Re: [PERFORM] performance of SELECT * much faster than SELECT with large offset

2014-10-03 Thread Marti Raudsepp
On Fri, Oct 3, 2014 at 5:39 AM, Tom Lane wrote: > Marc Slemko writes: >> I ran into this oddity lately that goes against everything I thought I >> understood and was wondering if anyone had any insight. > > SELECT * avoids a projection step ... see ExecAssignScanProjectionInfo. It would be cool

Re: [PERFORM] performance of SELECT * much faster than SELECT with large offset

2014-10-02 Thread Tom Lane
Marc Slemko writes: > I ran into this oddity lately that goes against everything I thought I > understood and was wondering if anyone had any insight. SELECT * avoids a projection step ... see ExecAssignScanProjectionInfo. regards, tom lane -- Sent via pgsql-performanc

[PERFORM] performance of SELECT * much faster than SELECT with large offset

2014-10-02 Thread Marc Slemko
I ran into this oddity lately that goes against everything I thought I understood and was wondering if anyone had any insight. Version/env details at the end. The root of it is these query times: marcs=# select * from ccrimes offset 514 limit 1; [...data omitted...] (1 row) Time: 650.280 ms