Re: Migration from DB2 to PostgreSQL

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От Chris Angelico
Тема Re: Migration from DB2 to PostgreSQL
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Msg-id CAPTjJmrMSFXjWDpj2HLxMAj87+N9zZcp8dMAjkoBinugdhH1tQ@mail.gmail.com
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Ответ на Re: Migration from DB2 to PostgreSQL  (Amit Langote <amitlangote09@gmail.com>)
Ответы Re: Migration from DB2 to PostgreSQL  (Amit Langote <amitlangote09@gmail.com>)
Список pgsql-general
On Thu, Jun 20, 2013 at 11:10 AM, Amit Langote <amitlangote09@gmail.com> wrote:
> If this particular function is to be used repeatedly in a single
> query, would the cost of having a wrapper function around the original
> function be too large? For example, if this function appears in a
> WHERE clause against a table containing millions of rows.

If your wrapper function is written in SQL and is trivial (eg ignore
the third parameter and pass the other two on), the planner should be
able to optimize right through it. Best way to find out is with
EXPLAIN, which I've been using a good bit lately. The optimizer's
pretty smart.

ChrisA


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