Re: Shared memory usage in PostgreSQL 9.1 - Mailing list pgsql-general

From Christoph Zwerschke
Subject Re: Shared memory usage in PostgreSQL 9.1
Date
Msg-id 4EDA95AE.7090608@online.de
Whole thread Raw
In response to Re: Shared memory usage in PostgreSQL 9.1  (Christoph Zwerschke <cito@online.de>)
Responses Re: Shared memory usage in PostgreSQL 9.1  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-general
Am 03.12.2011 20:31, schrieb Christoph Zwerschke:
> Then, the corrected sum is 449627320 Bytes, which is only about 2MB less
> than was requested. This remaining discrepancy can probably be explained
> by additional overhead for a PostgreSQL 9.1 64bit server vs. a
> PostgreSQL 8.3 32bit server for which the table was valid.

And this additional overhead obviously is created per max_connections,
not per shared_buffers. While the docs suggest there should be 19kB per
connection, we measured about 45kB per connection. This explains the
about 2MB difference when max_connections is 100.

-- Christoph

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