Search Results for: what could i use an access query for

MySQL: Followup on UNION for query optimization, Query profiling

Few days ago I wrote an article about using UNION to implement loose index scan. First I should mention double IN also works same way so you do not have to use the union. So changing query to:

So as you see there are really different types of ranges in MySQL. IN range allows […]

Why MySQL could be slow with large tables ?

If you’ve been reading enough database related forums, mailing lists or blogs you probably heard complains about MySQL being unable to handle more than 1.000.000 (or select any other number) rows by some of the users. On other hand it is well known with customers like Google, Yahoo, LiveJournal,Technocarati MySQL has installations with many billions […]

MySQL 5.6 Transportable Tablespaces best practices

In MySQL 5.6 Oracle introduced a Transportable Tablespace feature (copying tablespaces to another server) and Percona Server adopted it for partial backups which means you can now take individual database or table backups and your destination server can be a vanilla MySQL server. Moreover, since Percona Server 5.6, innodb_import_table_from_xtrabackup is obsolete as Percona Server also […]

Tips from the trenches for over-extended MySQL DBAs

This post is a follow-up to my November 19 webinar, “Tips from the Trenches: A Guide to Preventing Downtime for the Over-Extended DBA,” during which I described some of the most common reasons DBAs experience avoidable downtime. The session was aimed at the “over-stretched DBA,” identified as the MySQL DBA short of time or an […]

Q&A: Percona XtraDB Cluster as a MySQL HA solution for OpenStack

Thanks to all who attended my Nov. 12 webinar titled, “Percona XtraDB Cluster as a MySQL HA Solution for OpenStack.” I had several questions which I covered at the end and a few that I didn’t. You can view the entire webinar and download the slides here. Q: Is the read,write speed reduced in Galera […]

How to deal with MySQL deadlocks

A deadlock in MySQL happens when two or more transactions mutually hold and request for locks, creating a cycle of dependencies. In a transaction system, deadlocks are a fact of life and not completely avoidable. InnoDB automatically detects transaction deadlocks, rollbacks a transaction immediately and returns an error. It uses a metric to pick the […]

Innodb transaction history often hides dangerous ‘debt’

In many write-intensive workloads Innodb/XtraDB storage engines you may see hidden and dangerous “debt” being accumulated – unpurged transaction “history” which if not kept in check over time will cause serve performance regression or will take all free space and cause an outage. Let’s talk about where it comes from and what can you do […]

MySQL upgrade best practices

MySQL upgrades are necessary tasks and we field a variety of questions here at Percona Support regarding MySQL upgrade best practices. This post highlights recommended ways to upgrade MySQL in different scenarios. Why are MySQL upgrades needed? The reasons are many and include: Access to new features, performance benefits, bug fixes…. However, MySQL upgrades can […]

Getting to know TokuDB for MySQL

During last April’s Percona Live MySQL Conference and Expo, TokuDB celebrated it’s first full-year as an open source storage engine. I still remember reading the official announcement and the expectations it created one year ago. The premises were very interesting as it had the potential of helping MySQL manage “big data” in a way InnoDB just […]