<?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>Chapter 7. Performance tuning</title><meta name="generator" content="DocBook XSL Stylesheets V1.72.0" /><link rel="start" href="index.html" title="The Mutt E-Mail Client" /><link rel="up" href="index.html" title="The Mutt E-Mail Client" /><link rel="prev" href="optionalfeatures.html" title="Chapter 6. Optional features" /><link rel="next" href="reference.html" title="Chapter 8. Reference" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Chapter 7. Performance tuning</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="optionalfeatures.html">Prev</a> </td><th width="60%" align="center"> </th><td width="20%" align="right"> <a accesskey="n" href="reference.html">Next</a></td></tr></table><hr /></div><div class="chapter" lang="en" xml:lang="en"><div class="titlepage"><div><div><h2 class="title"><a id="tuning"></a>Chapter 7. Performance tuning</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="sect1"><a href="tuning.html#tuning-mailboxes">1. Reading and writing mailboxes</a></span></dt><dt><span class="sect1"><a href="tuning.html#tuning-messages">2. Reading messages from remote folders</a></span></dt><dt><span class="sect1"><a href="tuning.html#tuning-search">3. Searching and limiting</a></span></dt></dl></div><div class="sect1" lang="en" xml:lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="tuning-mailboxes"></a>1. Reading and writing mailboxes</h2></div></div></div><p> Mutt's performance when reading mailboxes can be improved in two ways: </p><p> </p><div class="orderedlist"><ol type="1"><li><p> For remote folders (IMAP and POP) as well as folders using one-file-per message storage (Maildir and MH), mutt's performance can be greatly improved using <a href="optionalfeatures.html#header-caching" title="7.1. Header caching">header caching</a>. Using a single database per folder may further increase performance. </p></li><li><p> Mutt provides the <a href="reference.html#read-inc" title="3.234. read_inc">$read_inc</a> and <a href="reference.html#write-inc" title="3.302. write_inc">$write_inc</a> variables to specify at which rate to update progress counters. If these values are too low, mutt may spend more time on updating the progress counter than it spends on actually reading/writing folders. </p><p> For example, when opening a maildir folder with a few thousand messages, the default value for <a href="reference.html#read-inc" title="3.234. read_inc">$read_inc</a> may be too low. It can be tuned on on a folder-basis using <a href="configuration.html#folder-hook" title="6. Setting variables based upon mailbox">folder-hooks</a>: </p><pre class="screen"> # use very high $read_inc to speed up reading hcache'd maildirs folder-hook . 'set read_inc=1000' # use lower value for reading slower remote IMAP folders folder-hook ^imap 'set read_inc=100' # use even lower value for reading even slower remote POP folders folder-hook ^pop 'set read_inc=1'</pre><p> </p></li></ol></div><p> </p></div><div class="sect1" lang="en" xml:lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="tuning-messages"></a>2. Reading messages from remote folders</h2></div></div></div><p> Reading messages from remote folders such as IMAP an POP can be slow especially for large mailboxes since mutt only caches a very limited number of recently viewed messages (usually 10) per session (so that it will be gone for the next session.) </p><p> To improve performance and permanently cache whole messages, please refer to mutt's so-called <a href="optionalfeatures.html#body-caching" title="7.2. Body caching">body caching</a> for details. </p></div><div class="sect1" lang="en" xml:lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="tuning-search"></a>3. Searching and limiting</h2></div></div></div><p> When searching mailboxes either via a search or a limit action, for some patterns mutt distinguishes between regular expression and string searches. For regular expressions, patterns are prefixed with ``˜'' and with ``='' for string searches. </p><p> Even though a regular expression search is fast, it's several times slower than a pure string search which is noticable especially on large folders. As a consequence, a string search should be used instead of a regular expression search if the user already knows enough about the search pattern. </p><p> For example, when limiting a large folder to all messages sent to or by an author, it's much faster to search for the initial part of an e-mail address via <code class="literal">=Luser@</code> instead of <code class="literal">˜Luser@</code>. This is especially true for searching message bodies since a larger amount of input has to be searched. </p><p> Please note that string search is an exact case-sensitive search while a regular expression search with only lower-case letters performs a case-insensitive search. </p></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="optionalfeatures.html">Prev</a> </td><td width="20%" align="center"> </td><td width="40%" align="right"> <a accesskey="n" href="reference.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Chapter 6. Optional features </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> Chapter 8. Reference</td></tr></table></div></body></html>