Emergency

Search Results for: too many tables

MySQL Backup tools used by Percona Remote DBA for MySQL

As part of Percona Remote DBA for MySQL service we recognize that reliable backups are one of the most important things we can bring to the table. In my experience handling emergencies, the single worst …


Percona Toolkit 2.1 with New Online Schema Change Tool

I’m proud to announce the GA release of version 2.1 of Percona Toolkit. Percona Toolkit is the essential suite of administrative tools for MySQL. With this release we introduce a new version of pt-online-schema-change, a …


How FLUSH TABLES WITH READ LOCK works with Innodb Tables

Many backup tools including Percona Xtrabackup, MyLVMBackup and others use FLUSH TABLES WITH READ LOCK to temporary make MySQL read only. In many cases the period for which server has to be made read only …


Optimizing InnoDB for creating 30,000 tables (and nothing else)

Once upon a time, it would have been considered madness to even attempt to create 30,000 tables in InnoDB. That time is now a memory. We have customers with a lot more tables than a …


Lost innodb tables, xfs and binary grep

Before I start a story about the data recovery case I worked on yesterday, here’s a quick tip – having a database backup does not mean you can restore from it. Always verify your backup …


Replication of MEMORY (HEAP) Tables

Some Applications need to store some transient data which is frequently regenerated and MEMORY table look like a very good match for this sort of tasks. Unfortunately this will bite when you will be looking …


Tools

This page contains links to various tools we found helpful to use in practice. Some tools are written by us, others by third parties, yet another ones may be shipped with your operating system you …


The tool I’ve been waiting for years

I’ve just been pointed to the nice tool which I was waiting for years to see. It is fincore – little perl script which allows you to see what pages of file are cached in …


Using VIEW to reduce number of tables used

Many Open Source software solutions use database per user (or set of tables per user) which starts to cause problems if it is used on massive scale (blog hosting, forum hosting etc), resulting of hundreds …


How much overhead is caused by on disk temporary tables

As you might know while running GROUP BY and some other kinds of queries MySQL needs to create temporary tables, which can be created in memory, using MEMORY storage engine or can be created on …