Home |  MySQL Buzz |  FAQ |  Feeds |  Submit your blog feed |  Feedback |  Archive |  Aggregate feed RSS 2.0 English Deutsch Español Français Italiano 日本語 Русский Português 中文
Showing entries 1 to 5

Displaying posts with tag: cursor (reset)

Using a mysql cursor in a stored procedure
+0 Vote Up -0Vote Down

Example using a mysql cursor in a stored procedure. Mysql Cursor example DELIMITER $$   DROP PROCEDURE IF EXISTS mysql_cursor_example $$ CREATE PROCEDURE mysql_cursor_example ( IN in_name VARCHAR(255) ) BEGIN -- First we declare all the variables we will need DECLARE l_name VARCHAR(255); -- flag which will be set to true, when cursor reaches end [...]
A more complete look at Storage Engine API
+3 Vote Up -0Vote Down

Okay… So I’ve blogged many times before about the Storage Engine API in Drizzle. This API is somewhat inherited from MySQL. We have very much attempted to make it a much cleaner interface. Our goals in making changes include: make it much easier to write and maintain a storage engine, make the upper layer code obviously correct and clear in what it’s doing and being able to more easily introduce optimisations.

I’ve recently added a Storage Engine that is only used in testing: storage_engine_api_tester. I’ve blogged on it producing call graphs (really state transition graphs) before both for Storage Engine and Cursor.

I’ve been expanding the test. My

  [Read more...]
Cursor states
+2 Vote Up -0Vote Down

Following on from my post yesterday on the various states of a Storage Engine, I said I’d have a go with the Cursor object too. A Cursor is used by the Drizzle kernel to get and set data in a table. There can be more than one cursor open at once, and more than one per thread. If your engine cannot cope with this, it is its responsibility to figure it out and return the appropriate errors.

Let’s look at a really simple operation, inserting a couple of rows and then reading them back via a full table scan.

Now, this graph is slightly incomplete as there is no doEndTableScan() call. But you can see

  [Read more...]
Storage Engine API state graph
+2 Vote Up -0Vote Down

Drizzle still has a number of quirks inherited from the MySQL Storage Engine API (e.g. BLOBs, row buffer, CREATE SELECT and lack of DDL transaction boundaries, key tuple format). One of the things we fixed a long time ago was to have proper methods for StorageEngines to be called for: startTransaction, startStatement, endStatement, commit and rollback.

If you’ve had to implement a transactional storage engine in MySQL you will be well aware of the pattern

  [Read more...]
A Faster MySQL Database Size Google Chart
+0 Vote Up -0Vote Down
Abstract - As described by Walter Heck, MySQL database size can be visualized using Google Charts. With a minor code improvement the URL for the chart can be obtained twice as fast. With some more modification, the number of lines can be cut down resulting in a function that is half as long.

Hi!

It's been a while since I posted - I admit I'm struggling for a bit to balance time and attention to the day job, writing a book, preparing my talks for the MySQL user's conference and of

  [Read more...]
Showing entries 1 to 5

Planet MySQL © 1995, 2014, Oracle Corporation and/or its affiliates   Legal Policies | Your Privacy Rights | Terms of Use

Content reproduced on this site is the property of the respective copyright holders. It is not reviewed in advance by Oracle and does not necessarily represent the opinion of Oracle or any other party.