<para>

A better way to check for NOTIFY

messages when you have no useful queries to make is to call

<function>PQconsumeInput()</function>, then check <function>PQnotifies()</function>.

<function>PQconsumeInput()</function>, then check

<function>PQnotifies()</function>.

You can use <function>select</function>(2) to wait for backend data to

arrive, thereby using no <acronym>CPU</acronym> power unless there is something

to do. Note that this will work OK whether you use <function>PQsendQuery</function>/

<function>PQgetResult</function> or simply <function>PQexec</function> for

queries. You should, however, remember to check <function>PQnotifies()</function>

after each <function>PQgetResult</function> or <function>PQexec</function> to see

to do. (See <function>PQsocket()</function> to obtain the file descriptor

number to use with <function>select</function>.)

Note that this will work OK whether you submit queries with

<function>PQsendQuery</function>/<function>PQgetResult</function> or simply

use <function>PQexec</function>. You should, however, remember to

check <function>PQnotifies()</function> after each

<function>PQgetResult</function> or <function>PQexec</function>, to see

if any notifications came in during the processing of the query.

</para>