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Search Results for: count number of row deleted by delete query

Identifying useful info from MySQL row-based binary logs

As a MySQL DBA/consultant, it is part of my job to decode the MySQL binary logs – and there are a number of reasons for doing that. In this post, I’ll explain how you can …

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Recovery deleted ibdata1

Recently I had a case when a customer deleted the InnoDB main table space – ibdata1 – and redo logs – ib_logfile*. MySQL keeps InnoDB files open all the time. The following recovery technique is …

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Flexviews – part 3 – improving query performance using materialized views

Combating “data drift” In my first post in this series, I described materialized views (MVs). An MV is essentially a cached result set at one point in time. The contents of the MV will become …

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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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‘Indexing’ JSON documents for efficient MySQL queries over JSON data

MySQL meets NoSQL with JSON UDF I recently got back from FOSDEM, in Brussels, Belgium. While I was there I got to see a great talk by Sveta Smirnova, about her MySQL 5.7 Labs release …

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Innodb transaction history often hides dangerous ‘debt’

In many write-intensive workloads Innodb/XtraDB storage engines you may see hidden and dangerous “debt” being accumulated – unpurged transaction “history” which if not kept in check over time will cause serve performance regression or will …

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Q&A: Even More Deadly Mistakes of MySQL Development

On Wednesday I gave a presentation on “How to Avoid Even More Common (but Deadly) MySQL Development Mistakes” for Percona MySQL Webinars.  If you missed it, you can still register to view the recording and my slides. Thanks …

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Using MySQL 5.6 Performance Schema in multi-tenant environments

Hosting a shared MySQL instance for your internal or external clients (“multi-tenant”) was always a challenge. Multi-tenants approach or a “schema-per-customer” approach is pretty common nowadays to host multiple clients on the same MySQL sever. One of …

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How to monitor ALTER TABLE progress in MySQL

While working on a recent support issue as a Percona Support Engineer,  I got one question from a customer asking how to monitor ALTER TABLE progress. Actually, for MySQL 5.5 and prior versions, it’s quite difficult to ALTER the …

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How to recover an orphaned .ibd file with MySQL 5.6

A few years ago Yves Trudeau and Aleksandr Kuzminsky wrote posts about different ways for recovering orphaned .ibd files: Connecting orphaned .ibd files A recovery trivia or how to recover from a lost ibdata1 file …

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