ADABAS

ADABASObjectives The objective of this presentation is  To get in depth knowledge on ADABAS (Adaptable Data Base System).  Identify advantages and disadvantages of ADABAS.  How to do an efficient programming with ADABAS.  To get knowledge of ADABAS nucleus , ADABAS Calls and Utilities.  Cobol-Adabas programming using ADASQL.  Use of direct calls to access ADABAS. Learning Outcome At the end of this course, you are expected to  To use ADABAS database efficiently in your program.  To do programming by using cobol with adabas.  Indepth knowledge of ADASQL. Adabas (Adaptable Database)  Pseudo-Relational DBMS  4 Components  NUCLEUS  ADABAS ASSOCIATOR  INVERTED LIST  ADABAS CONVERTER  DATA STORAGE  WORK DATASET Additional datasets can be incorporated into the operating environment to maintain The images of changes to the database and an audit of all commands processed during the Session.  PROTECTION LOG  COMMAND LOG ASSOCIATOR :  The first of the three required data sets is the associator which contains information about the data base in general and specific information about individual files. DATA STORAGE :  The data storage data set,the second component of an ADABAS session,contains the actual data without chaining or pointers and no fixed or pre-defined parent-child relationships , just basic data stored for subsequent access . WORK DATA SET :  The work dataset is used by the nucleus (and applications in certain circumstances) as temporary storage for processing large lists of records sorting,error recovery and working storage. PROTECTION LOG :  The protection log contains all the before and after images necessary for ADABAS’s maintenance of the integrity of the database:back out , recovery and regeneration of corrupted data. COMMAND LOG :  The optional command log contains information useful for audit trails as well as performance monitoring. Data Storage : ADABAS Controls and maintains data in physical blocks within data storage. Each physical block is automatically assign a Relative ADABAS block number (RABN) ADABAS BLOCK LAYOUT ADABAS RECORD LAYOUT IN STORAGE INCLUSIVE BLOCK LENGTH REC-1 REC-2 REC-N FREE SPACE PADDING AREA INCLUSIVE RECORD LENGTH ISN FIELD-1 FIELD-2 FIELD-3 DATA COMPRESSION NORMAL COMPRESSION :  The ADABAS default for compression of data is Normal Compression. - Trailing blanks are removed from alphanumeric field - Leading zeros are removed from numeric field values and the data is being packed before being stored. - Packed data is stored as it is. FIXED FORMAT :  This is termed as ‘Negative Compression’ - If a field which is always filled with non-zero or non-blank data would require one extra byte for the length .In such cases a designer may specify that a field is to be stored in Fixed Format (FI) to have the field always stored as its full length without the length byte. NULL SUPRESSION - A null suppression option (NU) , the designer can achieve even greater space savings.A null suppressed field which contains blanks or zeros will be stored as one ‘empty field’ byte.Contiguous empty fields upto 63 will be compressed into a one byte ‘empty field count’. MULTIPLE VALUE (MU) FIELDS : An elementary field that occurs multiple times,is called a Multiple Value Field in ADABAS. PERIODIC GROUP (PE) : When a group of fields that occurs multiple times is called a Periodic Group in ADABAS Note :  PE Can have 99 occurrences and MU can have 191 occurrences.  As defined by adabas , a periodic group can not be defined within a periodic group but can have multiple value fields . 3GL RECORD LAYOUT : 01 CUSTOMER-RECORD. 02 CUSTOMER-NUMBER PIC 9(07). 02 SHIPPING-ADDRESS OCCURS 4 TIMES PIC X(25). 02 ORDER-NUMBER PIC 9(07). 02 LINE-ITEMS OCCURS 99 TIMES. 03 LINE-NUMBER PIC 9(03). 03 PART-ID PIC 9(07). 03 DESCRIPTION OCCURS 10 TIMES PIC X(20). 03 QUANTITY PIC 9(03). 