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Search Results for: select query using shell script

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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Increasing slow query performance with the parallel query execution

MySQL and Scaling-up (using more powerful hardware) was always a hot topic. Originally MySQL did not scale well with multiple CPUs; there were times when InnoDB performed poorer with more  CPU cores than with less CPU cores. …

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Using Multiple Key Caches for MyISAM Scalability

I have written before – MyISAM Does Not Scale, or it does quite well – two main things stopping you is table locks and global mutex on the KeyCache. Table Locks are not the issue …

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Using INFORMATION_SCHEMA instead of shell scripting

INFORMATION_SCHEMA, in particular by favorite TABLES table is not only helpful to understand tables you have on the system, but I have also found it to be very helpful as a scripting language for variety …

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MySQL Query Cache WhiteSpace and comments

Commenting on my previous post on MySQL Query Cache Gerry pokes me as I’m all wrong and both comments and whitespace are fixed in MySQL 5.0. This was not what I remember seeing in production …

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3 handy tools to remove problematic MySQL processes

DBAs often encounter situations where they need to kill queries to ensure there are no long-running queries on a MySQL server that would impact performance. Long-running queries can be the result of many factors. Fortunately, …

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ScaleArc: Real-world application testing with WordPress (benchmark test)

ScaleArc recently hired Percona to perform various tests on its database traffic management product. This post is the outcome of the benchmarks carried out by me and ScaleArc co-founder and chief architect, Uday Sawant. The …

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MySQL server memory usage troubleshooting tips

There are many blog posts already written on topics related to “MySQL server memory usage,” but nevertheless there are some who still get confused when troubleshooting issues associated with memory usage for MySQL. As a …

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MySQL 5.6 – InnoDB Memcached Plugin as a caching layer

A common practice to offload traffic from MySQL 5.6 is to use a caching layer to store expensive result sets or objects.  Some typical use cases include: Complicated query result set (search results, recent users, …

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Concatenating MyISAM files

Recently, I found myself involved in the migration of a large read-only InnoDB database to MyISAM (eventually packed). The only issue was that for one of the table, we were talking of 5 TB of …

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