Re: Very inefficient query plan with disjunction in WHERE clause

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

To: Koen Martens <pgsql@xxxxxxxx>
Subject: Re: Very inefficient query plan with disjunction in WHERE clause
From: Віталій Тимчишин <tivv00@xxxxxxxxx>
Date: Mon, 1 Jun 2009 19:19:12 +0300
Cc: pgsql-performance@xxxxxxxxxxxxxx
In-reply-to: <20090601160206.GA4790@xxxxxxxxxxxx>
References: <20090601160206.GA4790@xxxxxxxxxxxx>

2009/6/1 Koen Martens <pgsql@xxxxxxxx>

Now, when I split up the OR in two distinct queries, everything is nice and fast. Both queries run in sub-second time.

Hi.

PostgreSQL simply do not like ORs (can't use indexes in this case), so UNION/UNION ALL is your friend.

Best regards, Vitalii Tymchyshyn

References:
- Very inefficient query plan with disjunction in WHERE clause
  - From: Koen Martens

Prev by Date: Re: Using index for bitwise operations?
Next by Date: Re: Best way to load test a postgresql server
Previous by thread: Very inefficient query plan with disjunction in WHERE clause
Next by thread: Re: Very inefficient query plan with disjunction in WHERE clause
Index(es):
- Date
- Thread

[Postgresql General] [Postgresql PHP] [PHP Users] [PHP Home] [PHP on Windows] [Kernel Newbies] [PHP Classes] [PHP Books] [PHP Databases] [Yosemite]

Powered by Linux