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Search Results for: key_buffer_size value

Beware: key_buffer_size larger than 4G does not work

I was working with customer today which has MySQL on a system with some 64GB or RAM running MyISAM, so they set key_buffer_size to 16G… and every few days MySQL crashes. Why ? Because key_buffer_size …

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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 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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TokuDB vs InnoDB in timeseries INSERT benchmark

This post is a continuation of my research of TokuDB’s  storage engine to understand if it is suitable for timeseries workloads. While inserting LOAD DATA INFILE into an empty table shows great results for TokuDB, …

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Benchmarking Percona Server TokuDB vs InnoDB

After compiling Percona Server with TokuDB, of course I wanted to compare InnoDB performance vs TokuDB. I have a particular workload I’m interested in testing – it is an insert-intensive workload (which is TokuDB’s strong …

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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 …

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Predicting how long data load would take

I had this question asked many times during last week, and there is really no easy answer. There are just way too many variables to consider especially while loading large schemas with a lot of …

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What to tune in MySQL Server after installation

My favorite question during Interview for people to work as MySQL DBAs or be involved with MySQL Performance in some way is to ask them what should be tuned in MySQL Server straight after installation, …

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MySQL Server Variables – SQL layer or Storage Engine specific.

MySQL Server has tons of variables which may be adjusted to change behavior or for performance purposes. They are documented in the manual as well as on new page Jay has created. Still I see …

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MySQL Server Memory Usage

Every so often people ask me the question how should they estimate memory consumption by MySQL Server in given configuration. What is the formula they could use. The reasons to worry about memory usage are …

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