From: pginfo <pginfo@t1.unisoftbg.com>
To: pgsql-sql@postgresql.org <pgsql-sql@postgresql.org>
Subject: problem with max and not using index on PK
Date: Sat, 03 May 2003 11:12:22 +0200
Message-ID: <3EB387F6.F3230162@t1.unisoftbg.com> (raw)
Hi,
I am using PG 7.3.1
The query plan is:
mydb=# explain analyze select max(IDS) from t_sk10;
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------
Aggregate (cost=61742.78..61742.78 rows=1 width=64) (actual
time=11221.42..11221.43 rows=1 loops=1)
-> Seq Scan on t_sk10 (cost=0.00..60076.22 rows=666622 width=64)
(actual time=16.59..9968.00 rows=666622 loops=1)
Total runtime: 11221.50 msec
(3 rows)
Time: 11222.68 ms
The time is very big.
For example if I start it on oracle, it take ~ 100 ms !
The column IDS is the PK. It is declared as name.
I do not know the reason for not using index in this case.
Also if I get another (not indexed column) and start also max, PG i
working 4 time quicker as oracle and it is great.
Regards,
ivan.
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Subject: Re: problem with max and not using index on PK
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