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Search Results for: innodb concurrency problems

Concurrency Improvements in TokuDB v6.6 (Part 2)

In Part 1, we showed performance results of some of the work that’s gone in to TokuDB v6.6. In this post, we’ll take a closer look at how this happened, on the engineering side, and …

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thread_concurrency doesn’t do what you expect

Over the last months I’ve seen lots of customers trying to tune the thread concurrency inside MySQL with the variable thread_concurrency. Our advice is: stop wasting your time, it does nothing on GNU/Linux Some of …

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InnoDB’s gap locks

One of the most important features of InnoDB is the row level locking. This feature provides better concurrency under heavy write load but needs additional precautions to avoid phantom reads and to get a consistent …

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Avoiding auto-increment holes on InnoDB with INSERT IGNORE

Are you using InnoDB tables on MySQL version 5.1.22 or newer? If so, you probably have gaps in your auto-increment columns. A simple INSERT IGNORE query creates gaps for every ignored insert, but this is …

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Fix of InnoDB/XtraDB scalability of rollback segment

Recently I wrote about InnoDB scalability on 24-core box, and we made research of scalability problems in sysbench write workload (benchmark emulates intensive insert/delete queries). By our results the problem is in concurrency on rollback …

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Should you move from MyISAM to Innodb ?

There is significant portion of customers which are still using MyISAM when they come to us, so one of the big questions is when it is feasible to move to Innodb and when staying on …

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Heikki Tuuri answers to Innodb questions, Part II

I now got answers to the second portions of the questions you asked Heikki. If you have not seen the first part it can be found here. Same as during last time I will provide …

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Heikki Tuuri Innodb answers – Part I

Its almost a month since I promised Heikki Tuuri to answer Innodb Questions. Heikki is a busy man so I got answers to only some of the questions but as people still poking me about …

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MySQL Users Conference – Innodb

It might look like it is too late to write about stuff happened at Users Conference but I’m just starting find bits of time from processing accumulated backlog. The Theme of this Users Conference was …

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InnoDB benchmarks

There was several changes in InnoDB to fix scalabilty problems, so I ran benchmark to check new results and also compare overall performance of InnoDB in 5.0 and 5.1 before and after fixes. Problems in …

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