Post: Migrating to XtraDB Cluster Webinar follow up questions
…two Percona server node as Master-Master ? You can write to any of the nodes in the cluster in…to fix yourself as well. Q: what about humongous ALTER TABLE? Does it run one at a time in…bottlenecks in...
View ArticlePost: Find unused indexes
…how to find duplicate indexes. This time we’ll learn how to find unused indexes to…mysql. After some runs we can start to analyze the information on INDEX_STATISTICS table. mysql> SELECT * FROM...
View ArticlePost: How to load large files safely into InnoDB with LOAD DATA INFILE
…ALTER TABLE in 10k row chunks, by the way; I chose 1M because the rows were small). But how to…file in one chunk: time mysql -e …to a file. To load the file in chunks, I split my screen session in two...
View ArticlePost: High-Performance Click Analysis with MySQL
…to measure the ad’s value? Is it enough to know how many times…to use InnoDB/XtraDB tables… Optimize For I/O It is pretty much inevitable: if you do this kind of data processing in MySQL…ALTER TABLE...
View ArticlePost: Using MMM to ALTER huge tables
…to share my experience. The article does not cover MMM installation nor how to…to db1 at this stage. If you’re altering gigabyte size tables, this step may take some time… The post Post: Using MMM to...
View ArticlePost: The Optimization That (Often) Isn't: Index Merge Intersection
…two…times, it is a major performance killer. It’s fairly straightforward to tell when MySQL…to go mucking about with server configuration, altering the table structure, or creating messy sub-selects....
View ArticlePost: Percona Toolkit Webinar followup Q&A
…How to make the tools connect to MySQL The slides are now available here, and slide 7 provides a basic introduction to…table at a time, and processes each table one chunk at a time, checksumming each...
View ArticlePost: Quickly finding unused indexes (and estimating their size)
…two tables: mysql> create view used_indexes as (select TABLE_SCHEMA, TABLE_NAME, INDEX_NAME from master_index_stats ) UNION DISTINCT (select TABLE_SCHEMA, TABLE…table by simply doing: mysql>...
View ArticlePost: Implications of Metadata Locking Changes in MySQL 5.5
…how the query spent nearly all its time waiting in the “Opening tables” state. Now this behavior with respect to ALTER making the table inaccessible in some cases is not really documented and as such...
View ArticlePost: InnoDB Full-text Search in MySQL 5.6 (part 1)
…to find out how to make InnoDB FTS blazingly-fast, but simply to get a sense of how it works compared to…ALTER TABLE statement, but it’s not possible to CREATE more than one at a time. If you try it,...
View ArticlePost: InnoDB Full-text Search in MySQL 5.6: Part 2, The Queries!
…in MySQL 5.6: Part 2, The Queries![/caption] This is part 2 in a 3 part series. In…to 5.6 and running ALTER TABLE foo ENGINE=InnoDB. In theory, yes. In practice, not even close. I tried one more...
View ArticlePost: Beware of MySQL Data Truncation
…in set (0.00 sec) For table “article” itself you would notice the issue quickly if you would forget to alter…how to avoid this problem ? It is actually quite easy – you just need to enable strict...
View ArticlePost: How Percona does a MySQL Performance Audit
…times, etc), the EXPLAIN plan, and the desired modifications to the query or the table. We explain how to…The post Post: How Percona does a MySQL Performance Audit appeared first on MySQL Performance...
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Quickly finding unused indexes (and estimating their size)
I had a customer recently who needed to reduce their database size on disk quickly without a lot of messy schema redesign and application recoding. They didn’t want to drop any actual data, and their...
View ArticleThe Optimization That (Often) Isn’t: Index Merge Intersection
Prior to version 5.0, MySQL could only use one index per table in a given query without any exceptions; folks that didn’t understand this limitation would often have tables with lots of single-column...
View ArticlePercona Toolkit Webinar followup Q&A
First, a thank you to everyone who attended the webinar Today, I appreciate your time and nice comments. As promised, here are answers to questions that couldn’t be answered during the talk: Q: How do...
View ArticleRead/Write Splitting with PHP Webinar Questions Followup
Today I gave a presentation on “Read/Write Splitting with PHP” for Percona Webinars. If you missed it, you can still register to view the recording and my slides.Thanks to everyone who attended, and...
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Percona Server on the Raspberry Pi: Your own MySQL Database Server for Under $80
There are many reasons for wanting a small MySQL database server:You’re a uni student who wants to learn the SQL language better and needs a mini-testboxYou’re a Windows user who wants to play around...
View ArticleMySQL 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...
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MySQL Backup tools used by Percona Remote DBA for MySQL
As part of Percona Remote DBA for MySQL service we recognize that reliable backups are one of the most important things we can bring to the table. In my experience handling emergencies, the single...
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