Bug reports can be fun. They can also be terrible. Either way they can be entertaining. On the Drizzle IRC channel today I saw a couple references to MySQL bug reports: it is stop working and Does not make toast (which reminds me of the Mozilla bug report about the kitchen sink). Got any other favourites1?
1 This one’s for Jay.
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Inspired by some recent posts about scripts for parsing mysqldump files, I thought I’d put my own little dump program out there for those looking for alternatives to mysqldump. It’s written in perl and only actually uses the mysqldump utility to dump the data portion of its file dumps. The rest is done via mysql’s internal show commands. Each database is dumped to it’s own directory, where each component in that database is dumped into five subdirs: schemas, routines, views, triggers & data. Inside these subdirs is a file per table and file per proc, etc. The data section is slightly different: as I mentioned it uses mysqldump to dump bulk insert statements into a sql file, one per table. So at any time, any or all components (including data) can be reloaded with a simple redirect or pipe back to mysql client: …
[Read more]In my business (weather) we use lots map based (Geo) information. Almost every table has latitude and longitude. Working with this kind of data can be exciting and frustrating. This should give you a quick start into GIS with MySQL.
“A geographic information system (GIS), or geographical information system, is any system that captures, stores, analyzes, manages, and presents data that are linked to location. In the simplest terms, GIS is the merging of cartography, statistical analysis, and database technology. GIS systems are used in cartography, remote sensing, land surveying, …
[Read more]I recently encountered an interesting case. A customer reported that mysqld crashed on start on OpenSUSE 11.2 kernel 2.6.31.12-0.2-desktop x86_64 with 96 GB RAM when the innodb_buffer_pool_size was set to anything more than 62 GB. I decided to try it with 76 GB. The error message was an assert due to a failed malloc() in ut_malloc_low() in ut/ut0mem.c inside InnoDB source code. InnoDB wraps the majority of its memory allocations in ut_malloc_low(), so to get an idea of the pattern of requested allocations I added a debugging fprintf() to tell me how much was being allocated and whether it was successful.
I discovered something interesting. I expected the allocation to fail on the 76 GB of the buffer pool, due to some weird memory mapping issue and a continuous block of 76 GB not being available. However, that is not what happened. 76 GB buffer was allocated successfully. What was failing is the allocation of 3.37GB after that. What in …
[Read more]The binary version for MySQL Cluster 7.1.5 has now been made available at http://www.mysql.com/downloads/cluster/
A description of all of the changes (fixes) that have gone into MySQL Cluster 7.1.5 (compared to 7.1.4) can be found in the MySQL Cluster 7.1.5 Change Log.
ODTUG invited me to give a webinar and I said yes, so this Thursday you’re invited to join me as I talk about MySQL performance. We’ve come a very long way towards a MySQL that can perform well on modern hardware, and there really isn’t broad recognition of this. A lot of the best work has gone into the InnoDB “plugin” storage engine, which was announced after my co-authors and I sent High Performance MySQL to the press. I will explain what you should be doing differently now than you did two years ago, and suggest a performance-in-a-nutshell configuration baseline for MySQL that’s quite different from what I’d have said in 2008. You can register for free through GoToWebinar. See you there.
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Lets paint the picture:
Scenario part 1 : Migrating a couple thousand stored procedures
from database technology X to mysql
Scenario part 2 : Legacy system where the people who wrote it
left a long time ago
Scenario part 3 : Developers sure can get real creative and
invent all kinds of ways to get data (eg: having a stored proc
which formulates a big query using concat after going through a
bunch of conditions (fair enough), BUT the parts making up the
different queries are stored in a table on a database rather than
within the stored proc itself) … talk about KIS – Keep it
simple!!
Scenario part 4 : This stored proc references 18 tables, 4 views,
and another two stored procedures on 5 databases
Now close your eyes and try to imagine that for a few seconds, nah kidding don’t want you to hurt yourself.
I wonder, who’s gonna cover my health insurance if i go crazy? :)
mysql 02:55:47 DEV …
[Read more]Collaborate 2011 is a database operational conference to be held in Orlando, Florida April 10th - 14th 2011. Unfortunately, the O'Reilly MySQL Conference has been scheduled for the same week; however, I am working with the conference committee to make sure that speakers that want to attend both are scheduled appropriately (I intend on going to both!). The call for presentations is now open through the end of September, so you have just over a month to submit your proposals. Experience has shown that the best presentations are submitted well in advance of the deadline -- I guess when folks are time-crunched by the deadline they do not make such great abstracts....Speakers whose presentations are accepted receive free admission to the conference and a speaker thank-you gift.
When running query against a database the following error can be generated:
ERROR 2006 (HY000) at line NNN: MySQL server has gone away
Where "NNN" is the line number of the script currently being run where the error occurred.
Possible Causes and Resolution
This is a general error which can have a number of possible causes. The one certainty is that the MySQL database is no longer listening on
ODTUG invited me to give a webinar and I said yes, so this Thursday you’re invited to join me as I talk about MySQL performance. We’ve come a very long way towards a MySQL that can perform well on modern hardware, and there really isn’t broad recognition of this. A lot of the best work has gone into the InnoDB “plugin” storage engine, which was announced after my co-authors and I sent High Performance MySQL to the press.
