# Downgrade to Percona 5.5

**URL:** <https://forums.percona.com/t/downgrade-to-percona-5-5/3007>\
**Category:** Other MySQL® Questions\
**Created:** [October 14, 2013, 8:55am UTC](https://forums.percona.com/t/downgrade-to-percona-5-5/3007 "2013-10-14T08:55:20Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![matt1206](https://avatars.discourse-cdn.com/v4/letter/m/e9a140/32.png) [@matt1206](https://forums.percona.com/u/matt1206)\
**Post date:** [October 14, 2013, 8:55am UTC](https://forums.percona.com/t/downgrade-to-percona-5-5/3007/1 "2013-10-14T08:55:20Z")

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Hi All,

I had to downgrade from Percona 5.6 back to 5.5 as I couldn’t get it to work with Cpanel (php wouldn’t compile and apache wouldn’t start with 5.6 installed). Running CentOS6.4 and Percona installed / upgraded via YUM.

Percona-Server-test-55-5.5.33-rel31.1.566.rhel6.x86\_64  
Percona-Server-devel-55-5.5.33-rel31.1.566.rhel6.x86\_64  
Percona-Server-server-55-5.5.33-rel31.1.566.rhel6.x86\_64  
Percona-Server-client-55-5.5.33-rel31.1.566.rhel6.x86\_64  
Percona-Server-shared-55-5.5.33-rel31.1.566.rhel6.x86\_64  
Percona-Server-shared-compat-5.5.33-rel31.1.566.rhel6.x86\_64

Now, after downgrading, I’m getting a few errors relating to tables in the mysql database that were created during the upgrade process.

I’ve tried searching, and can’t find any information on this problem yet.

I managed to fix the issue with procs\_priv.frm, general\_log.frm and slow\_log.frm by copying the .frm file over from another installation of 5.5, but I can’t seem to so anything with the other errors.

The only thing I’ve found relating to these tables is here : [URL][innodb - Cannot open table mysql/innodb\_index\_stats - Database Administrators Stack Exchange](http://dba.stackexchange.com/questions/48166/cannot-open-table-mysql-innodb-index-stats%5B/URL%5D)

Is it possible to drop those tables from the database if they aren’t needed in 5.5?

Thanks,  
Matt

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<div class="post-metadata">

**Author:** ![niljoshi](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/niljoshi/32/16889_2.png) [@niljoshi](https://forums.percona.com/u/niljoshi)\
**Post date:** [October 16, 2013, 2:39am UTC](https://forums.percona.com/t/downgrade-to-percona-5-5/3007/2 "2013-10-16T02:39:07Z")

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Hi,

I hope you know that while downgrade to 5.5, we need to check below things.  
[URL][https://dev.mysql.com/doc/refman/5.6/en/downgrading.html[/URL]](https://dev.mysql.com/doc/refman/5.6/en/downgrading.html%5B/URL%5D)

Have you run mysql\_upgrade after downgrade to 5.5? If not that I would suggest to do it and let us know if you still face the same issue.