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The Effects of Database Heap Storage Choices in MongoDB

William Zola over at MongoDB gave a great talk called “The (Only) Three Reasons for Slow MongoDB Performance”. It reminded me of an interesting characteristic of updates in MongoDB. Because MongoDB’s main data store is …

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On SSDs – Lifespans, Health Measurement and RAID

Solid State Drive (SSD) have made it big and have made their way not only in desktop computing but also in mission-critical servers. SSDs have proved to be a break-through in IO performance and leave …

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A case for MariaDB’s Hash Joins

MariaDB 5.3/5.5 has introduced a new join type “Hash Joins” which is an implementation of a Classic Block-based Hash Join Algorithm. In this post we will see what the Hash Join is, how it works …

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How InnoDB handles REDO logging

Xaprb (Baron) recently blogged about how InnoDB performs a checkpoint , I thought it might be useful to explain another important mechanism that affects both response time and throughput – The transaction log.

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Ultimate MySQL variable and status reference list

I am constantly referring to the amazing MySQL manual, especially the option and variable reference table. But just as frequently, I want to look up blog posts on variables, or look for content in the …

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Is your server’s performance about to degrade?

I’ve been talking and writing a bit lately about the scaling problems I’m seeing on fast servers running lots of queries. As a rough guide, I’m seeing this in servers running 20k queries per second …

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When the subselect runs faster

A few weeks ago, we had a query optimization request from one of our customer. The query was very simple like:

This column in the table is looks like this:

The table have …

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Four ways to optimize paginated displays

A paginated display is one of the top optimization scenarios we see in the real world. Search results pages, leaderboards, and most-popular lists are good examples. You know the design pattern: display 20 results in …

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10+ Ways to Crash or Overload MySQL

People are sometimes contacting me and asking about bugs like this which provide a trivial way to crash MySQL to the user with basic privileges and asking me what to do. My answer to them …

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Should MySQL Extend GROUP BY Syntax ?

Jan has a good article about finding the row matching some value in the group: This is one illustration of group by limitations in SQL language which is not offset by any MySQL specific extensions,yet …

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