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Search Results for: mysql index work

Advanced Query Tuning in MySQL 5.6 and MySQL 5.7 Webinar: Q&A

Thank you for attending my July 22 webinar titled “Advanced Query Tuning in MySQL 5.6 and 5.7” (my slides and a replay available here). As promised here is the list of questions and my answers …

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Find unused indexes on MongoDB and TokuMX

Finding and removing unused indexes is a pretty common technique to improve overall performance of relational databases. Less indexes means faster insert and updates but also less disk space used. The usual way to do …

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MySQL is crashing: a support engineer’s point of view

In MySQL QA Episode #12, “MySQL is Crashing, now what?,” Roel demonstrated how to collect crash-related information that will help Percona discover what the issue is that you are experiencing, and fix it. As a Support …

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MySQL replication primer with pt-table-checksum and pt-table-sync

MySQL replication is a process that allows you to easily maintain multiple copies of MySQL data by having them copied automatically from a master to a slave database. It’s essential to make sure the slave …

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The MySQL query cache: Worst enemy or best friend?

During the last couple of months I have been involved in an unusually high amount of performance audits for e-commerce applications running with Magento. And although the systems were quite different, they also had one …

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MySQL QA Episode 10: Reproducing and Simplifying: How to get it Right

Welcome to the 10th episode in the MySQL QA series! Today we’ll talk about reproducing and simplifying: How to get it Right. Note that unless you are a QA engineer stuck on a remote, and …

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MySQL QA Episode 4: QA Framework Setup Time!

Welcome to MySQL QA Episode 4! In this episode we’ll look into setting up our QA Framework: percona-qa, pquery, reducer & more. 1. All about percona-qa 2. pquery

3. reducer.sh

4. Short introduction to …

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Getting EXPLAIN information from already running queries in MySQL 5.7

When a new version of MySQL is about to be released we read a lot of blog posts about the performance and scalability improvements. That’s good but sometimes we miss some small features that can …

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Optimizer hints in MySQL 5.7.7 – The missed manual

In version MySQL 5.7.7 Oracle presented a new promising feature: optimizer hints. However it did not publish any documentation about the hints. The only note which I found in the user manual about the hints …

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Generated (Virtual) Columns in MySQL 5.7 (labs)

About 2 weeks ago Oracle published the MySQL 5.7.7-labs-json version which includes a very interesting feature called “Generated columns” (also know as Virtual or Computed columns). MariaDB has a similar feature as well: Virtual (Computed) Columns. The …

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