Обсуждение: is max connections in a database table somewhere

Is the max connections value in a system table somewhere?

Thanks.

--
Geoffrey Myers
Myers Consulting Inc.
770.592.1651

On 08/10/2011 02:46 PM, Geoffrey Myers wrote:
> Is the max connections value in a system table somewhere?

If you intend to do anything with the value you probably want one of
these forms:

SELECT CAST(current_setting('max_connections') AS integer);
SELECT CAST(setting AS integer) FROM pg_settings WHERE
name='max_connections';

The setting comes back as a text field when using current_setting on the
pg_settings view (which isn't a real table, under the hood it's calling
a system function)

--
Greg Smith   2ndQuadrant US    greg@2ndQuadrant.com   Baltimore, MD
PostgreSQL Training, Services, and 24x7 Support  www.2ndQuadrant.us

2011/8/10, Greg Smith <greg@2ndquadrant.com>:
> On 08/10/2011 02:46 PM, Geoffrey Myers wrote:
>> Is the max connections value in a system table somewhere?

Yes, it is in the table "pg_catalog.pg_database". The column is named
"datconnlimit" and is of type "int4". See this:
http://www.postgresql.org/docs/9.0/interactive/catalog-pg-database.html.

But this would be the appropiate way of getting the value:
> SELECT CAST(current_setting('max_connections') AS integer);

You would rather use that form instead of messing up with the catalogs.
--
Diego Augusto Molina
diegoaugustomolina@gmail.com

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Greg Smith wrote:
> On 08/10/2011 02:46 PM, Geoffrey Myers wrote:
>> Is the max connections value in a system table somewhere?
>
> If you intend to do anything with the value you probably want one of
> these forms:
>
> SELECT CAST(current_setting('max_connections') AS integer);
> SELECT CAST(setting AS integer) FROM pg_settings WHERE
> name='max_connections';
>
> The setting comes back as a text field when using current_setting on the
> pg_settings view (which isn't a real table, under the hood it's calling
> a system function)

Actually, just pulling it out of the database to display it in a report.


--
Until later, Geoffrey

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