From DBArtisan
Jump to: navigation, search

Go Up to Available object actions by DBMS

You can maximize the size of free space chunks in tablespaces to avoid the situation in which an object cannot acquire enough contiguous free space to accommodate its next extent size. Towards this goal, look for opportunities to coalesce adjacent blocks of free space into a single, larger block.

Oracle automatically coalesces adjacent free space chunks with a background process. However, it still supports the commands for coalescing free space manually. Depending on the size of the tablespace, coalescing its free space can take a long time. So determine when to perform this operation. It you coalesce immediately, the tablespace is locked.

Platform Availability

Important Notes

  • You cannot coalesce on an UNDO tablespace.

To Coalesce a Tablespace

  1. Initiate a Coalesce action against one or more tablespaces. For more information see Initiating an object operation.
  2. Use the following table as a guide to understanding and modifying settings in the Coalesce wizard:
Step Settings and tasks

Action options

Verify display of the tablespaces to be coalesced.


Review the referring and referred objects that will be automatically resolved when you execute this operation. For more information, see Dependencies.


Preview the DDL generated for the operation. For more information, see Preview.