From cb3b3eda9a2a35a9ed2ad2eb97cd0355226499de Mon Sep 17 00:00:00 2001 From: Tom Lane <tgl@sss.pgh.pa.us> Date: Sun, 26 Mar 2000 01:00:17 +0000 Subject: [PATCH] In PQnotifies discussion, reference PQsocket as function needed to get file descriptor number for select(). (Suggestion from Ken Wright.) --- doc/src/sgml/libpq.sgml | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml index b700ce44975..c8cc2ee3e66 100644 --- a/doc/src/sgml/libpq.sgml +++ b/doc/src/sgml/libpq.sgml @@ -1460,13 +1460,17 @@ deprecated as a waste of processing power. <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> -- GitLab