03 UNIT-COST PIC 9(03)V99. ADABAS RECORD LAYOUT : TY L DB NAME F LENG S D REMAR ------ ---- ----------------------------------------------------------------------- - --------- - - ------------ 1 AA CUSTOMER-NUMBER N 7.0 N D M 1 AB SHIPPING-ADDRESS A 25 N 1 AC ORDER-NUMBER N 7.0 N D P 1 AD LINE-ITEM 2 AE LINE-NUMBER N 3 2 AF PART-ID N 7.0 N D M 2 AG DESCRIPTION A 20 N 2 AH QUANTITY N 3 N 2 AJ UNIT-COST N 3.2 N Adabas (Adaptable Database) ADABAS INVERTED LIST : Normal indexes contain the information necessary for ADABAS to locate all records Which have a given value in a given field.There is one normal index for each Descriptor,Superdescriptor and Hyperdescriptor defined for a file.A normal index is Often referred to as an ‘INVERTED LIST’ in ADABAS. Within each normal index , there is a single entry for each value of the descriptor .This Entry contains the compressed value of the descriptor (field) preceded by a one-byte inclusive length of this compressed value. Descriptor value count ISNs American motor 3 6,13,34 fiat 8 23,27,35,49 ford 29 2,11,54,55…… opel 2 22,32 ADABAS ADDRESS CONVERTER : The address Converter for each ADABAS file is a simple table ,indexed by ISN,It contains the relative ADABAS block number ,or RABN , of the corresponding Adabas block where the record having that ISN is stored . DATA STORAGE : The data storage data set,the second component of an ADABAS session,contains the actual data without chaining or pointers and no fixed or pre-defined parent-child relationships , just basic data stored for subsequent access . ADABAS DESCRIPTORS : DESCRIPTORS : A field can be selected as descriptor for identifying records in adabas files. UNIQUE DESCRIPTOR : It is a key that may contain one and only one occurrence of a value.ADABAS provides this capability with a single field descriptor and will not allow addition of a record with a value currently maintained in the field . SUBDESCRIPTOR : Subdescriptors are descriptors which are defined from a portion of a field.They are most useful where one wishes to provide a browse capability on long fields. SUPERDESCRIPTOR : Superdescriptors are descriptors which are made up from concatenating 2 to 5 fields. PHONETIC DESCRIPTORS : Phonetic descriptors are field values passed through an algorithm that establishes a phonetic equivalent value for ease of search ADABAS NUCLEUS : The major facility of a ADABAS NUCLEUS includes  the application interface  multi-threading  request queuing  holding records pending update  buffers  backout and recovery  common ADABAS commands The important buffers associated with ADABAS are :  Control Block  Search Buffer  Value Buffer  Format Buffer  Record Buffer  ISN Buffer CONTROL BLOCK Contains Command ID ,Database and File Ids, Return-Code…. SEARCH BUFFER Descriptor Ids for retrieval requests and boolean relationships needed. VALUE BUFFER Value specifications (ranges,lists..) for retrieval requests. FORMAT BUFFER List of Ids and formats of the fields transferred. RECORD BUFFER List of values of the fields transferred ISN Buffer List of ISNs resulting from a successful FIND operation. HOLD QUEUE : To ensure data integrity it is important that two users are not able to update one record simultaneously.Therefore.When a record is read with the intention of updating or deleting it, the ISN is placed in the HOLD QUEUE along with information necessary to identify its temporary owner . DATA DEFINATION MODULE (DDM) : To access a database file by NATURAL, a logical definition of the physical database file is required. Such a logical file definition is called a DDM (data definition module). The DDM contains information about the individual fields of the file - information which is relevant for the use of these fields in a Natural program.  Thus a DDM constitutes a logical view of a physical database file.  For each physical file of a database, one or more DDMs can be defined.  DDMs are defined by the Natural administrator with Predict.  For each database field, a DDM contains : The database-internal field name. — "External" field name, that is, the name of the field as used in a Natural program. — The formats and lengths of the field — As well as various specifications that are used when the fields are output with a DISPLAY or WRITE statement (column headings, edit masks, etc.).  