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Search Results for: alter table table name

The MySQL ARCHIVE storage engine – Alternatives

In my previous post I pointed out that the existing ARCHIVE storage engine in MySQL may not be the one that will satisfy your needs when it comes to effectively storing large and/or old data. But …

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utf8 data on latin1 tables: converting to utf8 without downtime or double encoding

Here’s a problem some or most of us have encountered. You have a latin1 table defined like below, and your application is storing utf8 data to the column on a latin1 connection. Obviously, double encoding …

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MySQL alternative Percona Server 5.1.68 -14.6 now available

Percona is glad to announce the release of Percona Server  5.1.68 -14.6 on April 19, 2013 (downloads are available here and from the Percona Software Repositories). Based on MySQL 5.1.68, including all the bug fixes in it, Percona Server 5.1.68-14.6, a MySQL alternative, …

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MySQL optimizer: ANALYZE TABLE and Waiting for table flush

The MySQL optimizer makes the decision of what execution plan to use based on the information provided by the storage engines. That information is not accurate in some engines like InnoDB and they are based …

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Full table scan vs full index scan performance

Earlier this week, Cédric blogged about how easy we can get confused between a covering index and a full index scan in the EXPLAIN output. While a covering index (seen with EXPLAIN as Extra: Using …

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Why ALTER TABLE shows as two transactions in SHOW ENGINE INNODB STATUS

When executing an ALTER TABLE, InnoDB (and XtraDB) will create two InnoDB transactions: One transaction is created when the table being ALTERed is locked by the server. This will show up as something like “TABLE …

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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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On Character Sets and Disappearing Tables

The MySQL manual tells us that regardless of whether or not we use “SET FOREIGN_KEY_CHECKS=0” before making schema changes, InnoDB will not allow a column referenced by a foreign key constraint to be modified in …

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Using innodb_sys_tables and innodb_sys_indexes

I was playing with Percona Server today and found fast_index_creation does not work quite exactly like described in the manual. The point I’m looking to make though it would be very hard to catch this …

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Percona Server 5.5.11-20.2 Stable Release

Percona Server 5.5.11-20.2 is now available for download, including an experimental build for MacOS. Released on April 28, 2011, it is the current stable release in the the 5.5 series. New Features HandlerSocket, a NoSQL …

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