Search Results for: where am i

How rows_sent can be more than rows_examined?

When looking at queries that are candidates for optimization I often recommend that people look at rows_sent and rows_examined values as available in the slow query log (as well as some other places). If rows_examined is by far larger than rows_sent, say 100 larger, then the query is a great candidate for optimization. Optimization could […]

Renaming database schema in MySQL

One of the routine tasks for a DBA is renaming database schemas, and as such MySQL added a command to carry out that purpose called “RENAME DATABASE <database_name>”. However this command just made it through a few minor releases before being discontinued (from MySQL 5.1.7 to 5.1.23). Here’s a link to the reference manual regarding […]

Percona team to attend Buenos Aires MySQL conference Oct. 15-16

This is to announce that me and Daniel Nichter (Lead of Percona Toolkit) are coming to the MYSQL NOSQL & CLOUD CONFERENCE & EXPO in Buenos Aires, Argentina on Oct. 15-16. There also will be local Percona experts in attendance. Talks from Percona include: Percona XtraDB Cluster – Basic installation and setup by Martín Arrieta […]

Running MySQL 5.6 on Amazon RDS: Webinar followup questions answered

Thanks to everyone who attended last week’s webinar, Running MySQL 5.6 on Amazon RDS.” If you weren’t able to attend, the recording and slides are available for viewing/download (or, if you were able to attend and just want to see it again). I’ve also answered the questions I didn’t have a chance to field during […]

Testing Intel, Samsung & SanDisk SATA SSD

While working on the service architecture for one of our projects, I considered several SATA SSD options as the possible main storage for the data. The system will be quite write intensive, so the main interest is the write performance on capacities close to full-size storage. After some research I picked several candidates (I show […]

Amazon RDS with MySQL 5.6 – Configuration Variables

One longstanding complaint I have heard for the past several years, and still hear today, is that Amazon’s Relational Database Service (RDS) does not allow the configuration flexibility as running MySQL in an ec2 instance. While true, this ignores the consistent work that Amazon has done to provide access to the most important configuration variables […]

Recovering temporal types in MySQL 5.6: TIME, TIMESTAMP and DATETIME

MySQL 5.6 introduces a new feature – microseconds resolution in some temporal types. As of 5.6.4 TIME, TIMESTAMP and DATETIME can have a fractional part. To create a field with subseconds you can specify precision in brackets: TIME(3), DATETIME(6) etc. Obviously, the new feature requires the format change. All three types may now have a […]

MySQL and the SSB – Part 2 – MyISAM vs InnoDB low concurrency

This blog post is part two in what is now a continuing series on the Star Schema Benchmark. In my previous blog post I compared MySQL 5.5.30 to MySQL 5.6.10, both with default settings using only the InnoDB storage engine.  In my testing I discovered that innodb_old_blocks_time had an effect on performance of the benchmark.  There was […]