The Data Dictionary field definitions should match the FDT field definitions.  If these do not match then there is a danger to data integrity. ADABAS COMMANDS : READ COMMANDS : L1 / L4 READ BY ISN L2 / L5 READ IN PHYSICAL SEQUENCE L3 /L6 READ IN LOGICAL SEQUENCE L9 READ ASSOCIATOR (HISTOGRAM) FIND COMMANDS : S1 / S4 FIND ISNs S2 FIND and SORT ISNs DATA MODIFICATION COMMANDS : A1 UPDATE DATABASE FIELDS N1 / N2 ADD DATABASE RECORD WITH FIELD E1 DELETE RECORD LOGICAL TRANSACTION PROCESSING : ET END OF TRANSACTION BT BACKOUT TRANSACTION ADABAS utilities : Unload (ADAULD) ADAULD is used to unload a file in compressed format .Various options allow for the unload to take place based on a specific descriptor field or other sorts on data Dump and Restore (ADASAV) : The backup/restore utility , ADASAV,is used to dump the database or selected files and restore the same. Reorder Associator & Data Storage (ADAORD) : ADAORD is the utility used to reorder the Associator . Regenerate and Backout (ADARES) : ADARES is the utility for restarting applications,backing out data by application,user and even to time frames and/or regenerating transactions when added. INTRODUCTION TO DIRECT CALLS : Communication with ADABAS from 3GL programs is accomplished through direct calls.The primary block of code used to effect this interface is the CALL ADABAS USING Statement coded in each application program.This call will contain all necessary parameters and options to search,read,modify and write data to and from the data base.Its syntax and component are : CALL ‘ADABAS’ USING CONTROL-BLOCK, FORMAT-BUFFER, RECORD-BUFFER, SEARCH-BUFFER, VALUE-BUFFER, ISN-BUFFER. Declaration should be included for above mentioned buffers in working-storage section. For ADABAS CONTROL BLOCK : 1 CONTROL-BLOCK. 02 FILLER PIC X(2) VALUE SPACES. 02 COMMAND-CODE PIC X(2) VALUE SPACES. 02 COMMAND-ID PIC X(4) VALUE SPACES. 02 FILE-NUMBER PIC S9(4) COMP VALUE +0. 02 RESPONSE-CODE PIC S9(4) COMP VALUE +0. 02 ISN PIC S9(8) COMP VALUE +0. 02 ISN-LOWER-LIMIT PIC S9(8) COMP VALUE +0. 02 ISN-QUANTITY PIC S9(8) COMP VALUE +0. 02 FORMAT-BUFFER-LENGTH PIC S9(4) COMP VALUE +80. 02 RECORD-BUFFER-LENGTH PIC S9(4) COMP VALUE +80. 02 SEARCH-BUFFER-LENGTH PIC S9(4) COMP VALUE +80. 02 VALUE-BUFFER-LENGTH PIC S9(4) COMP VALUE +80. 02 ISN-BUFFER-LENGTH PIC S9(4) COMP VALUE +80. 02 COMMAND-OPTION-1 PIC X VALUE SPACES. 02 COMMAND-OPTION-2 PIC X VALUE SPACES. 02 ADDITIONS-1 PIC X(8) VALUE SPACES. 02 ADDITIONS-2 PIC X(4) VALUE SPACES. 02 ADDITIONS-3 PIC X(8) VALUE SPACES. 02 ADDITIONS-4 PIC X(8) VALUE SPACES. 02 ADDITIONS-5 PIC X(8) VALUE SPACES. 02 COMMAND-TIME PIC S9(8) COMP VALUE +0. 02 FILLER PIC X(4) VALUE SPACES. For User Buffers : 01 FORMAT-BUFFER PIC X(80) VALUE SPACES. 01 RECORD-BUFFER PIC X(80) VALUE SPACES. 01 SEARCH-BUFFER PIC X(80) VALUE SPACES. 01 VALUE-BUFFER PIC X(80) VALUE SPACES. 01 ISN-BUFFER PIC X(80) VALUE SPACES. PROCEDURE DIVISION . MOVE ‘OP’ TO COMMAND-CODE. CALL ‘ADABAS’ USING CONTROL-BLOCK,FORMAT-BUFFER IF NOT SUCCESSFUL THEN PERFORM ERROR-ROUTINE. MOVE +202 TO FILE-NUMBER. PERFORM FIND-ROUTINE. MOVE 0 TO ISN. FIND – ROUTINE. MOVE ‘S1’ TO COMMAND-ID. MOVE ‘DH01’ TO COMMAND-ID. CALL ‘ADABAS’ USING CONTROL-BLOCK,SEARCH,BUFFER,VALUE-BUFFER,ISN-BUFFER CLOSE-ROUTINE MOVE ‘CL’ TO COMMAND-CODE . CALL ‘ADABAS’ USING CONTROL-BLOCK. IF NOT SUCCESSFUL THEN PERFORM ERROR-ROUTINE. INTRODUCTION TO ADASQL : ADABAS SQL allows access to adabas by the emerging standard for structured relational data languages.ADABAS SQL integrated with PREDICT for centralized control of all corporate data. The integration with PREDICT provides access to the definition of database files/tables and fields as well as PREDICT’s cross-referencing facility.Cross references are maintained by program-name files or fields referenced ,copycode members accessed and also by programming