What is DDL sync and how to do it?

DDL Sync is one of the most important step as part of code migration to new environment.
So here we will discuss

• why do we perform DDL sync?
• What are the steps involved in this process? and
• How can we do this?

DDL Sync
DDL sync is used to have a sync between your Siebel Repositories & physical schema in Oracle DB. ddlsync compares the logical schema (schema definitions in your repository) with your physical schema (i.e. physical db table/column definitions) and applies the differential changes on the physical schema so that they are both in sync 

Steps involved
DDL Sync is 3 steps process which includes

• ddldict to export customer schema definitions from the repository into schema.ddl file .
• ddlimp to apply the schema definitions in schema.ddl to the physical schema ignoring error .
• ddlimp to apply the schema definitions in schema.ddl and stop on error to ensure that logical and physical DB are in sync. 

How to perform DDL Sync

DDL sync can be done through Wizard which can be invoked by 

[ ] 1 - Install Database

[ ] 2 - Upgrade Database

[ ] 3 - Apply Additive Schema Changes

[ ] 4 - Import/Export Repository

[ ] 5 - Migrate Repository

[X] 6 - Run Database Utilities

or we can do DDL sync with separate commands.

Navigate to bin directory in siebsrvr.

ddldict /u sadmin /p ###### /c Enterprise_DSN /d siebel /f /#####/81/siebsrvr/schema.ddl /e y /a y /l /######/81/siebsrvr/log/sch_dict.log /n "Siebel Repository" /t dcir

Above command will generate Schema.ddl at the specified location.Now we have to apply the schema changes to Physical DB.

ddlimp /u SIEBEL /p ###### /c Enterprise_DSN /g SSE_ROLE /f /#####/81/siebsrvr/schema.ddl /e n /B SIEBELDATA /X SIEBELINDEX /R Y /W Y /s Y /l /#####/81/siebsrvr/log/ddlsync/output/ddlsync.log