Ronald Bradford last week posted about memcached not being multi-threaded on Ubuntu, something he discovered via some small utilities that are bundled with libmemcached, written by Brian Aker.

When I noticed there were no Ubuntu packages for libmemcached (or the CLI tools) I decided to create some.

For your enjoyment: http://ubuntu.cafuego.net/dists/jaunty-cafuego/memcached/ (Source debs are included)

The repository also contains a memcached that has been re-compiled with multithreading enabled.

If you use innodb_file_per_table = 1 and innodb_open_files = X (whatever amount is suitable for your server) there’s no way internal to MySQL for finding out how many IBD files InnoDB actually has open. Neither SHOW GLOBAL STATUS LIKE ‘innodb%’ nor SHOW ENGINE INNODB STATUS provide this information.

Many sites do have a growing number of tables, so you’ll want to know when it’s time to up the number (and potentially also open-files-limit). Solution: sudo lsof | grep -c “\.ibd$”

Followup on Experiment: MySQL tmpdir on tmpfs, about tmpdir=/dev/shm in my.cnf (it’s not a dynamic variable that can be set at runtime). It’s working well, also confirmed by comments from others that they’ve been using it for a while.

This particular setting is Linux specific. On Solaris, the default /tmp is already on a tmpfs so that’s fine too. Brian reminded me that this tweak is also useful if you’re stuck with a 32-bit OS as you can then utilise some more memory in a practical way.

Extra useful hint from Harrison: if you are using replication, you will also want slave_load_tmpdir=/tmp on your slave (real disk which survives a restart). The issue is that with statement based binary logging, there are many events which create a file for a replicated LOAD DATA INFILE. If …

Executive Summary: A query like TPC-H Query 17 can be sped up by large factors by using straight_joins and clustering indexes.  (This entry posted by Dave.)

In a previous post, we wrote about queries like TPC-H query 2, and the use of straight_join to improve performance. 
This week, we consider Query 17, described by the TPC-H documentation as

“The Small-Quantity-Order Revenue Query considers parts of a given brand and with a given container type and determines the average lineitem quantity of such parts ordered for all orders (past and pending) in the 7-year database.  What would the average yearly gross (undiscounted) loss in revenue if orders for these parts with a quantity of this average were no longer taken?”

Our initial run on Q17 (same hardware as before) timed out …

So I got my hands on an HP mini 1000 last week. Not bad for $250 at Best Buy, although it has needed some help, namely:

- External USB hard drive - I got the Mini 1000 that comes with a 16 Gb SSD, and want this to be my primary computer (I'm not a gamer, just web surfing and *occasional* video editing). I bought a 320Gb Buffalo Mini Station, for about $60 at Microcenter.

- 2 Gb RAM - already had a stick, free for me (otherwise $20), easy to pop in.

- USB to VGA adapter - HP has a nice proprietary VGA port, to which they didn't have an adapter for a long time (6 months or so)....now, the adapters exist, but they're out of stock. I bought a USB to VGA adaptor at Microcenter for about $70.

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There appears to be much ado about Google Fusion Tables (GFT) threatening the database stalwarts like Oracle and IBM. Am I missing something? It appears to be less like a database and more like Google Docs’ Spreadsheet. The difference being that GFT replaces formulaic functions with bulk capabilities like filtering, aggregation and merging.

GFT appears to have no query capability, other than the ability to filter data. In other words, you can narrow the data down to what fits your criteria and then you can visualize that data. Instead of the formulaic "processing" you get from a database, you have the ability to aggregate data (combine disparate data), filter it (show stuff that fits your criteria) and then visualize it so that individuals can discern correlations and trends.

If you’re having trouble installing MySQL 5.1 on a Windows server, I’d recommend the following process.  Don’t skip the first steps that describe the uninstall and removal of the previous install as this seems to clear up most issues.   For the uninstall, I’d recommend manually deleting data files.  Caution: deleting the data files will delete any data previously entered into MySQL.

1.  Remove previous MySQL installs (and remnants)

a.  Stop the MySQL service ( Start | Control Panel | Administrative Tools | Services)

b.  Remove MySQL using Windows Add or Remove Programs (Start | Control Panel | Add or Remove Programs)

c.  Clean up (delete) the data directory  (assuming that you don’t have data that you need) c:\documents and settings\all users\application data\mysql
 

d.  Clean up (delete) any remaining …

There appears to be much ado about Google Fusion Tables (GFT) threatening the database stalwarts like Oracle and IBM. Am I missing something? It appears to be less like a database and more like Google Docs’ Spreadsheet. The difference being that GFT replaces formulaic functions with bulk capabilities like filtering, aggregation and merging.

GFT appears to have no query capability, other than the ability to filter data. In other words, you can narrow the data down to what fits your criteria and then you can visualize that data. Instead of the formulaic "processing" you get from a database, you have the ability to aggregate data (combine disparate data), filter it (show stuff that fits your criteria) and then visualize it so that individuals can discern correlations and trends.

Hi all,

Several weeks ago, Eric Day added support for Drizzle into the main part of Sphinx, the indexer. I was testing and noticed the the "search" utility, which searches an index directly and can have a query that fetches whatever is needed from the database using the document IDs from the search,

sql_query_info

and found that no results came from the database. That's because "search" only has MySQL support, whereas the main Sphinx code base has support for a number of databases, and uses inheritance to easily support them all so that whatever database you use, it automatically uses the correct connection. So, I added drizzle support to "search". The one issue is that unlike the indexer, "search" can only support one database as a time. So, if you want to compile in Drizzle support, you have to disable MySQL support for "search" to work correctly:

./configure --with-drizzle --without-mysql
…

After hearing rumblings that a new release model was coming and then announcements that a new model was coming, I took the time  to watch the MySQL University session on it Thursday. I have thought for a long time that previous method of release management was less than perfect for MySQL Server resulting in long time periods between “GA” releases.

After listening to the session I have a great deal of hope that this will be a very positive change. I would recommend that you go listen to the session when it is posted (the pdf of slides are available but not the dim dim recording yet). It is very thorough. The basics are that server development is being moved to what is called a “Milestone Release Model”. These milestone releases will occur every three …