# Altering table in mysql using pt-online-schema-change with triggers

**URL:** <https://forums.percona.com/t/altering-table-in-mysql-using-pt-online-schema-change-with-triggers/17906>\
**Category:** Percona Toolkit\
**Created:** [October 7, 2022, 3:35pm UTC](https://forums.percona.com/t/altering-table-in-mysql-using-pt-online-schema-change-with-triggers/17906 "2022-10-07T15:35:27Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Dba1](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/dba1/32/24223_2.png) [@Dba1](https://forums.percona.com/u/Dba1)\
**Post date:** [October 7, 2022, 3:35pm UTC](https://forums.percona.com/t/altering-table-in-mysql-using-pt-online-schema-change-with-triggers/17906/1 "2022-10-07T15:35:27Z")

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I am using a pt-online-schema change to alter a table and its column from smallint to mediumint. There is a trigger on the table I have read the documentation. During my dry -run I encountered “there is a trigger on the table but —preserve triggers was not specified. Does it mean or-online -schema change can work even with the trigger in the table?  
Where do I put the condition in the syntax in-case it works.

Note forgive my wordings any errors in typos and English please forgive

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<div class="post-metadata">

**Author:** ![Dba1](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/dba1/32/24223_2.png) [@Dba1](https://forums.percona.com/u/Dba1)\
**Post date:** [October 7, 2022, 3:40pm UTC](https://forums.percona.com/t/altering-table-in-mysql-using-pt-online-schema-change-with-triggers/17906/2 "2022-10-07T15:40:07Z")

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Thank you guys.I just solved it never mind it works. Kudos. I put the —preserve -triggers before the t, And D. Works great