<?xml version="1.0" encoding="UTF-8" standalone="no"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> <title>DB_ENV->set_mp_max_openfd()</title> <link rel="stylesheet" href="apiReference.css" type="text/css" /> <meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /> <link rel="start" href="index.html" title="Berkeley DB C API Reference" /> <link rel="up" href="memp.html" title="Chapter 8. The DB_MPOOLFILE Handle" /> <link rel="prev" href="envset_cachesize.html" title="DB_ENV->set_cachesize()" /> <link rel="next" href="mempset_mp_max_write.html" title="DB_ENV->set_mp_max_write()" /> </head> <body> <div xmlns="" class="navheader"> <div class="libver"> <p>Library Version 11.2.5.3</p> </div> <table width="100%" summary="Navigation header"> <tr> <th colspan="3" align="center">DB_ENV->set_mp_max_openfd()</th> </tr> <tr> <td width="20%" align="left"><a accesskey="p" href="envset_cachesize.html">Prev</a> </td> <th width="60%" align="center">Chapter 8. The DB_MPOOLFILE Handle </th> <td width="20%" align="right"> <a accesskey="n" href="mempset_mp_max_write.html">Next</a></td> </tr> </table> <hr /> </div> <div class="sect1" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h2 class="title" style="clear: both"><a id="mempset_mp_max_openfd"></a>DB_ENV->set_mp_max_openfd()</h2> </div> </div> </div> <pre class="programlisting">#include <db.h> int DB_ENV->set_mp_max_openfd(DB_ENV *env, int maxopenfd); </pre> <p> The <code class="methodname">DB_ENV->set_mp_max_openfd()</code> method limits the number of file descriptors the library will open concurrently when flushing dirty pages from the cache. </p> <p> The database environment's limit on open file descriptors to flush dirty pages may also be configured using the environment's <a href="../../programmer_reference/env_db_config.html#env_db_config.DB_CONFIG" class="olink">DB_CONFIG</a> file. The syntax of the entry in that file is a single line with the string "set_mp_max_openfd", one or more whitespace characters, and the number of open file descriptors. Because the <a href="../../programmer_reference/env_db_config.html#env_db_config.DB_CONFIG" class="olink">DB_CONFIG</a> file is read when the database environment is opened, it will silently overrule configuration done before that time. </p> <p> The <a class="xref" href="mempset_mp_max_openfd.html" title="DB_ENV->set_mp_max_openfd()">DB_ENV->set_mp_max_openfd()</a> method configures a database environment, not only operations performed using the specified <a class="link" href="env.html" title="Chapter 5. The DB_ENV Handle">DB_ENV</a> handle. </p> <p> The <code class="methodname">DB_ENV->set_mp_max_openfd()</code> <span> <span> method returns a non-zero error value on failure and 0 on success. </span> </span> </p> <div class="sect2" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h3 class="title"><a id="idp53336008"></a>Parameters</h3> </div> </div> </div> <div class="sect3" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h4 class="title"><a id="idp53354152"></a>maxopenfd</h4> </div> </div> </div> <p> The maximum number of file descriptors that may be concurrently opened by the library when flushing dirty pages from the cache. </p> </div> </div> <div class="sect2" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h3 class="title"><a id="idp53361896"></a>Errors</h3> </div> </div> </div> <p> The <code class="methodname">DB_ENV->set_mp_max_openfd()</code> <span> <span> method may fail and return one of the following non-zero errors: </span> </span> </p> <div class="sect3" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h4 class="title"><a id="idp53360016"></a>EINVAL</h4> </div> </div> </div> <p> An invalid flag value or parameter was specified. </p> </div> </div> <div class="sect2" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h3 class="title"><a id="idp53352728"></a>Class</h3> </div> </div> </div> <p> <a class="link" href="env.html" title="Chapter 5. The DB_ENV Handle">DB_ENV</a>, <a class="link" href="memp.html" title="Chapter 8. The DB_MPOOLFILE Handle">DB_MPOOLFILE</a> </p> </div> <div class="sect2" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h3 class="title"><a id="idp53365504"></a>See Also</h3> </div> </div> </div> <p> <a class="xref" href="memp.html#memplist" title="Memory Pools and Related Methods">Memory Pools and Related Methods</a> </p> </div> </div> <div class="navfooter"> <hr /> <table width="100%" summary="Navigation footer"> <tr> <td width="40%" align="left"><a accesskey="p" href="envset_cachesize.html">Prev</a> </td> <td width="20%" align="center"> <a accesskey="u" href="memp.html">Up</a> </td> <td width="40%" align="right"> <a accesskey="n" href="mempset_mp_max_write.html">Next</a></td> </tr> <tr> <td width="40%" align="left" valign="top">DB_ENV->set_cachesize() </td> <td width="20%" align="center"> <a accesskey="h" href="index.html">Home</a> </td> <td width="40%" align="right" valign="top"> DB_ENV->set_mp_max_write()</td> </tr> </table> </div> </body> </html>