Re: optimizing large query with IN (...) - Mailing list pgsql-performance

Marcus Andree S. Magalhaes wrote:
> Guys,
>
> I got a Java program to tune. It connects to a 7.4.1 postgresql server
> running Linux using JDBC.
>
> The program needs to update a counter on a somewhat large number of
> rows, about 1200 on a ~130k rows table. The query is something like
> the following:
>
> UPDATE table SET table.par = table.par + 1
> WHERE table.key IN ('value1', 'value2', ... , 'value1200' )
>

How often do you update this counter?  Each update requires adding a new
row to the table and invalidating the old one.  Then the old ones stick
around until the next vacuum.