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    <p>That <code>ibdata1</code> isn't shrinking is a particularly annoying feature of MySQL. The <code>ibdata1</code> file can't actually be shrunk unless you delete all databases, remove the files and reload a dump.</p> <p>But you can configure MySQL so that each table, including its indexes, is stored as a separate file. In that way <code>ibdata1</code> will not grow as large. According to <a href="https://stackoverflow.com/questions/3456159/how-to-shrink-purge-ibdata1-file-in-mysql#comment25251583_3456885">Bill Karwin's comment</a> this is enabled by default as of version 5.6.6 of MySQL.</p> <p>It was a while ago I did this. However, to setup your server to use separate files for each table you need to change <code>my.cnf</code> in order to enable this:</p> <pre><code>[mysqld] innodb_file_per_table=1 </code></pre> <p><a href="http://dev.mysql.com/doc/refman/5.5/en/innodb-multiple-tablespaces.html" rel="noreferrer">http://dev.mysql.com/doc/refman/5.5/en/innodb-multiple-tablespaces.html</a></p> <p>As you want to reclaim the space from <code>ibdata1</code> you actually have to delete the file:</p> <ol> <li>Do a <code>mysqldump</code> of all databases, procedures, triggers etc <strong>except the <code>mysql</code> and <code>performance_schema</code> databases</strong></li> <li>Drop all databases <strong>except the above 2 databases</strong></li> <li>Stop mysql</li> <li>Delete <code>ibdata1</code> and <code>ib_log</code> files</li> <li>Start mysql</li> <li>Restore from dump</li> </ol> <p>When you start MySQL in step 5 the <code>ibdata1</code> and <code>ib_log</code> files will be recreated. </p> <p>Now you're fit to go. When you create a new database for analysis, the tables will be located in separate <code>ibd*</code> files, not in <code>ibdata1</code>. As you usually drop the database soon after, the <code>ibd*</code> files will be deleted. </p> <p><a href="http://dev.mysql.com/doc/refman/5.1/en/drop-database.html" rel="noreferrer">http://dev.mysql.com/doc/refman/5.1/en/drop-database.html</a></p> <p>You have probably seen this:<br> <a href="http://bugs.mysql.com/bug.php?id=1341" rel="noreferrer">http://bugs.mysql.com/bug.php?id=1341</a></p> <p>By using the command <code>ALTER TABLE &lt;tablename&gt; ENGINE=innodb</code> or <code>OPTIMIZE TABLE &lt;tablename&gt;</code> one can extract data and index pages from ibdata1 to separate files. However, ibdata1 will not shrink unless you do the steps above.</p> <p>Regarding the <code>information_schema</code>, that is not necessary nor possible to drop. It is in fact just a bunch of read-only views, not tables. And there are no files associated with the them, not even a database directory. The <code>informations_schema</code> is using the memory db-engine and is dropped and regenerated upon stop/restart of mysqld. See <a href="https://dev.mysql.com/doc/refman/5.7/en/information-schema.html" rel="noreferrer">https://dev.mysql.com/doc/refman/5.7/en/information-schema.html</a>.</p>
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    1. POHow to shrink/purge ibdata1 file in MySQL
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    1. USJohn P
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    1. COThere's no need for the "=1" according to http://dev.mysql.com/doc/refman/5.1/en/innodb-multiple-tablespaces.html
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    2. COWhat about information_schema and performance_schema?
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      1. USJordan Magnuson
    3. CO@JordanMagnuson I tried that on a test server, it wouldn't let me (logged in as the mysql root/admin user) drop information_schema. So, no.
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