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DATABASE MIGRATION The general method. Source technical objects (DDL, programs, jcl,..). Source cartography & modeling. Source base model. Target base re-engineering. Target base structures. Data migration. Target base loaded. Programs adaptation. Application migrated.
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DATABASE MIGRATIONThe general method Source technical objects (DDL, programs, jcl,..) Source cartography & modeling Source base model Target base re-engineering Target base structures Data migration Target base loaded Programs adaptation Application migrated
MODELING synthesis Physical model Logical model Semantic model # entity types 112 112 105 # relations 73 128 110 # attributes 1249 1509 1210
DATABASE MIGRATIONThe general method Source technical objects (DDL, programs, jcl,..) Source cartography & modeling Source base model Target base re-engineering Target base structures Data migration Target base loaded Programs adaptation Application migrated
DATA BASE RE-ENGINEERING Semantic model Relational model DB design • adding a primary ky to each table (good practise) • relations foreign keys • relations N-N intermediate table + foreign key • redefines separate tables + foreign keys • composed attributes decomposition • multivaluated attributes separated tables + foreign keys OR attributes list • name treatment : “-” “_”, reserved words
DATABASE RE_ENGINEERINGgeneration of target base descriptive objects • Standard SQL or • DB2 • Oracle • SQL Server • MySQL • PostgreSql • …
DATABASE RE-ENGINEERING synthesis Physical model Logical model Semantic model Relational model # entity type 112 112 105 147 # relations 73 128 110 144 (FK) # attributes 1249 1509 1210 1841
DATABASE RE-ENGINEERING mapping Source logical model Source physical model Target relational model The DB-MAIN transformation functions are maintaining the links between the models evolution steps
DATABASE MIGRATIONThe general method Source technical objects (DDL, programs, jcl,..) Source cartography & modeling Source base model Target base re-engineering Target base structures Data migration Target base loaded Programs adaptation Application migrated
DATA MIGRATIONunloading • Unloading model creation : • physical model • DB-key • “mvs” meta-properties
DATA MIGRATIONunloading • Processing components generation : • PSB • PSB compilation Jcl • Unloading Cobol program • programs compilation JCL • file creation and execution JCL
DATA MIGRATIONdata validation • Data validation and transformations generation : • type of records description (attributes, lenght, format, …) • programs to validate the conformity of the source data to the target model ( null char…) • transcoding programs for EBCDIC to ASCII conversion, add EOL characters, … • execution scripts scheduling the opertions sequence
DATA MIGRATION data loading • Components generation for loading the target base : • CTL file for the loading utility of DB2, SQL*Loader, … • Shell scripts
DATA MIGRATIONmigration validation – functional counters Generation of checksum onto source and target environments
DATA MIGRATIONdation de la migration – data validation – content comparison process
DATA MIGRATION migration validation – content comparison Common model
DATABASE MIGRATIONThe general method Source technical objects (DDL, programs, jcl,..) Source cartography & modeling Source base model Target base re-engineering Target base structures Data migration Target base loaded Programs adaptation Application migrated
PROGRAMS ADAPTATION access modules generation COBOL Program IMS DB CALL “CBLTDLI” USING … EXEC DLI … USING … Transformation WRXXX.cob DELETE CALL COBOL Program’ FETCH Relational DB CALL WRYYY.cob INSERT CALL WRZZZ.cob UPDATE • Modification of the data and files “declarations” • Generated code insert • Replacement of the DML verbs by calls to the acces modules
PROGRAMS ADAPTATION access modules generation • Access modules generation ( in this case C++) • Language dependant on the target environment (cobol, java, …)
PROGRAMS ADAPTATION access modules generation Some DML verbs are not automatically resolved : ex: within IMS SSA not qualified : (GU, GN, GNP without segment name) PROCOPT parameter in the PSB within IDS2 FIND within AREA without record name
PROGRAMS ADAPTATION programs source code transformation FIND FIRST USING ART-KEYB. … FIND NEXT RONTB WITHIN DUMMY-RONTB EVALUATE DB-STATUS WHEN "0000000" GET RONTB ... **ReVeR: FIND FIRST USING ART-KEYB MOVE 390000 TO REC-CALL-ID OF WR-LOG PERFORM WR-FFXU-ART-KEYB … **ReVeR: FIND NEXT RONTB WITHIN DUMMY-RONTB MOVE 37060000 TO REC-CALL-ID OF WR-LOG PERFORM WR-FNRW-RONTB-DUMMY-RONTB EVALUATE DB-STATUS WHEN "0000000" **ReVeR: GET RONTB MOVE 37070000 TO REC-CALL-ID OF WR-LOG PERFORM WR-GR-RONTB ...