Re: BUG #5492: Query performs slowly and sequence corrupted

On Mon, Jun 7, 2010 at 5:33 PM, Greg Stark <gsstark@mit.edu> wrote:
> On Mon, Jun 7, 2010 at 5:36 PM, Piergiorgio Buongiovanni
> <piergiorgio.buongiovanni@netspa.it> wrote:
>> I reused the previous command to re-set the sequence value to the right one,
>> but I see that the START value is now 59100. I reused the previous command
>> another time and the START value is now 30440.
>>
>> I think this is a bug. I have a lot of problems with this sequence.
>
> Sequences wouldn't directly affect retrieval times. But one way you
> could get both of these symptoms is by having an application which
> inserts many rows but aborts and rolls back the inserts without
> committing. Perhaps a large copy which is interrupted. That would fill
> the table with garbage dead records which could slow down retrieval
> depending on the access method and also increase the sequence value.

If this is what happened, CLUSTER on the table might be enough to fix
the problem.

--
Robert Haas
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