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Search Results for: date range index

MySQL Indexing Best Practices: Webinar Questions Followup

I had a lot of questions on my MySQL Indexing: Best Practices Webinar (both recording and slides are available now) We had lots of questions. I did not have time to answer some and others …


Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5

This is the second blog post in the series of blog posts leading up to the talk comparing the optimizer enhancements in MySQL 5.6 and MariaDB 5.5. This blog post is aimed at the optimizer …


Partitioning, Free Lunches, & Indexing, Part 2

Review In part one, I presented a very brief and particular view of partitioning. I covered what partitioning is, with hardly a mention of why one would use partitioning. In this post, I’ll talk about …


Partitioning, Free Lunches, and Indexing

Why partition? Partitioning is a commonly touted method for achieving performance in MySQL and other databases. (See here, here, here and many other examples.) I started wondering where the performance from partitions comes from, and …


Joining on range? Wrong!

The problem I am going to describe is likely to be around since the very beginning of MySQL, however unless you carefully analyse and profile your queries, it might easily go unnoticed. I used it …


How (not) to find unused indexes

I’ve seen a few people link to an INFORMATION_SCHEMA query to be able to find any indexes that have low cardinality, in an effort to find out what indexes should be removed.  This method is …


Multi Column indexes vs Index Merge

The mistake I commonly see among MySQL users is how indexes are created. Quite commonly people just index individual columns as they are referenced in where clause thinking this is the optimal indexing strategy. For …


How clustering indexes sometimes help UPDATE and DELETE performance

I recently posted a blog entry on clustering indexes, which are good for speeding up queries. Eric Day brought up the concern that clustering indexes might degrade update performance. This is often true, since any …


Introducing Multiple Clustering Indexes

In this posting I’ll describe TokuDB’s multiple clustering index feature. In general (not just for TokuDB) a clustered index or a clustering index is an index that stores the all of the data for the …


Multiple column index vs multiple indexes

(There is an updated version of the content in this post by Percona’s Stephane Combaudon available here.) After my previous post there were questions raised about Index Merge on Multiple Indexes vs Two Column Index …