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Creating Stacked Line Graphs in R with ggplot2 21 Feb 2013 | 03:42 am
I spent a few hours yesterday banging my head against the wall trying to create stacked line graphs (aka area charts) using R. There are a number of tutorials available, but none resulted in the targe...
Sessions I’d like to see at Percona Live MySQL Conference and Expo 2013 13 Feb 2013 | 11:31 pm
I’ve finally gotten around to starting to write my presentations for PLMCE2013. So, in the spirit of procrastination, I went through all of the sessions and highlighted some of the ones that I want to...
Predicting Postgres Performance By Looking At Old MySQL Bugs 20 Sep 2012 | 10:54 pm
While putting PostgreSQL 9.2 through it’s paces, I noticed some behavior that was eerily familiar. Back in January of 2006, Peter Zaitsev opened a bug against MySQL 4.1 that complained of a comparison...
pg_stat_activity shows future queries! 12 Sep 2012 | 06:53 am
This morning I was working on getting some statistics on average transaction open time on a relatively underutilized host when I noticed some oddities. Periodically, I would see that my average durati...
Postgres unaware of it’s own connection limits? 6 Sep 2012 | 09:48 am
Normally I’d just file a bug with something like this, but there’s no PostgreSQL bug tracker. So I’m left with a blog post … I was doing some testing with PostgreSQL memory usage and needed to know wh...
Approximating Postgres Replication Delay 31 Aug 2012 | 04:32 am
Coming from the MySQL world, I’m used to being able to easily determine the replication delay (in seconds) via the SHOW SLAVE STATUS command: mysql> show slave status\G *************************** 1. ...
PostgreSQL 9.1 max_wal_senders – The Missing Documentation 9 Aug 2012 | 12:30 pm
When setting up Log Shipping or Streaming Replication with PostgreSQL 9.1, you’ll inevitably come across the max_wal_senders configuration variable. The docs on this are sparse, saying only: “Specifie...
Installing HandlerSocket on RHEL 6 + Percona-Server 5.5 in Five(ish) Easy Steps 29 Sep 2011 | 07:59 am
As a followup to my previous post on installing HandlerSocket on CentOS 5 + Percona-Server 5.1, I’ve been asked to provide an updated HOWTO for RHEL 6 + Percona-Server 5.5. Although very similar to th...
(More) Numbers Everyone Should Know 28 Sep 2011 | 11:58 am
By now, everybody should be aware of Jeff Dean’s Numbers Everyone Should Know: L1 cache reference 0.5 ns Branch mispredict 5 ns L2 cache reference 7 ns Mutex lock/unlock 100 ns Main memory reference 1...
HandlerSocket execute_multi Curiosities 5 Apr 2011 | 09:13 am
A post on the HandlerSocket-dev mailing list the other day got me thinking about the performance of MySQL’s IN() construct versus HandlerSocket’s execute_multi. So I started a little test, using MySQL...
