by Peter Zaitsev | Jul 9, 2008 | Hardware and Storage
One of our customers was setting up box for MySQL LVM backups. The box had 2 RAID volumes (internal drives and enclosure) with database being stored on enclosure drives and internal drives used pretty much for OS and logs (database grew too large and so was moved to...
by Peter Zaitsev | Jul 8, 2008 | Insight for DBAs
Baron recently wrote about very helpful but often forgotten about “Pager” feature of command line client. There is another one which falls into the same list – the –tee option. Specifying –tee=/path/to/file.log you can get all session...
by Peter Zaitsev | Jun 30, 2008 | Insight for DBAs
I have been helping customer today to resolve his lockups in production by downgrading from MySQL 5.1.25 to 5.0 We have other customers (and our own projects as well) which run on MySQL 5.1 successfully but I can’t it is on par with MySQL 5.0 stability yet. This...
by Vadim Tkachenko | Jun 22, 2008 | Percona Events
Why one may wonder, it’s just Swedish beer (State of Doplhin, MySQL UC 2006). One week ago Jim Starkey sent message http://www.firebirdnews.org/?p=1742 so he will not work for MySQL anymore and starting new project. While that’s fully Jim Starkey’s...
by Vadim Tkachenko | Jun 17, 2008 | Insight for Developers
We often recommend to set lighttpd in front of apache to handle http requests (more about https://www.percona.com/blog/speedup-your-lamp-stack-with-lighttpd/ ) , redirect dynamic requests to apache and handle static files by itself. I just gathered step-by-step...
by Peter Zaitsev | Jun 9, 2008 | Hardware and Storage
We know MySQL Backups using LVM are pretty cool (check out mylvmbackup) or MMM though it is quite typical LVM is not configurable properly to be usable for MySQL Backups. Quite frequently I find LVM installed on the system but no free space left to be used as snapshot...
by Peter Zaitsev | Jun 5, 2008 | Insight for DBAs
Backing up MySQL Database most people compress them – which can make a good sense in terms of backup and recovery speed as well as space needed or be a serious bottleneck depending on circumstances and approach used. First I should mention this question mainly...
by Peter Zaitsev | Jun 2, 2008 | Uncategorized
I was working with the customer today investigating MySQL over DRBD performance issues. His basic question was why there is so much overhead with DRBD in my case, while it is said there should be no more than 30% overhead when DRBD is used. The truth is –...
by Peter Zaitsev | May 28, 2008 | Insight for DBAs
MySQL Server does not require you to specify name of the index if you’re running ALTER TABLE statement – it is optional. Though what might be good practical reasons to specify the key name or omit ? Things what you should be looking at is how MySQL names...
by Peter Zaitsev | May 24, 2008 | Insight for DBAs
I’m not big fan on flow control functions like IF or CASE used in MySQL Queries as they are often abused used to create queries which are poorly readable as well as can hardly be optimized well by MySQL Optimizer. One way I find IF statement very useful is...
by Peter Zaitsev | May 20, 2008 | Insight for Developers
Sometimes due to programming error or due to very complex query you can get your PHP script running too long, well after user stopped waiting for the page to render and went browsing other sites. Looking at Server-Status I’ve seen scripts executing for hours...
by Peter Zaitsev | May 1, 2008 | Insight for DBAs
In the previous post I mentioned a way I use to preload Clustered Index (data) for Innodb tables. Though I thought this topic would benefit from a bit more information. But lest first start with feature request for Innodb Team: All ways I mention here are hacks and...
by Peter Zaitsev | May 1, 2008 | Insight for DBAs
Recently I was working with the customer who need quick warmup – to get Innodb table fetched in memory as fast as possible to get good in memory access performance. To do it I run the query: “SELECT count(*) FROM tbl WHERE non_idx_col=0” I use this...
by Peter Zaitsev | May 1, 2008 | Uncategorized
Sun is aggressively pushing T2000 as Scalable MySQL Platforms, and indeed it is Scalable in terms of high concurrency workloads – it is able to execute a lot of concurrent threads and so speed gain from 1 thread to say 32 thread will be significant. But thing a...
by Peter Zaitsev | Apr 28, 2008 | Insight for DBAs
Well these days we see a lot of post for and against (more, more) using of MySQL and DRBD as a high availability practice. I personally think DRBD has its place but there are far more cases when other techniques would work much better for variety of reasons. First let...
by Peter Zaitsev | Apr 26, 2008 | Hardware and Storage
Let us talk few more about disks. You might have read my previous post and Matt’s Reply and it looks like there are few more things to clarify and explain. Before I get to main topic of the article lets comment on IO vs Disk question. If you look at Disk Based...
by Vadim Tkachenko | Apr 23, 2008 | Insight for DBAs
New features of InnoDB – compression format and fast index creation sound so promising so I spent some time to research time and sizes on data we have on our production. The schema of one of shards is CREATE TABLE `article87` ( `id` bigint(20) unsigned NOT NULL,...
by Vadim Tkachenko | Apr 20, 2008 | Insight for DBAs
It seems there is interesting problem with compatibility of MySQL binaries and binaries of third-party plugins. I personally found and there is confirmation from InnoDB team that current InnoDB-plugin binaries do not work with lastest 5.1.24-rc binaries. It was very...
by Peter Zaitsev | Apr 6, 2008 | Insight for DBAs
So you’re running dedicated MySQL Linux box with plenty of memory, so the good question arises if you should have swap file enabled or disable it ? I’ve seen production successfully running on boxes both with and without swap file so it is not the question...
by Peter Zaitsev | Apr 4, 2008 | Insight for Developers
We have an application which stores massive amount of urls. To save on indexes instead of using URL we index CRC32 of the URL which allows to find matching urls quickly. There is a bit of chance there would be some false positives but these are filtered out after...
