Planet MySQL Planet MySQL: Meta Deutsch Español Français Italiano 日本語 Русский Português 中文
10 Newer Entries Showing entries 31 to 40 of 196 10 Older Entries

Displaying posts with tag: MySQL 5.6 (reset)

Faking a slave: Subscribing to mysql row-based-replication changes
Employee +0 Vote Up -1Vote Down

In complex systems it's often useful to be able to receive notification when rows have been modified in MySQL so that you can invalidate various external caches or indexes. For example: memcached, Sphinx, Lucene.

In the case of MySQL's default statement-based replication this can be quite tricky to do, as it would likely require an SQL parser to determine what was intended to be modified. However, this is made much simpler with Row-based Replication (something I recommend switching to).

A …

  [Read more...]
Batch mode and expired passwords
Employee +3 Vote Up -0Vote Down

A series of related discussions triggered by difficulty in setting passwords via scripts using the mysql command-line client when an account has an expired password caused me to look into the interaction between expired passwords and batch mode, and this blog post resulted.  I …

  [Read more...]
GTIDs in MySQL 5.6: New replication protocol; new ways to break replication
+1 Vote Up -0Vote Down

One of the MySQL 5.6 features many people are interested in is Global Transactions IDs (GTIDs). This is for a good reason: Reconnecting a slave to a new master has always been a challenge while it is so trivial when GTIDs are enabled. However, using GTIDs is not only about replacing good old binlog file/position with unique identifiers, it is also using a new replication protocol. And if you are not aware of it, it can bite.

Replication protocols: old vs new

The old protocol is pretty …

  [Read more...]
MySQL 5.6 + GTID & MariaDB 10 replication
+1 Vote Up -0Vote Down

While at the keynote of Tomas Ulin at Percona Live MySQL Conference & Expo Santa Clara 2014, he asked the audience what they were running, and most of the audience was on MySQL 5.5 while about 15% of the audience was on MySQL 5.6. This number is steadily increasing I’m sure, so one thing that becomes important is that people will probably start turning on Global Transaction Identifiers (GTIDs).  …

  [Read more...]
MySQL 5.6.17 Overview and Highlights
+1 Vote Up -0Vote Down

MySQL 5.6.17 was recently released (it is the latest MySQL 5.6, is GA), and is available for download here:

For this release, I counted 7 “Functionality Added” and/or “Incompatible Change” fixes:

  1. Incompatible Change: The AES_ENCRYPT() and AES_DECRYPT() functions now permit control of the block encryption mode and take an optional initialization vector argument.
  2. Incompatible Change: The ERROR_FOR_DIVISION_BY_ZERO, …
  [Read more...]
MySQL 5.6.17 – now with better encryption
Employee +1 Vote Up -0Vote Down

Joro wrote recently about MySQL 5.6.17‘s new support for AES-256 encryption, and it’s a great improvement for people need to encrypt their data at rest.  The new session block_encryption_mode variable controls what variant of AES is used, and for backwards compatibility, the default behavior remains 128-bit key …

  [Read more...]
MySQL 5.6 Certification Now GA!
Employee +3 Vote Up -0Vote Down

The MySQL 5.6 certification exams (Developer and DBA) are now GA!  A big thanks to all those who sat for the extended length beta exams – and subsequently waited for several months for your results.  Your feedback and the …

  [Read more...]
Many-table joins in MySQL 5.6
+3 Vote Up -0Vote Down

I recently worked on an uncommon slow query: less than 100 rows were read and returned, the whole dataset was fitting in memory but the query took several seconds to run. Long story short: the query was a join involving 21 tables, running on MySQL 5.1. But by default MySQL 5.1 is not good at handling joins with such a large number of tables. The good news is that MySQL 5.6 brings welcome improvements.

Isolating the problem

As always with a slow query, finding the execution plan with EXPLAIN is the 1st step to understand where time is spent. Here the plan was very good with almost all joins using the primary key or a unique …

  [Read more...]
Magic deadlock: what locks are really set by InnoDB?
+0 Vote Up -0Vote Down

Megabytes of text had been written already on InnoDB locking and deadlocks. Still, even very simple cases of deadlocks while working with a table having only one row sometimes make people wonder what happened and why.

Today I want to check if this topic is explained well in the manual and existing blog posts and understood properly. So, it's an exercise for my dear readers and those who like to report bugs as much as I do.

Let's consider a very simple example. In session #1 with default transaction isolation level execute the following:
CREATE TABLE `tt` (
  `id` int(11) NOT NULL,
  …






  [Read more...]
MySQL 5.6.16 Overview and Highlights
+6 Vote Up -0Vote Down

MySQL 5.6.16 was recently released (it is the latest MySQL 5.6, is GA), and is available for download here:

http://dev.mysql.com/downloads/mysql/5.6.html

As opposed to the latest 5.5 release, this latest 5.6 release has quite a few more bug fixes, but that’s expected since 5.5 has been GA for much longer.

There were 2 minor functionality changes:

  • Previously, ALTER TABLE in MySQL 5.6 could alter a table such that the result had temporal columns in both 5.5 and 5.6 format. Now ALTER TABLE upgrades old temporal columns to 5.6 format for ADD COLUMN, CHANGE COLUMN, MODIFY COLUMN, …
  [Read more...]
10 Newer Entries Showing entries 31 to 40 of 196 10 Older Entries

Planet MySQL © 1995, 2015, Oracle Corporation and/or its affiliates   Legal Policies | Your Privacy Rights | Terms of Use

Content reproduced on this site is the property of the respective copyright holders. It is not reviewed in advance by Oracle and does not necessarily represent the opinion of Oracle or any other party.