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Search Results for: mysql sum from 3 queries

Tips from the trenches for over-extended MySQL DBAs

This post is a follow-up to my November 19 webinar, “Tips from the Trenches: A Guide to Preventing Downtime for the Over-Extended DBA,” during which I described some of the most common reasons DBAs experience …

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Schema changes in MySQL for OpenStack Trove users

People using OpenStack Trove instances can hit a common issue in the MySQL world: how to perform schema change operations while minimizing the impact on the database server? Let’s explore the options that can allow …

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How a set of queries can be killed in MySQL using Percona Toolkit’s pt-kill

You might have encountered situations where you had to kill some specific select queries that were running for long periods and choking the database. This post will go into more detail with an example of report …

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Data inconsistencies on MySQL replicas: Beyond pt-table-checksum

Percona Toolkit’s pt-table-checksum is a great tool to find data inconsistencies between a MySQL master and its replicas. However it is sometimes not enough to know that there are inconsistencies and let pt-table-sync fix the …

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How to close POODLE SSLv3 security flaw (CVE-2014-3566)

Padding Oracle On Downgraded Legacy Encryption First off, the naming “convention” as of late for security issues has been terrible. The newest vulnerability (CVE­-2014-3566) is nicknamed POODLE, which at least is an acronym and as per …

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How to avoid hash collisions when using MySQL’s CRC32 function

Percona Toolkit’s  pt-table-checksum performs an online replication consistency check by executing checksum queries on the master, which produces different results on replicas that are inconsistent with the master – and the tool pt-table-sync synchronizes data …

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MySQL Replication: ‘Got fatal error 1236’ causes and cures

MySQL replication is a core process for maintaining multiple copies of data – and replication is a very important aspect in database administration. In order to synchronize data between master and slaves you need to …

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Percona Toolkit 2.2.11 for MySQL is now available

Percona is pleased to announce the availability of Percona Toolkit 2.2.11.  Released on Sept. 25, Percona Toolkit is a collection of advanced command-line tools to perform a variety of MySQL server and system tasks that are too difficult or …

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MySQL upgrade best practices

MySQL upgrades are necessary tasks and we field a variety of questions here at Percona Support regarding MySQL upgrade best practices. This post highlights recommended ways to upgrade MySQL in different scenarios. Why are MySQL …

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MySQL 101: Monitor Disk I/O with pt-diskstats

Here on the Percona Support team we often ask customers to retrieve disk stats to monitor disk IO and to measure block devices iops and latency. There are a number of tools available to monitor …

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