Drizzle FRM replacement: the table proto

Drizzle originally inherited the FRM file from MySQL (which inherited it from UNIREG). The FRM file stores metadata about a table; what columns it has, what type those columns are, what indexes, any default values, comments etc are all stored … Continue reading

The FRM file format

It’s fortunate that I’m watching Veronica Mars again with a mate; a more-than-you-think amount of detective work is required to understand the relationship (and format) of the TABLE_SHARE, the FRM file and HA_CREATE_INFO. Oh, also you’ll need drizzled/base.h and drizzled/structs.h … Continue reading

Some current MySQL Architecture writings

So, I’ve been looking around for a while (and a few times now) for any good resources that cover a bunch of MySQL architecture and technical details aimed towards the technically proficient but not MySQL literate audience. I haven’t really … Continue reading

Past, Present and future of MySQL and variants Part 1: Ghosts of MySQL Past

You can watch the video of my linux.conf.au 2014 talk here: http://mirror.linux.org.au/linux.conf.au/2014/Wednesday/28-Past_Present_and_future_of_MySQL_and_variants_-_Stewart_Smith.mp4 But let’s talk about things in blog form rather than video form :) Back in 1979, there was UNIREG. A text UI to records (rows) in a database … Continue reading

Some storage engine features you only get if you’re InnoDB

I had reason to look into the extended secondary index code in MariaDB and MySQL recently, and there was one bit that I really didn’t like. MariaDB: share->set_use_ext_keys_flag(legacy_db_type == DB_TYPE_INNODB); MySQL: use_extended_sk= (legacy_db_type == DB_TYPE_INNODB); In case you were wondering … Continue reading

The MySQL Cluster storage engine

This is one close to my heart. I’ve recently written on other storage engines: Where are they now: MySQL Storage Engines, The MERGE storage engine: not dead, just resting…. or forgotten and The MEMORY storage engine. Today, it’s the turn of MySQL Cluster. … Continue reading

Fun with Coverity found bugs (Episode 1)

Taking the inspiration of Valeriy Kravchuk great series of blog posts “Fun with Bugs” (and not http://funwithbugs.com/ which is about both caring for and eating bugs), and since I recently went and run Coverity against Drizzle, I thought I’d have a small series of … Continue reading

Writing A Storage Engine for Drizzle, Part 2: CREATE TABLE

The DDL code paths for Drizzle are increasingly different from MySQL. For example, the embedded_innodb StorageEngine CREATE TABLE code path is completely different than what it would have to be for MySQL. This is because of a number of reasons, … Continue reading