language,date and time compiled. Programs with ADASQL statements are converted during execution of a preprocessor step prior to compilation.The resulting source contains the ADASQL statements , the generated code and the original host language source code.Any changes must be passed the preprocessor before recompilation. Topics to be covered : 1. Program Preparation 2. ADABAS Buffer overview 3. ADASQL Statements 4. Single record processing 5. Multiple record processing 6. Online Processing with ADASQL 7. Examples ADABAS SQL PREPROCESSOR Generated Program Host Compiler Object Module LINKAGE EDITOR Load Module Source Program with ADABAS SQL Statements PREDICT Data Dictionary Cross Reference Facility ADABAS PROGRAM PREPARATION ADABAS BUFFER OVERVIEW : • The record buffer is an area of storage allocated by the program which is used by ADABAS to transfer information from the database to the program and vice- versa. • If an ALIAS is specified in the ADABAS SQL Command which creates the record buffer ,then that name is used as the level 1 qualifier.If an alias is not specified then the filename or view name is used as the level 1 qualifier. • The attributes for the fields referred in ADASQL are taken from PREDICT, the data dictionary. • To refer to the data base fields from a COBOL Program, the syntax would be : <field-name > OF <buffer-name> • ADABAS SQL appends three fields to each record in the Record Buffer.The fields are defined as follows : • ISN A four byte binary field containing the Internal Sequence Number of the record found cobol structure is : PIC 9(9) COMP • QUANTITY A four byte binary field containing the number of records found for the specific search criteria. COBOL Structure is : PIC 9(9) COMP When used with HISTOGRAM , QUANTITY contains the count field from the Inverted list,that is the number of records in the database for that specific descriptor value. • RESPONSE-CODE A two byte binary field containing the response code for the execution of the ADABAS SQL Command. COBOL Structure is : PIC 9(4) COMP ADASQL STATEMENTS : • General Statement Syntax EXEC ADABAS ADABAS SQL-Statement END-EXEC • Retrieval Types statement -name FIND READ { PHYSICAL { SEQUENCE} READ LOGICAL READ ISN HISTOGRAM SORT [ISN {LIST[S]] • General Syntax. EXEC ADABAS Statement-name [ DECLARE cursor-name CURSOR [FOR] ] [ SELECT { select-list / * } ] FROM file [ alias] …. [ WHERE search-criteria] OPTIONS < REFER NEXT SLIDE > ORDER BY descriptor…… DESC/ASC GROUP BY descriptor END-EXEC ADASQL STATEMENTS (Continue…… ) OPTIONS : INDEXED = { Y / N } COND-NAME = { Y / N} HOLD [ RETURN] PASSWORD = { CONSTANT/VARIABLE/ :VARIABLE} CIPHER = { CONSTANT/VARIABLE/ :VARIABLE} ISNSIZE = Length {CONSTANT/VARIABLE} SAVE SEQUENCE ISN = VALUE PREFIX = Prefix SUFFIX = Suffix STATIC = { Y / N } MAXTIME = ss AUTODBID DBID = database-name • FIND - Produces as ISN list for all the records which satisfy the given search criteria . - The only OPTIONS available for a FIND are HOLD, PASSWORD , CIPHER , ISNSIZE and SAVE - The list may be sorted in ORDER BY a DESCRIPTOR - The GROUP BY clause is not permitted for a FIND - The search criteria for the FIND is specified in WHERE <Search Criteria> - In search option we can specify following conditions DESCRIPTOR (EQ,GT,GE,LT,LE ) Expression/values or DESCRIPTOR (=,>,>=,<,<=) Expression /values • READ PHYSICAL SEQUENCE - Records are read in the order that they are physically stored in the database. - Only one file may be specified in the FROM clause - The WHERE , ORDER BY , GROUP BY should not be coded with READ PHYSICAL - The only options available for a READ PHYSICAL are HOLD , PASSWORD , CIPHER and ISN • READ LOGICAL - Records are read in ascending logical order based on a given descriptor - Only one file can be specified in FROM clause - If alias is specified ,it is used as the same name of the record buffer . If it is not specified , the file name is used. - The OPTIONS available for READ LOGICAL are HOLD , PASSWORD , CIPHER and ISN - The descriptor