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Search Results for: sort

[ERROR] mysqld: Sort aborted: Server shutdown in progress

Recently, one of our support customers faced this: “[ERROR] mysqld: Sort aborted: Server shutdown in progress.” At first it would appear this occurred because of a mysql restart (i.e. the MySQL server restarted and the …

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ALTER TABLE: Creating Index by Sort and Buffer Pool Size

Today I was looking at the ALTER TABLE performance with fast index creation and without it with different buffer pool sizes. Results are pretty interesting. I used modified Sysbench table for these tests because original …

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Building Indexes by Sorting In Innodb (AKA Fast Index Creation)

Innodb can indexes built by sort since Innodb Plugin for MySQL 5.1 which is a lot faster than building them through insertion, especially for tables much larger than memory and large uncorrelated indexes you might …

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Impact of the sort buffer size in MySQL

The parameter sort_buffer_size is one the MySQL parameters that is far from obvious to adjust. It is a per session buffer that is allocated every time it is needed. The problem with the sort buffer …

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Sorting a Terabyte in 197 seconds

Sorting a Terabyte in 197 seconds I just returned from The 21st ACM Symposium on Parallelism in Algorithms and Architectures (SPAA), held in Calgary, where I gave a talk about my entry to the sorting …

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What does Using filesort mean in MySQL?

If you were interviewing to work at Percona, and I asked you “what does Using filesort mean in EXPLAIN,” what would you say? I have asked this question in a bunch of interviews so far, …

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Possible optimization for sort_merge and UNION ORDER BY LIMIT

Every so often you need to perform sort results retrieved from MySQL when your WHERE clause goes beyound col=const values which would allow MySQL to still use second portion of the index for the order …

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How fast can you sort data with MySQL ?

I took the same table as I used for MySQL Group by Performance Tests to see how much MySQL can sort 1.000.000 rows, or rather return top 10 rows from sorted result set which is …

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ObjectRocket’s David Murphy talks about MongoDB, Percona Live Amsterdam

Say hello to David Murphy, lead DBA and MongoDB Master at ObjectRocket (a Rackspace company). David works on sharding, tool building, very large-scale issues and high-performance MongoDB architecture. Prior to ObjectRocket he was a MySQL/NoSQL …

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Advanced Query Tuning in MySQL 5.6 and MySQL 5.7 Webinar: Q&A

Thank you for attending my July 22 webinar titled “Advanced Query Tuning in MySQL 5.6 and 5.7” (my slides and a replay available here). As promised here is the list of questions and my answers …

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