[PERFORM] Performance discrepancy

2009-06-16 Thread Mark Steben
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Re: [PERFORM] performance discrepancy indexing one column versus

2005-09-11 Thread Gavin Sherry
On Sun, 11 Sep 2005, Mark Dilger wrote: > All, > > In the psql output below, I would expect the second query to run faster, > because the b-tree index on two columns knows the values of 'b' for any > given value of 'a', and hence does not need to fetch a row from the > actual table. I am not seei

[PERFORM] performance discrepancy indexing one column versus two columns

2005-09-11 Thread Mark Dilger
All, In the psql output below, I would expect the second query to run faster, because the b-tree index on two columns knows the values of 'b' for any given value of 'a', and hence does not need to fetch a row from the actual table. I am not seeing a speed-up, however, so I expect my understan