specified in the ORDER BY clause must be the same as the descriptor in the WHERE clause - The WHERE clause specifies the starting point for the read of a descriptor. • READ ISN - Reads data from a record based on a given ISN value. - only one file name can be specified in FROM clause - If alias is specified that can be used as record buffer. - The only OPTIONS available for READ ISN is HOLD,PASSWORD,CIPHER and SEQUENCE - WHERE ISN = (CONST / VARIABLE) CURRENT OF cursor-name • HISTOGRAM - This determines the values which are currently present for a descriptor. The number of records which contain that descriptor value is also available. - only one file can be specified in FROM clause - if alias is specified that can be used as a record buffer name - the only options available for a HISTOGRAM is PASSWORD - The list can be sorted by a descriptor specified with the ORDER BY clause. - WHERE descriptor BETWEEN value AND value descriptor GT/EQ value • OPTIONS Clause - INDEXED , is available for Cobol program only.MU / PU will be generated with the indexed by keywords. - COND-NAME = Y , Condition name defined to PREDICT may be generated into record buffers of COBOL programs. These are defined as level-88 entries if COND-NAME = Y - HOLD is specified , the retrieved record is placed in hold status and can't be updated or deleted by another user. - PASSWORD , Must be specified if the file is secured thru ADABAS. - CIPHER , If the file is encrypted. - ISNSIZE indicates the maximum number of ISNs which can be stored in the ISN Buffer - SAVE option is used to retain the ISN list.It will be deleted when a CLOSE is executed. - SEQUENCE ,Record with the specified ISN will be retrieved . - ISN , record will be retrieved with specified ISN value MULTIPLE RECORD PROCESSING : - EXEC ADABAS OPEN cursor-name END-EXEC. - EXEC ADABAS FETCH cursor-name END-EXEC. - EXEC ADABAS CLOSE cursor-name END-EXEC • DELETE EXEC ADABAS DELETE [ DECLARE cursor-name CURSOR FROM file ISN = Value CURRENT OF cursor-name OPTIONS (PASSWORD/CIPHER/STATUS) END-EXEC • INSERT EXEC ADABAS INSERT INTO file [alias] WHERE ISN = Value, SET field = (constant / value) OPTIONS = (PASSWORD/CIPHER/PREFIX/STATUS) END-EXEC • UPDATE EXEC ADABAS UPDATE file [alias] [ DECLARE cursor-name CURSOR ] FROM file WHERE ISN = value CURRENT OF cursor-name OPTIONS PASSWORD PREFIX CIPHER STATUS END-EXEC OTHER COMMANDS : • EXEC ADABAS BEGIN DECLARE SECTION END-EXEC • EXEC ADABAS CONNECT <user id> ACC = file OPTIONS DBID = < database name> END-EXEC • EXEC ADABAS DBCLOSE OPTIONS DBID=database-name END-EXEC • EXEC ADABAS COMMIT WORK END-EXEC • EXEC ADABAS ROLLBACK WORK END-EXEC EXAMPLES : DATA RETRIEVAL : EXEC ADABAS BEGIN DECLARE SECTION END-EXEC EXEC ADABAS DECLARE PERS CURSOR FOR SELECT LASTNAME,FIRSTNAME,MIDDLE-INIT,SEX,SALARY FROM PERSONNEL WHERE LASTNAME = ‘HARRIS’ END-EXEC … EXEC ADABAS OPEN PERS END-EXEC …. EXEC ADABAS FETCH PERS END-EXEC PERFORM READ-PERS UNTIL ADACODE = 3. EXEC ADABAS CLOSE PERS END-EXEC STOP RUN READ-PERS. DISPLAY LAST-NAME FIRST-NAME MIDDLE-INIT AGE SEX SALARY. EXEC ADABAS FETCH PERS END-EXEC. DATA CREATION : EXEC ADABAS BEGIN DECLARE SECTION END-EXEC ….. EXEC ADABAS INSERT INTO PERSONNEL SET LAST-NAME = ‘HARRIS’ FIRST-NAME = ‘CODY’ MIDDLE-INIT = ‘A’ SEX = ‘M’ SALARY = 146500 END-EXEC …… EXEC ADABAS COMMIT WORK END-EXEC. DATA MODIFICATION : EXEC ADABAS BEGIN DECLARE SECTION END-EXEC ….. EXEC ADABAS DECLARE PERS CURSOR SELECT LAST-NAME,FIRST-NAME,MIDDLE-INT,SEX,SALARY FROM PERSONNEL WHERE LAST-NAME = ‘HARRIS’ OPTIONS HOLD END-EXEC. …… EXEC ADABAS UPDATE PERSONNEL SET SALARY = 54500 WHERE CURRENT OF PERS END-EXEC EXEC ADABAS COMMIT WORK END-EXEC ….. EXEC ADABAS DBCLOSE END-EXEC DATA DELETION : EXEC ADABAS BEGIN DECLARE SECTION END-EXEC ….. EXEC ADABAS DECLARE PERS CURSOR FOR FROM PERSONNEL WHERE PERSONNEL-NUMBER=070187 OPTIONS HOLD END-EXEC. …… EXEC ADABAS FETCH PERS END-EXEC EXEC ADABAS DELETE WHERE CURRENT OF PERS END-EXEC EXEC ADABAS COMMIT WORK END-EXEC ….. EXEC ADABAS DBCLOSE END-EXEC