Обсуждение: Embedded VACUUM

I'm running a labour-intensive series of queries on a medium-sized dataset (~100,000 rows) with geometry objects and
bothgist and btree indices. 

The queries are embedded in plpgsql, and have multiple updates, inserts and deletes to the tables as well as multiple
selectswhich require the indices to function correctly for any kind of performance. 

My problem is that I can't embed a vacuum analyze to reset the indices and speed up processing, and the queries get
slowerand slower as the un-freed space builds up. 

From my understanding, transaction commits within batches are not allowed (so no vacuum embedded within queries).  Are
thereplans to change this?  Is there a way to reclaim dead space for tables that have repeated inserts, updates and
deleteson them?  I have tried a simple analyze, and this does not quite cut it.  I'm getting seq-scans after the first
roundof processing instead of hitting the index correctly. 

My apologies if this is directed at the wrong forum, and thank you for your help.

-cris pond

On 3/09/2011 8:25 AM, C Pond wrote:
> I'm running a labour-intensive series of queries on a medium-sized dataset (~100,000 rows) with geometry objects and
bothgist and btree indices. 
>
> The queries are embedded in plpgsql, and have multiple updates, inserts and deletes to the tables as well as multiple
selectswhich require the indices to function correctly for any kind of performance. 
>
> My problem is that I can't embed a vacuum analyze to reset the indices and speed up processing, and the queries get
slowerand slower as the un-freed space builds up. 
>
>  From my understanding, transaction commits within batches are not allowed (so no vacuum embedded within queries).
Arethere plans to change this?  Is there a way to reclaim dead space for tables that have repeated inserts, updates and
deleteson them? 
Not, AFAIK, until the transaction doing the deletes/updates commits and
so do any older SERIALIZABLE transactions as well as any older running
READ COMMITTED statements.

This is one of the areas where Pg's lack of true stored procedures bites
you. You'll need to do the work via an out-of-process helper over a
regular connection, or do your work via dblink to achieve the same effect.

--
Craig Ringer