On 01/13/2012 07:08 AM, Anibal David Acosta wrote:
How can I release the space used by deleted rows? Without block the table.
The database can only reduce the size tables by returning space to the operating system in one situation: there is free space at the very end of the table. In that case, if it's possible to get a brief exclusive lock on the table, it can shrink in size.
There are some programs available that reorganize table for goals like this, without having any long-lasting locks on the tables. pg_reorg is the most popular example:
http://pgfoundry.org/projects/reorg/--
Greg Smith 2ndQuadrant US greg@2ndQuadrant.com Baltimore, MD
PostgreSQL Training, Services, and 24x7 Support www.2ndQuadrant.com