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Displaying posts with tag: foreign key constraints (reset)
Dropping Foreign Key constraint using pt-online-schema-change

Before we proceed, here is useful blog post  written by Peter on Hijacking Innodb Foreign Keys.

However, if you are trying to get rid of an unused Foreign Key (FK) constraint and related columns from versions older than mysql 5.6 or tables which cannot be executed with

ALTER TABLE ... ALGORITHM=INPLACE

  because of limitations mentioned here (specifically tables with 5.5 TIMESTAMP formats), you can use pt-online-schema-change  to drop such foreign keys.

For DROP FOREIGN KEY

constraint_name

  with  PT-OSC requires specifying

_constraint_name

  rather than the real

constraint_name …
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Advanced MySQL Query Tuning: Webinar followup Q&A

Thanks to all who attended my “MySQL Query Tuning” webinar on July 24.  If you missed it, you can you can download the slides and also watch the recorded video. Thank you for the excellent questions after the webinar as well. Query tuning is a big topic and, due to the limited time, I had to skip some material, especially some of the monitoring. I would like, however, to answer all the questions I did not get into during the webinar session.

Q: Did you reset the query cache before doing your benchmark on your query? 0.00 seconds sounds too good 

A: (This is in response to a …

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