InnoDB
Q: Does MySQL support ACID? A: Yes
I was recently asked this question by an experienced academic at the NY Oracle Users Group event I presented at. Does MySQL support ACID? (ACID is a set of properties essential for a relational database to perform transactions , i.
Read moreWhat is FTS_BEING_DELETED.ibd
I currently have on a MySQL 5.6 database using innodb_file_per_table the following individual tablespace file. schema/FTS_00000000000001bb_BEING_DELETED.ibd The schema is all InnoDB tables, and there ARE NO Full Text Indexes. I cannot comment on if a developer has tried to create one previously.
Read moreSQL_MODE and storage engines
I was again reminded why setting SQL_MODE is so important in any new MySQL environment. While performing benchmark tests on parallel backup features with a common InnoDB tablespace and per file tablespace, I inadvertently missed an important step in the data migration.
Read moreLeveraging the InnoDB Plugin
Beginning with MySQL 5.1 as an additional plugin and included by default in MySQL 5.5 the InnoDB plugin includes many performance improvements. To leverage the support of new file formats however a very important setting is necessary.
Read moreFive reasons to upgrade to MySQL 5.5
Updated Nov 2011. Check out my Reasons to use MySQL 5.5 Presentation for more in-depth information about installing/configuring and using MySQL 5.5 I have been looking forward to the general availability (GA) release of MySQL 5.
Read moreMySQL 5.5 and transaction management
Announced at MySQL Sunday was the Release Candidate edition of MySQL 5.5.6. Also noted by Geert where he points out the default storage engine is now InnoDB. However, for those from a background other then MySQL there is still a gotcha.
Read more10x Performance Improvements in MySQL – A Case Study
The slides for my presentation at FOSDEM 2010 are now available online at slideshare . In this presentation I describe a successful client implementation with the result of 10x performance improvements.
Read moreCalculating your database size
I generally use the following MySQL INFORMATION_SCHEMA (I_S) query to Calculate Your MySQL Database Size . This query and most others that access the MySQL INFORMATION_SCHEMA can be very slow to execute because they are not real tables and are not governed by physical data, memory buffers and indexes for example but rather internal MySQL data structures.
Read moreUnderstanding Innodb Transaction Isolation
The MySQL Innodb storage engine provides ACID compliance, the ‘I’ being isolation. There are four states defined in MySQL with the tx_isolation system variable, READ-UNCOMMITTED, READ-COMMITTED, REPEATABLE-READ and SERIALIZABLE. Generally MySQL installations do not modify the default value of tx_isolation = REPEATABLE-READ, however I have seen with a number of clients the default value has been changed to READ-COMMITTED.
Read moreMy favorite MySQL data type – DECIMAL(31,0)
It may seem hard to believe, but I have seen DECIMAL(31,0) in action on a production server. Not just in one column, but in 15 columns just in the largest 4 tables of one schema.
Read moreInnoDB I_S.tables.table_rows out by a factor of 100x
I’ve always believed that the MySQL Information_schema.tables.table_rows figure for Innodb tables to be while approximate, approximately accurate. Today I found that the figures varied on one table from 10x to 100x wrong.
Read moreSetting up sysbench with MySQL & Drizzle
Sysbench is a open source product that enables you to perform various system benchmarks including databases. Drizzles performs regression testing of every trunk revision with a branched version of sysbench within Drizzle Automation .
Read moreUnderstanding InnoDB MVCC
Multi versioning concurrency control (MVCC) is a database design theory that enables relational databases to support concurrency, or more simply multiple user access to common data in your database. In MySQL the InnoDB storage engine provides MVCC, row-level locking, full ACID compliance as well as other features.
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