Since I recently wrote about both MySQL error 1071 and error 1070 I decided to continue the pattern with a quick note on MySQL error 1069. In case you've never seen it before, this is MySQL error 1069:

ERROR 1069 (42000): Too many keys specified; max 64 keys allowed

I can't think of a valid use case that requires more than 64 indexes on a MySQL table, but it's possible to get this error by inadvertantly adding lots of duplicate indexes to a table. This can happen if you don't explicitly name your indexes.

Read on for examples...

If I try to add the same named …

Different applications may require different level of availability.   This blog is written to provide only the details on Distributed Replicated Block Device (DRBD) with MySQL running in Active-Passive Clustering to allow failover between 2 nodes. 

In many OS clustering technology, Shared Storage is required to allow data to be readable between the clustered nodes.

 
MySQL HA with DRBD is a leading solution to offer

• - An end-to-end, integrated stack of mature and proven open source technologies, fully supported by Oracle;
• Automatic failover and recovery for service continuity;
• Mirroring, via synchronous replication, to ensure failover between nodes without the risk of losing committed transactions;
• Building of HA clusters from commodity hardware, without the requirement for shared-storage.

 

To …

This is the next part of the stories about MySQL 5.7 Performance..

So far, the previous story was about reaching 645K QPS with SQL queries, while in reality it's only a half of the full story ;-) -- because when last year we've reached 500K QPS due a huge improvement on the TRX-list code, the same improvement made a negative impact on the all single-table test workloads..

What happened finally :

• the new code changes dramatically lowered contention on TRX-list (trx_sys mutex)
• which is made MDL related locking much more hot..
• and if one table becomes hot on a workload, MDL lock contention then is hitting its highest level..

So far, it was clear that MDL is needed a fix. Specially seeing that on 8-tables workload we're …

As I mentioned on my last post, where I compared the default configurations options in 5.6 and 5.7, I have been doing some testing for a particular load in several versions of MySQL. What I have been checking is different ways to load a CSV file (the same file I used for testing the compression tools) into MySQL. For those seasoned MySQL DBAs and programmers, you probably know the answer, so you can jump over to my 5.6 versus 5.7 results. However, the first part of this post is dedicated for developers and MySQL beginners that want to know the answer to the title question, in a step-by-step fashion. I must say I also learned something, as I under- and over-estimated some of the effects of certain …

Good news for those wanting to run MariaDB on POWER systems, the latest 10.0 bzr tree (as of a couple of weeks ago) builds and runs well!

I recently pulled the latest MariaDB 10.0 from BZR and built it on a POWER8 system in the lab to run some quick tests. The MariaDB team has done some work on getting MariaDB to run on POWER recently, a bunch of which is based off my work on MySQL on POWER.

There’s obviously still some work in progress going on, but my initial results show performance within around 10% of MySQL, so with a bit of work we will hopefully see MariaDB reach performance parity.

One interesting find was the code to account for thread memory usage uses a single atomic variable: this does not scale and does end up showing up on profiles.

I’ll comment more on the code in a future post, but it looks like we will have MariaDB being functional on POWER in an upcoming release.

MySQL replication is a core process for maintaining multiple copies of data – and replication is a very important aspect in database administration. In order to synchronize data between master and slaves you need to make sure that data transfers smoothly, and to do so you need to act promptly regarding replication errors to continue data synchronization. Here on the Percona Support team, we often help customers with replication broken-related issues. In this post I’ll highlight the top most critical replication error code 1236 along with the causes and cure. MySQL replication error “Got fatal error 1236” can be triggered by multiple reasons and I will try to cover all of them.

…

MariaDB 10.0.14 was recently released, and is available for download here:

https://downloads.mariadb.org/mariadb/10.0.14/

This is the fifth GA release of MariaDB 10.0, and 15th overall release of MariaDB 10.0.

This is primarily a bug-fix release. (MariaDB 10.0 is the current stable series of MariaDB. It is an evolution of the MariaDB 5.5 with several entirely new features not found anywhere else and with backported and reimplemented features from MySQL 5.6.)

Here are the main items of note:

1. TokuDB upgraded to 7.5.0
2. XtraDB upgraded to 5.6.20-68.0
3. InnoDB upgraded to 5.6.20
4. …

MySQL 5.7.5 was recently released (it is the latest MySQL 5.7, and is the “m15″ or “Milestone 15″ release), and is available for download here and here.

As for the fixes/changes, there are quite a few (the official release was split into 3 separate emails), which is expected in such an early milestone release.

The main highlights for me were (though the enhancements, and potentially impactful changes, are definitely not limited to this list):

• InnoDB: The innodb_buffer_pool_size parameter is now dynamic, allowing you to resize the buffer pool without restarting the server. The resizing operation, which involves moving pages to a new location in memory, is performed chunks. Chunk size is configurable using the new …

It was great to see the recent announcement of MySQL 5.7.5 over at the MySQL Server Team blog. I’m looking forward to throwing this release at some of the POWER8 systems we have for a couple of really good reasons: 1) Does it work better than previous MySQL 5.7 releases “out of the box” on POWER? 2) What do the scalability improvements in 5.7.5 mean for peak QPS on POWER (and can I set a new record?).

Looking through the list of changes, I’m (casually not) surprised as to the number of features and the amount of work that echoes what we were working on in Drizzle a few years ago.

A closer look at the source for 5.7.5 may also prove enlightening, I wonder how the MySQL team is coping with a lot of the code rot legacy and the absolutely atrocious internal APIs they …

Direct Schema Tree Action Buttons

The schema tree in the SQL Editor now has some very convenient buttons for accessing the most used functions for each object type:

• Table or Schema Inspector
• Object structure editor
• Table data browser/editor
• Call Stored Procedure or Function

Format Note Objects in Diagrams

Note objects in diagrams can now be resized and have its contents automatically rearranged. You can also change style attributes like font, background color and text color.

Other improvements and bug fixes that make a difference

MySQL password is remembered for the session, even if not …