Netapp, enterprise network attached storage devices with OS, Data ONTAP has a per volume specific variable called 'maxfiles'. Basically the maximum number of inodes the volume can consume independent of disk utilization.

Unfortunately this variable must be set per volume, it cannot be 'unlimited' and it cannot be downsized.

According to the man page:

DESCRIPTION
maxfiles increases the number of files that a volume can
hold, as close as possible to max. File inodes are stored
in blocks, and the filer may round the requested max num-
ber of files to the nearest block.

Once increased, the value of max can never be lowered, so
the new value must be larger than the current value.



Further increasing this value to be an unlimited-like variable consumes filer RAM and will result in less usable filer RAM after a Data ONTAP OS …

I am very fortunate to be sent to a Percona innodb low level conference - with one of the guys who has written the High Performance MySQL book. One of the key items will be to dive deep into the Innodb kernel and find out what the hell the thing is doing. To that end I'm going post what I know about the 'show innodb status' output - now my aim from this conference is to pick up on some of the areas that I'm green in to identify and resolve more MySQL performance problems.

So here is my 'show innodb status' walkthrough:

mysql> show innodb status\G*************************** 1. row *************************** Type: InnoDB Name:Status:=====================================100308 17:05:14 INNODB MONITOR OUTPUT=====================================Per second averages calculated from the last 14 secondsThe following information is based on stats gathered in the last 14 seconds - Generally a good 30 seconds should pass …

I work for a start-up and like the folks at virtually every start-up we dream of being covered by one of the Big 8  business publications: The Wall Street Journal, The New York Times, Forbes, Fortune, BusinessWeek, The Economist, the Financial Times, and USA Today.

The folks at ITDatabase took a closer look at how they cover the tech industry and surveyed a group of veterans from major tech PR agencies to see what their experiences were like. The …

In MySQL5 MySQL implemented changes so you can view global status (counters) and session counters. In 5.1 MySQL extended this and implemented this information in the INFORMATION_SCHEMA.GLOBAL_STATUS and INFORMATION_STATUS.SESSION_STATUS tables.

Global status

mysql> SELECT * FROM GLOBAL_STATUS WHERE VARIABLE_NAME = 'COM_SELECT'\G*************************** 1. row *************************** VARIABLE_NAME: COM_SELECTVARIABLE_VALUE: 2076641 row in set (0.02 sec)

mysql> SHOW GLOBAL STATUS LIKE 'Com_select';+---------------+--------+| Variable_name | Value |+---------------+--------+| Com_select | 207664 | +---------------+--------+1 row in set (0.03 sec)
Session status
mysql> SHOW SESSION STATUS LIKE 'Com_select';+---------------+-------+| Variable_name | Value |+---------------+-------+| Com_select | 13 | +---------------+-------+1 row in set (0.02 sec)

mysql> …

I’m seeking help from the MySQL community for what tools are used today to generate complex reports for enterprise applications that use MySQL. In an Oracle world, you have Oracle Report Writer, in Microsoft Crystal Reports.

In the open source world there is Jasper Reports, Pentaho Reports and BIRT however I don’t know the power of complex reporting with these.

If anybody has experience using or evaluating these tools please let me know. This may lead to possible work.

I was privileged to lead a MySQL University session last week on MySQL-based column databases - what they are, how they work, why you should use them, cases where you shouldn't use them, benchmarks showing their performance, and more. I covered the main MySQL column databases - Infobright, Kickfire, and InfiniDB - and discussed the various features, benRead More...

I'm pleased to announce the release of Spider storage engine version 2.15(beta).
Spider is a Storage Engine for database sharding.
http://spiderformysql.com/

The main changes in this version are following.
This release is bug fix release.

Please see "99_change_logs.txt" in the download documents for more detail.

Enjoy!

The problem with a SQL RDBMS is SQL. It is easy to write SQL that misbehaves or does not behave as expected. Sometimes MySQL makes that too easy. Part 1 in this series introduced the steps to follow when testing select statements. This note will focus on insert, update and delete statements.

The standard QA practice (run EXPLAIN, run on a test server, deploy slowly) doesn't work. MySQL doesn't support EXPLAIN for insert, update and delete. Feature requests 14745 and 35355 have been open for some time to change this.

Fortunately, there are still things that can be done to verify the safety of a new insert, update or delete statement. Such a statement might be …

The NoSQL/relational database debate has been going on for quite some time. MariaDB, like MySQL is relational. And if you read these series of blog posts, you’ll realise that if you use MySQL correctly, you can achieve quite a lot.

1. It all starts with Kellan Elliott-McCrea with his introductory post on Using, Abusing and Scaling MySQL at Flickr. Follow the entire series.
2. He starts of the series with Ticket Servers: Distributed Unique Primary Keys on …

I had someone point out to me that some of the sample code I have used might be vulnerable to an insertion attack. So I feel it is time to address this subject.

First when using examples I try to just focus on the subject of the current blog and often strip a lot of things that are irrelevant to the point I am trying to make out. But now to the subject of keeping your code save.

If you write and SQL statement looking something like

lc_sql = “SELECT * from customer WHERE custno = ‘” + lc_custno + “‘”

Someone could enter “‘; TRUNCATE TABLE customer;’” resulting in  a SQL statement looking like

SELECT * from customer WHERE custno = ”; TRUNCATE TABLE customer; ”

Which could be quite disasterous. So to avoid this we could use parameterized queries which I cannot as I am using a seperate function to wrap around the SQLEXEC() function to do all kinds of things like …