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What are .fdk Files in the SQL_SYS Directory?

FairCom DB SQL maintains the SQL system tables in the <dbname>.dbs\SQL_SYS\<dbname>.fdd file. This file is a standard FairCom DB superfile; a file containing all of the system tables and indexes. For example

.\ctreeSQL.dbs\SQL_SYS\ctreeSQL.fdd

There is one .dbs directory and .fdd system table per SQL database.

When FairCom DB SQL upgrades require changes to the system tables, a conversion automatically takes place upon server startup, with all databases listed in the session dictionary (ctdbdict.fsd). The process is as follows:

  1. The existing <dbname>.fdd file is copied to <dbname><timestamp>.fdk
  2. FairCom DB SQL performs the conversions on <dbname>.fdd
  3. A template database, __Master.dbs, database is created and comparisons made for validation

Each database found is converted in a separate transaction. If the conversion fails for any reason, for example, an abnormal shutdown of the server, <dbname>.fdk can be copied back to <dbname>.fdd. Check CTSTATUS.FCS for any reported conditions when updating FairCom DB SQL.

The following FairCom DB SQL versions require system table upgrades:

  • V9.5
  • V9.3
  • V8.27

Note: To prevent a database conversion, the SQL_OPTION NO_DB_CONVERSION keyword can be added to the configuration file. This should only be used upon the recommendation of FairCom support.

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