From: Kevin Grittner <kgrittn@ymail.com>
To: Jeison Bedoya <jeisonb@audifarma.com.co>
To: pgsql-performance@postgresql.org <pgsql-performance@postgresql.org>
Subject: Re: to many locks held
Date: Fri, 2 Aug 2013 14:03:28 -0700 (PDT)
Message-ID: <1375477408.36283.YahooMailNeo@web162901.mail.bf1.yahoo.com> (raw)
In-Reply-To: <51F79AEC.3070103@audifarma.com.co>
References: <51F79AEC.3070103@audifarma.com.co>
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Jeison Bedoya <jeisonb@audifarma.com.co> wrote:
> memory ram: 128 GB
> cores: 32
>
> max_connections: 900
> temp_buffers = 512MB
In addition to the other comments, be aware that temp_buffers is
the limit of how much RAM *each connection* can acquire to avoid
writing temporary table data to disk. Once allocated to a
connection, it will be reserved for that use on that connection
until the connection closes. So temp_buffers could lock down 450
GB of RAM even while all connections are idle. If the maximum
connections become active, and they average one work_mem allocation
apiece, that's an *additional* 900 GB of RAM which would be needed
to avoid problems.
Reducing connections through a pooler is strongly indicated, and
you may still need to reduce work_mem or temp_buffers.
http://wiki.postgresql.org/wiki/Number_Of_Database_Connections
--
Kevin Grittner
EDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
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Cc: kgrittn@ymail.com, jeisonb@audifarma.com.co
Subject: Re: to many locks held
In-Reply-To: <1375477408.36283.YahooMailNeo@web162901.mail.bf1.yahoo.com>
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