</screen>

</para>

<note>

<para>

The entire body of a SQL function is parsed before any of it is

executed. While a SQL function can contain commands that alter

the system catalogs (e.g., <command>CREATE TABLE</>), the effects

of such commands will not be visible during parse analysis of

later commands in the function. Thus, for example,

<literal>CREATE TABLE foo (...); INSERT INTO foo VALUES(...);</literal>

will not work as desired if packaged up into a single SQL function,

since <structname>foo</> won't exist yet when the <command>INSERT</>

command is parsed. It's recommended to use <application>PL/PgSQL</>

instead of a SQL function in this type of situation.

</para>

</note>

<para>

The syntax of the <command>CREATE FUNCTION</command> command requires

the function body to be written as a string constant. It is usually