Re: Performance die when COPYing to table with bigint PK

04.08.11 18:59, Kevin Grittner написав(ла):
> Robert Ayrapetyan<robert(dot)ayrapetyan(at)comodo(dot)com> wrote:
>> Kevin Grittner<Kevin(dot)Grittner(at)wicourts(dot)gov> wrote:
>
>> [regarding tests which do show the problem]
>> tried same with 2 columns (bigint and int) - it didn't produced
>> such effect probably because data volume has critical effect.
>
> Based on what you're showing, this is almost certainly just a matter
> of pushing your volume of active data above the threshold of what
> your cache holds, forcing it to do disk access rather than RAM
> access for a significant portion of the reads.
>
> -Kevin
Yep. Seems so. Plus famous "you'd better insert data, then create indexes".
On my database it takes twice the time for int8 then for int4 to insert
data.
Also it takes ~twice a time (2 hours) to add 200K of rows to 200M of
rows than to make an index over 200M of rows (1 hour).

Best regards, Vitalii Tymchyshyn