Обсуждение: free space map
Is there anyway to query the free space map and see how many entries there are for a specific table?
We are starting to have some performance issues since our upgrade to 8.1 (running 8.1.3). However I can vacuum one table and the issues are temporarily solved. I am trying to do some research and would like to know what the fsm looks like before and after I vacuum this table.
Is this possible?
Thanks,
Chris
RH 4
PG 8.1.3
We are starting to have some performance issues since our upgrade to 8.1 (running 8.1.3). However I can vacuum one table and the issues are temporarily solved. I am trying to do some research and would like to know what the fsm looks like before and after I vacuum this table.
Is this possible?
Thanks,
Chris
RH 4
PG 8.1.3
Chris Hoover wrote: > Is there anyway to query the free space map and see how many entries there > are for a specific table? > > We are starting to have some performance issues since our upgrade to > 8.1(running > 8.1.3). However I can vacuum one table and the issues are temporarily > solved. I am trying to do some research and would like to know what the fsm > looks like before and after I vacuum this table. In CVS HEAD there is a pg_freespacemap contrib module that may do what you need. You'd have to "backport" it to 8.1 though; it doesn't compile as-is. -- Alvaro Herrera http://www.CommandPrompt.com/ PostgreSQL Replication, Consulting, Custom Development, 24x7 support
Alvaro Herrera <alvherre@commandprompt.com> writes: > In CVS HEAD there is a pg_freespacemap contrib module that may do what > you need. You'd have to "backport" it to 8.1 though; it doesn't compile > as-is. Looking at the CVS history, I think the main point is that freespace.c did not formerly expose its internal data structures; the patch moved a lot of declarations into freespace.h so that the contrib code could get at them. You'd need to modify the 8.1 sources, but not by much. regards, tom lane