Implementing Siebel Business Applications on DB2 UDB for z/OS > About Migrating a Siebel Database to Unicode Format >

About Unicode Storage Requirements

The use of the Unicode UTF-16 encoding format increases the storage required by your Siebel database. During the Unicode migration process, data types in the Siebel ASCII or EBCDIC database are mapped from single-byte to double-byte characters, as shown in Table 15.

Moving from single-byte to double-byte characters causes some Siebel table spaces to exceed their page sizes and causes some tables to exceed the 32 KB limit; these tables will require DBCLOB or LOB columns in the Unicode database.

To help you estimate the increase in storage that might occur when you migrate from a code page to a Unicode database, Table 16 shows the number of table spaces and the storage required by a sample SIA 8.0 EBCDIC database, and the storage and table spaces required by the same database when it has been migrated to Unicode.

NOTE:  The figures in Table 16 are provided as a guideline only. The increase in storage required by your actual Unicode database might be greater or lesser than indicated for the sample database.

Siebel v8.0 uses COMPRESS=YES as the default for table space definitions; this reduces the storage requirements for table spaces.

About the NOT PADDED Clause

To minimize any increase in storage when you migrate your database to Unicode, indexes in the Siebel Schema are defined with the NOT PADDED clause by default when you convert your storage control file to Unicode using the Siebel Database Storage Configurator.

When the NOT PADDED clause is specified:

• Varying-length columns of an index are not padded to their maximum length; DB2 stores only the key data, which reduces the storage required by the index key.
• VARGRAPHIC columns of an existing index are stored as varying-length columns.

  If the NOT PADDED clause is not specified, VARGRAPHIC columns are stored as fixed-length columns.

You can specify that indexes are to be NOT PADDED by default by specifying the PADIX DSNZPARM. You can also use the PADDED or NOT PADDED clauses in the CREATE INDEX or ALTER INDEX statements to specify whether an individual index is padded or not.