Performance tips

To improve performance of the extract program, consider adding the following indexes to the Db2® catalog:

On SYSDBAUTH
(database(,grantor,grantee))
On SYSCHECKS
(tbowner,tbname)
On SYSRELS
(creator,tbname,relname)
On SYSRESAUTH
(qualifier,name(,grantor,grantee,obtype))
On SYSTABAUTH
(tcreator,ttname(,grantor,grantee,granteetype))
On SYSCOLAUTH
(creator,tname(,dategranted,timegranted))

The recommended mode of operation is batch, even if only a few objects are requested. This is because the design process is based on the standard Db2® catalog indexes, which means that some parts of the process scan the catalog tables instead of doing a direct reference.

Considerations

The following considerations apply to reverse engineering:
  • FM/Db2 does not extract IDCAMS DEFINE CLUSTER statements for VCAT-defined table spaces and indexes.
  • The generated SQL for table spaces and indexes defined with a DSETPASS (password) contains a SPUFI comment line such as:
        --     DSETPASS XXXXXXXX
    FM/Db2 does not reveal the data set password in the catalog; FM/Db2 generates the comment line and issues a warning.
  • The ability to generate actually allocated or actually used space allocations depends on information in the Db2® catalog. The actual data set sizes for table spaces or index spaces are not retrieved. Only use these options if you have recently run STOSPACE and RUNSTATS for the selected objects.