Shrinking Log Space

The alter database command includes a log off parameter that removes unwanted portions of a database log, allowing you to shrink log space and free storage without re-creating the database.

alter database database_name [log off database_device
	[= size | [from logical_page_number] [to logical_page_number]]
	[, database_device
	[= size | [from logical_page_number] [to logical_page_number]]

The parameter may be particularly helpful after running the fully logged option for database operations, such as select into, alter table, or reorg rebuild, when the database ends up with extra allocated space that is no longer needed. See the dump transaction command the Reference Manual: Commands.

• Using dump and load database When Shrinking Log Space
  Shrinking log space requires careful planning.
• Using dump and load transaction When Shrinking Log Space
  The size of a log might change during a dump sequence in which the database is first dumped, and then transaction log dumps are performed periodically.