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Displaying posts with tag: storage (reset)
Berkeley DB now supports SQL (again)

Berkeley DB (BDB) is undoubtedly the workhorse among the opensource embedded database engines. It started as a university project in the mid-eighties and was further developed by Sleepycat Software, until it got acquired by Oracle in February 2006.

I had the impression that BDB had lost a lot of its popularity among opensource developers to SQLite in recent times, which has evolved into becoming the default choice for developers looking for an embedded data store. I'd assume primarily because the code is not released under any particular license, but put in the public domain

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MySQL University: MySQL Column Databases

This Thursday (March 4th, 15:00 UTC - slightly later than usual), Robin Schumacher will present MySQL Column Databases. If you're doing Data Warehouse with your databases this is a must-attend, but it's also interesting to learn what typical other scenarios there are for using column-based storage engines, and how column databases work in the first place.

For MySQL University sessions, point your browser to this page. You need a browser with a working Flash plugin. You may register for a Dimdim account, but you don't have to. (Dimdim is the conferencing system we're using for MySQL University sessions. It provides integrated voice streaming, chat, whiteboard, session recording, …

[Read more]
MySQL University: MySQL Column Databases

This Thursday (March 4th, 15:00 UTC - slightly later than usual), Robin Schumacher will present MySQL Column Databases. If you're doing Data Warehouse with your databases this is a must-attend, but it's also interesting to learn what typical other scenarios there are for using column-based storage engines, and how column databases work in the first place.

For MySQL University sessions, point your browser to this page. You need a browser with a working Flash plugin. You may register for a Dimdim account, but you don't have to. (Dimdim is the conferencing system we're using for MySQL University sessions. It provides integrated voice streaming, chat, whiteboard, session recording, …

[Read more]
MySQL University: MySQL Column Databases

This Thursday (March 4th, 15:00 UTC - slightly later than usual), Robin Schumacher will present MySQL Column Databases. If you're doing Data Warehouse with your databases this is a must-attend, but it's also interesting to learn what typical other scenarios there are for using column-based storage engines, and how column databases work in the first place.

For MySQL University sessions, point your browser to this page. You need a browser with a working Flash plugin. You may register for a Dimdim account, but you don't have to. (Dimdim is the conferencing system we're using for MySQL University sessions. It provides integrated voice streaming, chat, whiteboard, session recording, …

[Read more]
CAOS Theory Podcast 2010.02.05

Topics for this podcast:

*Matt Asay moves from Alfresco to Canonical
*GPL fade fuels heated discussion
*Apple’s iPad and its enterprise and open source impact
*Open source in data warehousing and storage
*Our perspective on Oracle’s plans for Sun open source

iTunes or direct download (32:50, 9.2 MB)

Notes on HEAP/MyISAM Index Key Handling on WRITE

Disclaimer: This post is based on HEAP/MyISAM’s sourcecode in Drizzle.

Here are my brief notes on investigating how index keys are generated in HEAP and MyISAM. I lurked through these because I’ve started preparing for decent index support in BlitzDB. I also wrote this to assist my biological memory for later grepping (I have terrible memory for names). I’m only going to cover key generation on write in this post. Otherwise this post is going to be massive.

HEAP Engine

The index structure of HEAP can be either BTREE or HASH (in MySQL doc terms). Like other engines HEAP has a structure for keeping Key definition (parts, type, logic and etc). This structure is called HP_KEYDEF and it contains function pointers for write, delete, and getting the length of the key. These function pointers are assigned to at table creation or when the table is opened. The assigned function depends on the data structure …

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TEXT vs. VARCHAR

On first glance, it looks like TEXT and VARCHAR can store the same information. However, there are fundamental differences between the way TEXT fields and VARCHAR fields work, which are important to take into consideration.

Standard
VARCHAR is actually part of the ISO SQL:2003 standard; The TEXT data types, including TINYTEXT, are non-standard.

Storage
TEXT data types are stored as separate objects from the tables and result sets that contain them. This storage is transparent — there is no difference in how a query involving a TEXT field is written versus one involving a VARCHAR field. Since TEXT is not stored as part of a row, retrieval of TEXT fields requires extra [edited 1/22] memory overhead.


Maximum VARCHAR length
The maximum row length of a VARCHAR is restricted by the maximum row length of a table. This is 65,535 bytes …

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MySQL University: The Spider Storage Engine

This Thursday (November 26th, 14:00 UTC), Giuseppe Maxia will present the Spider Storage Engine. This session was originally scheduled for October 15th but had to be postponed for technical reasons.

Here's from the abstract: Everybody needs sharding. Which is not easy to maintain. Being tied to the application layer, sharding is hard to export and to interact with. The Spider storage engine, a plugin for MySQL 5.1 and later, solves the problem in a transparent way. It is an extension of partitioning. Using this engine, the user can deal transparently with multiple backends in the server layer. This means that the data is accessible from any application without code changes. This lecture …

[Read more]
MySQL University: The Spider Storage Engine

This Thursday (November 26th, 14:00 UTC), Giuseppe Maxia will present the Spider Storage Engine. This session was originally scheduled for October 15th but had to be postponed for technical reasons.

Here's from the abstract: Everybody needs sharding. Which is not easy to maintain. Being tied to the application layer, sharding is hard to export and to interact with. The Spider storage engine, a plugin for MySQL 5.1 and later, solves the problem in a transparent way. It is an extension of partitioning. Using this engine, the user can deal transparently with multiple backends in the server layer. This means that the data is accessible from any application without code changes. This lecture …

[Read more]
MySQL University: The Spider Storage Engine

This Thursday (November 26th, 14:00 UTC), Giuseppe Maxia will present the Spider Storage Engine. This session was originally scheduled for October 15th but had to be postponed for technical reasons.

Here's from the abstract: Everybody needs sharding. Which is not easy to maintain. Being tied to the application layer, sharding is hard to export and to interact with. The Spider storage engine, a plugin for MySQL 5.1 and later, solves the problem in a transparent way. It is an extension of partitioning. Using this engine, the user can deal transparently with multiple backends in the server layer. This means that the data is accessible from any application without code changes. This …

[Read more]
Showing entries 31 to 40 of 80
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