<!-- $PostgreSQL: pgsql/doc/src/sgml/protocol.sgml,v 1.78 2010/02/03 09:47:19 heikki Exp $ -->

<!-- $PostgreSQL: pgsql/doc/src/sgml/protocol.sgml,v 1.79 2010/02/16 20:15:14 momjian Exp $ -->

<chapter id="protocol">

<title>Frontend/Backend Protocol</title>

<para>

The unnamed prepared statement is likewise planned during Parse processing

if the Parse message defines no parameters. But if there are parameters,

query planning occursduringBindprocessing instead. This allows the

planner to make use of the actual values of the parameters providedin

the Bind message when planning the query.

query planning occursevery timeBindparameters are supplied. This allows the

planner to make use of the actual values of the parameters providedby

each Bind message, rather than use generic estimates.

</para>

<note>

}

{

psrc=unnamed_stmt_psrc;

if (!psrc)

ereport(ERROR,