From: Jim Nasby <jnasby@enova.com>
To: pgsql-performance@postgresql.org <pgsql-performance@postgresql.org>
Subject: Horrific time for getting 1 record from an index?
Date: Mon, 11 Nov 2013 15:48:09 -0600
Message-ID: <52815099.4080409@enova.com> (raw)
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Postgres 9.1.9.
explain analyze select min(insert_time) from cnu_stats.page_hits_raw ;
QUERY PLAN
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------
Result (cost=0.12..0.13 rows=1 width=0) (actual time=257545.835..257545.836 rows=1 loops=1)
InitPlan 1 (returns $0)
-> Limit (cost=0.00..0.12 rows=1 width=8) (actual time=257545.828..257545.829 rows=1 loops=1)
-> Index Scan using page_hits_raw_pkey on page_hits_raw (cost=0.00..5445004.65 rows=47165480 width=8) (actual time=257545.826..257545.826 rows=1 loops=1)
Index Cond: (insert_time IS NOT NULL)
Total runtime: 257545.881 ms
(6 rows)
I checked and there were no un-granted locks... but I have a hard time believing it actually too 257 seconds to get 2 pages (one index, one heap) back from our SAN.
Am I missing something here?
--
Jim Nasby, Lead Data Architect (512) 569-9461
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Cc: jnasby@enova.com
Subject: Re: Horrific time for getting 1 record from an index?
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