Can BRSPACE online reorg 'SYS' ‘SYSTEM’ tables？

[Former Member]

Dear expert,

I would like to know can we reorg (in order to OLTP compression table)  the table under the schema 'SYS' or 'SYSTEM'

Thank you

kate

[ACE-SAP · Accepted solution]

Hi Kate,

BRTools does not allow you to reorganize system tablespace as stated in the here under note.

It might be possible to reorganize some tables depending on their usage, but it could be risky.

Why would you reorganize the system tablespace ?

Reorganization should only performed when important deletion took place to either reduce fragmentation or reclaim space.

Do you have such big segments in system tablespace that a compression could make sens ?

Regards

646681 - Reorganization of tables with BRSPACE

Of course, you CANNOT reorganize the SYSTEM tablespace by using the methods described in this note. From a logical point of view, you can "reorganize" the SYSTEM tablespace by recreating the database. Note 748434 describes how this action can be performed with BRSPACE.

748434 - New BRSPACE function "dbcreate" - recreate database

The new "Create new database"/"Recreate database" (call: brspace -f dbcreate) allows you to recreate the system tablespace. Logically, this results in the SYSTEM tablespace being "reorganized".

541538 - FAQ: Reorganization

Table reorganization can be useful in

• Move hot spots at disk level
• Low table fill level: If blocks of tables are largely empty (archive, del.) => unnecessary number of blocks are read to Oracle buffer for a small amount of data.
• Changing the storage parameters of blocks that were already allocated: If you want to change memory parameters such as INITRANS (Note 84348) or FREELIST_GROUPS (Note 619188), you can only do so within a reorganization process.
• Moving segments to another tablespace (isolate a table in a specific TS)
• Reducing chained or migrated rows
• Reducing extents =>  DMTS with a large number of extents -> avoid unforeseen ST enqueue problems (see Note 787533).
• Converting from LONG columns to LOB columns
• Change to table entries: In certain cases, it may make sense to rebuild a table with a particular sorting -> improve clustering factor of an index (Note 832343).