Bug#48582: psql spends hours computing results it already knows (fwd)

This is a Debian bug report, which needs upstream attention.

------- Forwarded Message

Date: Thu, 28 Oct 1999 13:45:18 -0400
From: Brian Ristuccia <brianr(at)osiris(dot)978(dot)org>
To: submit(at)bugs(dot)debian(dot)org
Subject: Bug#48582: psql spends hours computing results it already knows

Package: postgresql
Version: 6.5.2-3

massive_db=> explain select count(*) from huge_table;
NOTICE: QUERY PLAN:

Aggregate (cost=511.46 rows=9923 width=12)
-> Seq Scan on huge_table (cost=511.46 rows=9923 width=12)

EXPLAIN

If huge_table really is huge -- like 9,000,000 rows instead of 9923, after
postgresql already knows the number of rows (that's how it determines the
cost), it proceeds to do a very long and CPU/IO intensive seq scan to
determine the count().

- --
Brian Ristuccia
brianr(at)osiris(dot)978(dot)org
bristucc(at)nortelnetworks(dot)com
bristucc(at)cs(dot)uml(dot)edu

------- End of Forwarded Message

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