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Displaying posts with tag: MySQL (reset)
WebScaleSQL builds available for Debian 8 and Ubuntu 15.04

After many months of heavy development and testing, Debian 8 (Jesse) and Ubuntu 15.04 (Vivid Vervet) were released recently.

For those who already upgraded their systems and/or plan do do it in close future, we prepared builds of WebScaleSQL :-)

You can also install it using PSCE repository.

 

Indexing 101: Optimizing MySQL queries on a single table

I have recently seen several cases when performance for MySQL queries on a single table was terrible. The reason was simple: the wrong indexes were added and so the execution plan was poor. Here are guidelines to help you optimize various kinds of single-table queries.

Disclaimer: I will be presenting general guidelines and I do not intend to cover all scenarios. I am pretty confident that you can find examples where what I am writing does not work, but I am also confident that it will help you most of the time. Also I will not discuss features you can find in MySQL 5.6+ like Index Condition Pushdown to keep things simple. Be aware that such features can actually make a significant difference in query response time (for good or for bad).

What an index can do for you

An index can perform up to 3 actions: filter, sort/group and cover. While the first 2 actions are self-explanatory, not everyone may know what …

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Slides from the MySQL Session at Great Indian developer Summit 2015

Wanted to send a pointer to the slides from my session at #GIDS 2015.

Will followup with an impressions blog soon.

My sql5.7 whatsnew_presentedatgids2015 from Sanjay Manwani

MySQL Workbench 6.3.3 GA has been released

The MySQL developer tools team is pleased to announce 6.3.3 as our GA release for the MySQL Workbench 6.3

For the full list of changes in this revision, visit

http://dev.mysql.com/doc/relnotes/workbench/en/changes-6-3.html

For detailed information about the new features, see What’s
New in MySQL Workbench 6.3
http://dev.mysql.com/doc/workbench/en/wb-what-is-new-63.html

For discussion, join the MySQL Workbench Forums:
http://forums.mysql.com/index.php?151

Download MySQL Workbench 6.3.3 GA now, for Windows, Mac OS X 10.7+,
Oracle Linux 6 and 7, Fedora 20 and Fedora 21, Ubuntu 14.04 and Ubuntu
14.10 …

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Happy to see this MySQL JSON momentum !

Last week at Percona Live Facebook has presented for the first time Docstore which is a native JSON implementation in MySQL. Oracle has also presented their MySQL 5.7 lab release that includes the implementation of a native JSON type. This is an important move as MySQL was behind other other RDMS regarding JSON (PostgreSQL already [...]

MySQL OCP Exams

Planning out my year, I decided to take the Oracle OCP and MySQL OCP exams. I checked for review books and was pleasantly surprised to find the soon to be released OCP MySQL Database Administrator Exam Guide (Exam 1Z0-883). However, I noticed that the book was actually prepared for the obsolete and discountinued Exams 1Z0-870, 1Z0-873, and 1Z0-874. As it turns out, Steve O’Hearn has informed me that there isn’t a book and that the posting in Amazon.com is in error.

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Getting familiar with TokuDB part 2.

Last time I was checked, how can TokuDB be used as a drop in replacement of InnoDB. The first impressions were jolly good; way less disk space usage, and the TokuDB host can be a part of the current replication cluster.

So far so good.

Well, actually not everything is that nice, because there is a very big part of infrastructure is built on the top of xtrabackup.

So let’s see what can we do backing up TokuDB.

The first and most clean way should be the mysqldump utility, but sadly this is not really useful for us, the restore process could be take too many time, because a lot of indexes has to be rebuilt.

So we need to take binary backups. Sadly TokuDB currently offers only tokudbhotbackup for hot backup which is a part of the enterprise feature set. Sadly that seems not opensource (yet!), but I hope Percona will change that soon.

Until that the following things are sure: xtrabackup cannot …

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MySQL Enterprise Database Firewall — Control and Monitor SQL Statement Executions

As of MySQL 5.6.24, MySQL Enterprise Edition includes MySQL Enterprise Firewall, an application-level firewall (it runs within the mysql database process) that enables database administrators to permit or deny SQL statement execution based on matching against whitelists of accepted statement patterns. This helps harden MySQL Server against attacks such as SQL injection or attempts to exploit applications by using them outside of their legitimate query workload characteristics.

Each MySQL account registered with the firewall has its own whitelist of statement patterns (a tokenized representation of a SQL statement), enabling protection to be tailored per account. For a given account, the firewall can operate in recording or protecting mode, for training in the accepted statement …

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MariaDB : Bug when add index on Partition table

Version: 5.5.5-10.0.10-MariaDB-log MariaDB Server

When I use mariadb as multi-source slave DB I met a strange problem . Creating index on a vary large partition table , Mariadb do — copy to tmp table on the slave side. It takes a long time and still not finish over 9 hours.

Primary : MySQL 5.6.16 —

add index on a partition table:

CREATE TABLE `track_raw_wap211_log` (
 `table_id` varchar(100) DEFAULT NULL,
 `page_id` varchar(100) DEFAULT NULL,
 `banner_id` varchar(100) DEFAULT NULL,
 `button_id` varchar(100) DEFAULT NULL,
 `test_id` varchar(100) DEFAULT NULL,
 `classfication` varchar(100) DEFAULT NULL,
 `request_refer` varchar(100) DEFAULT NULL,
 `request_url` text,
 `title` varchar(100) DEFAULT NULL,
 `user_id` varchar(100) DEFAULT NULL,
 `language` varchar(100) DEFAULT NULL,
 `event` varchar(100) DEFAULT NULL,
 `event_desc` varchar(100) DEFAULT NULL,
 `event_type` varchar(100) DEFAULT NULL,
 `log_version` varchar(100) DEFAULT …
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Breakpoints for stored procedures and functions

and without creating a table to pass the state around (really just an excuse to use the named locks feature).

DELIMITER //
DROP FUNCTION IF EXISTS SET_BREAKPOINT//
CREATE FUNCTION SET_BREAKPOINT()
RETURNS tinyint
NO SQL
BEGIN
        -- Acquire lock 1
        -- Wait until lock 2 is taken to signal that we may continue
        DO GET_LOCK(CONCAT('lock_1_', CONNECTION_ID()), -1);
        REPEAT
                DO 1;
        UNTIL IS_USED_LOCK(CONCAT('lock_2_', CONNECTION_ID())) END REPEAT;
        DO RELEASE_LOCK(CONCAT('lock_1_', CONNECTION_ID()));

        -- Acquire lock 3 to acknowledge message to continue.
        -- Wait for lock 2 to be released as signal of receipt.
        DO GET_LOCK(CONCAT('lock_3_', CONNECTION_ID()), -1);
        REPEAT
                DO 1;
        UNTIL IS_FREE_LOCK(CONCAT('lock_2_', CONNECTION_ID())) END REPEAT;
        DO RELEASE_LOCK(CONCAT('lock_3_', CONNECTION_ID()));

        RETURN 1;
END//

DROP FUNCTION IF EXISTS …
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