From: | Rob Wultsch <wultsch(at)gmail(dot)com> |
---|---|
To: | Yan Cheng Cheok <yccheok(at)yahoo(dot)com> |
Cc: | pgsql-general(at)postgresql(dot)org |
Subject: | Re: What is Cost 100 in stored procedure |
Date: | 2010-01-13 04:22:05 |
Message-ID: | 2c5ef4e31001122022q52cbc7c9t5739c4a1bbe539a3@mail.gmail.com |
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Lists: | pgsql-general |
On Tue, Jan 12, 2010 at 8:06 PM, Yan Cheng Cheok <yccheok(at)yahoo(dot)com> wrote:
> May I know what is the meaning of Cost 100, at the end of stored procedure?
>
> ....
> END;$BODY$
> LANGUAGE 'plpgsql' VOLATILE
> COST 100;
> ALTER FUNCTION create_tables() OWNER TO postgres;
>
> Thanks and Regards
> Yan Cheng CHEOK
>
"execution_cost
A positive number giving the estimated execution cost for the
function, in units of cpu_operator_cost. If the function returns a
set, this is the cost per returned row. If the cost is not specified,
1 unit is assumed for C-language and internal functions, and 100 units
for functions in all other languages. Larger values cause the planner
to try to avoid evaluating the function more often than necessary. "
http://www.postgresql.org/docs/8.4/interactive/sql-createfunction.html
--
Rob Wultsch
wultsch(at)gmail(dot)com
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