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<chapter id="plpython">

<title>PL/Python - Python Procedural Language</title>

<para>

When you prepare a plan using the PL/Python module it is

automatically saved. Read the SPI documentation (<xref

linkend="spi">) for a description of what this means. The take

home message is if you do

linkend="spi">) for a description of what this means.

</para>

<para>

In order to make effective use of this across function calls

one needs to use one of the persistent storage dictionaries

<literal>SD</literal> or <literal>GD</literal>, see

<xref linkend="plpython-funcs">. For example:

<programlisting>

plan = plpy.prepare("SOME QUERY")

plan = plpy.prepare("SOME OTHER QUERY")

CREATE FUNCTION usesavedplan ( ) RETURNS TRIGGER AS '

if SD.has_key("plan"):

plan = SD["plan"]

else:

plan = plpy.prepare("SELECT 1")

SD["plan"] = plan

# rest of function

' LANGUAGE 'plpython';

</programlisting>

you are leaking memory, as I know of no way to free a saved plan.

The alternative of using unsaved plans it even more painful (for

me).

</para>

</sect1>