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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Igor Korot <ikorot01@gmail.com>
cc: "pgsql-generallists.postgresql.org" <pgsql-general@lists.postgresql.org>
Subject: Re: Double prepare
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Igor Korot <ikorot01@gmail.com> writes:
> Is there a way to see if the query has been prepared already (in libpq)?

Use the pg_prepared_statements view.  I don't think libpq keeps any
client-side state about this.

> Or is it better to run PQprepare for all known parameterized queries
> in the very beginning of the program and just execute them when needed?

Very probably.  Querying pg_prepared_statements every time would be
expensive.

			regards, tom lane