by Zardosht.Kasheff | Jul 6, 2010 | MySQL
In my post from three weeks ago, I explained why the semantics of normal ad-hoc insertions with a primary key are expensive because they require disk seeks on large data sets. Towards the end of the post, I claimed that it would be better to use “replace into” or...
by Justin Swanhart | Jul 5, 2010 | Insight for Developers, MySQL
I very much like the fact that MySQL allows you to embed comments into SQL statements. These comments are extremely convenient, because they are written into MySQL log files as part of the query. This includes the general log, the binary log and the slow query log....
by Baron Schwartz | Jul 5, 2010 | Insight for DBAs, MySQL
When examining MySQL configuration, we quite often want to know how various buffer sizes are used. This matters because some buffers (sort_buffer_size for example) are allocated to their full size immediately as soon as they are needed, but others are effectively a...
by John.Partridge | Jul 3, 2010 | MySQL
Tokutek is pleased to announce immediate availability of TokuDB for MySQL, version 4.0. It is designed for continuous querying and analysis of large volumes of rapidly arriving and changing data, while maintaining full ACID properties. New in TokuDB v4.0 is our...
by Aleksandr Kuzminsky | Jul 1, 2010 | Insight for DBAs, MySQL
For a long time long types like BLOB, TEXT were not supported by Percona InnoDB Recovery Tool. The reason consists in a special way InnoDB stores BLOBs. An InnoDB table is stored in a clustered index called PRIMARY. It must exist even if a user hasn’t defined...
by Zardosht.Kasheff | Jun 30, 2010 | MySQL
In this post two weeks ago, I explained why the semantics of normal ad-hoc insertions with a primary key are expensive because they require disk seeks on large data sets. Towards the end of the post, I claimed that it would be better to use “replace into”...
by Peter Zaitsev | Jun 29, 2010 | Percona Software
Percona Server release 11.0 which we announced few days ago unfortunately was released with a bug introduced while implementing stripping comments in query cache which could cause server crash with certain types of queries if query cache is enabled. We have released...
by Yves Trudeau | Jun 29, 2010 | Insight for DBAs, MySQL
This post is the second of a series that started here. The first step to build the HA solution is to create two working instances, configure them to be EBS based and create a security group for them. A third instance, the client, will be discussed in part 7. Since...
by Zardosht.Kasheff | Jun 22, 2010 | MySQL
The analysis that shows how to make deletions really fast by using clustering keys and TokuDB’s fractal tree based engine also applies to make updates really fast. (I left it out of the last post to keep the story simple). As a quick example, let’s look at...
by Aleksandr Kuzminsky | Jun 21, 2010 | MySQL, Percona Software
Dear Community, Percona Server version 5.1.47-rel11.0 is available for download now. The changes in this release include: New features Percona Server is now based on MySQL 5.1.47, and XtraDB is now based on InnoDB plugin 1.0.8. XtraDB now uses the fast recovery code...
by Zardosht.Kasheff | Jun 18, 2010 | MySQL
Continuing in the theme from previous posts, I’d like to examine another case where we can eliminate all disk seeks from a MySQL operation and therefore get two orders-of-magnitude speedup. The general outline of these posts is: B-trees do insertion disk seeks....
by Yves Trudeau | Jun 17, 2010 | Insight for DBAs, MySQL
Like many, I have been seduced by the power and flexibility of Amazon EC2. Being able to launch new instances at will depending on the load, is almost too good to be true. Amazon has also some drawbacks, availability is not guaranteed and discovery protocols relying...
by Baron Schwartz | Jun 15, 2010 | Insight for Developers, MySQL
MySQL’s SHOW STATUS command has two counters that are often confusing and result in “what does that mean?” questions: Handler_read_rnd Handler_read_rnd_next As I understand it, there is some historical context to the choice of names here, hearkening...
by Justin Swanhart | Jun 15, 2010 | Insight for Developers, MySQL
While many people are familiar with the MySQL EXPLAIN command, fewer people are familiar with “explain extended” which was added in MySQL 4.1 EXPLAIN EXTENDED …can show you what the MySQL optimizer does to your query. You might not know this, but...
by Vadim Tkachenko | Jun 15, 2010 | Benchmarks, MySQL
(Note: The review was done as part of our consulting practice, but is totally independent and fully reflects our opinion) In my talk on MySQL Conference and Expo 2010 “An Overview of Flash Storage for Databases” I mentioned that most likely there are other...
by Peter Zaitsev | Jun 10, 2010 | Insight for DBAs, MySQL
I just wrote a large post on reasons for innodb main tablespace excessive growth and I thought it would make sense to explain briefly of why it is so frequently you have purge not being the problem at all and when out of no where you can see purge thread being unable...
by Peter Zaitsev | Jun 10, 2010 | Insight for DBAs, MySQL
So you’re running MySQL With innodb_file_per_table option but your ibdata1 file which holds main (or system) tablespace have grown dramatically from its starting 10MB size. What could be the reason of this growth and what you can do about it ? There are few...
by Peter Zaitsev | Jun 8, 2010 | Insight for DBAs, MySQL
Quite frequently I see people confused what table locks reported by SHOW INNODB STATUS really mean. Check this out for example: ---TRANSACTION 0 4872, ACTIVE 32 sec, process no 7142, OS thread id 1141287232 2 lock struct(s), heap size 368 MySQL thread id 8, query id...
by Zardosht.Kasheff | Jun 8, 2010 | MySQL
In my last post, I discussed how fractal tree data structures can be up to two orders of magnitude faster on deletions over B-trees. I focused on the deletions where the row entry is known (the storage engine API handler::delete_row), but I did not fully analyze how...
by Peter Zaitsev | Jun 7, 2010 | Benchmarks, Insight for Developers, MySQL
You might be familiar with Six Sigma business management strategy which is employed by variety of the companies in relationship to managing quality of its product. Six Sigma applies to number of defects – when you have reached six sigma quality in your...
