Re: row migaration

The tumbstones are removed when the row is deleted. Obviously any form of reorganization export/drop and re-create or truncate/import, CTAS (create table as select), or use of DBMS_REDEFINITION (online reorganization) deletes the row.

Tumbstones should be rare. If you have a table with a significant chain count that is not due to rows exceeding the Oracle block size then the table pctfree parameter, which reserves space within a block for updates, was set too low on object creation. You can run a re-org and use more appropriate pctfree value. Then future reorganizations should be unnecessary.

Table and index reorganizations rarely have performance benefits in Oracle; however, reorganization can often be beneficial from a space management point of view. It depends on the DML activity pattern.

HTH -- Mark D Powell -- Received on Wed Jan 04 2006 - 09:12:28 CST