POWER will not need to worry about file types and structures; POWER takes care of file-related details for you. However, some users will need to know about the files POWER creates. The most commonly encountered files in the POWER system are called MIDAS, (Multiple Index Data Access Systems) files. MIDAS files: MIDAS files are special data files structured for quick data retrieval. POWER can access these files using a ‘direct’ retrieval method. Each MIDAS file has an associated index subfile, which serves as a quick look-up file (much like a phone book). All the search descriptors you've defined for the file are listed in the subfile along with their 'address' locations in the file. When you specify a descriptor to be searched on during a file query, POWER goes to the index subfile, looks up the descriptor and its address, goes to the data file and retrieves the proper records. This kind of search can be called the index access method. Other files: Files of other types, such as ASCII sequential, may be created or overlaid in POWER. Sequential files are set up quite differently from MIDAS files. There is no index subfile for sequential files; therefore, all descriptor values must be searched for sequentially in the file instead of directly. Sequential searching involves stepping through every record in the file, one after the other, in the order in which they are physically located in the file, until the desired one is found. When a descriptor is specified in a search expression, POWER goes directly to the file and searches every record until the proper descriptor (key) value is located. The sequential access method can take a lot more time than the index access method, especially if the file contains many records. Display Descriptors vs. Search Descriptors In MIDAS files, a descriptor defined as a display descriptor does not appear in the index subfile. When you search on a display descriptor, POWER must do a sequential search through the actual MIDAS file until the desired field value for the descriptor is found. In other words, for MIDAS files, search descriptors are accessed by the index access method; display descriptors, by the sequential access method. REV. @ 1 105 g Approved For Release ING LAS TED cen001200240001-2
= Approved For Release 2002/05/17 : CIA-RDP96-00788R001300240001-2 In sequential files, display descriptors are accessed sequentially, just as search descriptors are; however, they are usually reserved for fields not often searched on. The reasons for having both search am display descriptors are simple: @ You can define only 20 search descriptors per file (only 14 if you select the TEXT and KEYWORD option in POWER+); if you want more keys to search on, they must be defined as display descriptors. e Search descriptors have a maximum length of 32 characters; Display descriptors have a maximum length of 88 characters. e Display descriptors are usually the fields you won't search on frequently. e In both POWER and POWER+, having display descriptors enables you to define up to 512 fields per record, instead of just 20. CONVENT IONS Throughout this manual, many symbols and conventions are used in describing command formats ami syntax. There are also some special rules for defining descriptor nanes and file names in POWER. These conventions are listed below. Command Syntax Rules All POWER command formats are governed by the following syntax rules: @ WORDS-IN-UPPER-CASE Capital letters identify command words or keywords. They are to be entered literally. If a portion of an upper-case word is underlined, the underlined letters indicate the minimum legal abbreviation. e Words-in-lower-case Lower case letters identify parameters. The user substitutes an appropriate numerical or text value. e Braces { } Braces indicate a choice of parameters and/or keywords. At least one choice must be selected. @ Brackets [ ] Brackets indicate that the word or parameter enclosed is optional. 1 106 9 June 1979 Approved For Release EINE LA SS PEt fel zseR001 300240001-2
SECTION 1 UNCkASel FIED Approved For Release 2002/05/17 : CIA-RDP96-00788R001300240001-2 @ Hyphen - A hyphen identifies a command line option, as in: SPOOL -LIST @ Parentheses ( ) When parentheses appear in a command format, they must be included literally. @ Ellipsis ... The preceding parameter may be repeated. @ option The word option indicates one or more keywords or parameters can be given, and that a list of options for the particular command follows. Command Format The general format of many POWER commands is given below. Commands are im uppercase: lowercase words are ‘arguments’, or ‘'parameters'. Arguments are usually optional on a command line and can be any one of several values, depending on the context in which the comnand is being used. ie variable COMMAND [Snn]{ descriptor-name {‘vatve KW variable Snn Set number where nn is a number from 1] to 49. descriptor-name A specific descriptor name used in various search and display commands. KW Indicates that a keyword value is to be searched on or displayed. "value' Actual record value corresponding to the descriptor, variable or keyword named previously. Must be enclosed in single quotes. variable A numeric or character variable used in search or canputation expressions. REV. @ 1 107 yg Approved For reieact  OLASSIELED, srssroo: 300240001-2
UNCEASSIFIED INTRODUCTION Approved For Release 2002/05/17 : CIA-RDP96-00788R001300240001-2 Same POWER commands accept one or more options from a list. These are represented as follows: COMMAND option-1] option-2 option-n If more than one option is specified on a command line, they are separated by commas or spaces, aS indicated in each individual command format. Special Characters Several characters reserved for special included in descriptor names or file names. are: -=AAW 1 +t mas * period comma left parenthesis right parenthesis slash asterisk plus minus equal greater than less than single quote uses by POWER cannot be These special characters The only characters listed above which can be used in defining file names are: period (.) and minus (-). 1 108 ll June 1979 Approved For aeeaaeo NG, SIFTED cozootsoo2s000
Approved For Release 2002ada RiEAbpss-o07ssR001 300240001-2 Appendix B A TENTATIVE RV ASSESSMENT SHEET SECRET Approved For Release 2002/05/17 : CIA-RDP96-00788R001300240001-2