On Tuesday 23 March 2004 18:49, Woody Woodring wrote: > Hello, > > I am using postgres 7.4.2 as a backend for geocode data for a mapping > application. My question is why can't I get a consistent use of my indexes > during a query, I tend to get a lot of seq scan results.
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I'm not sure it wants to be using the indexes all of the time. > Nested Loop Left Join (cost=0.00..23433.18 rows=1871 width=34) (actual > time=0.555..5095.434 rows=3224 loops=1) > Total runtime: 5100.028 ms > Nested Loop Left Join (cost=0.00..76468.90 rows=9223 width=34) (actual > time=0.559..17387.427 rows=19997 loops=1) > Total runtime: 17416.501 ms > Nested Loop Left Join (cost=0.00..29160.02 rows=2327 width=34) (actual > time=0.279..510.773 rows=5935 loops=1) > Total runtime: 516.782 ms #1 = 630 rows/sec (with index on cable_billing) #2 = 1,148 rows/sec (without index) #3 = 11,501 rows/sec (with index) The third case is so much faster, I suspect the data wasn't cached at the beginning of this run. In any case #2 is faster than #1. If the planner is getting things wrong, you're not showing it here. -- Richard Huxton Archonet Ltd ---------------------------(end of broadcast)--------------------------- TIP 7: don't forget to increase your free space map settings
