Last night’s meeting was about ptop and Mark Wong’s efforts to make an interactive, command-line tool for monitoring the current status of a PostgreSQL database.
For our meeting, Mark set up a test operating system on a USB drive, and bravely demo’d his new software.
Mark got the idea for ptop a few months ago, and went looking for the source code to top to get started. After a few days of hacking, he had a some useful features he wanted to share. So, he’s set up a project and started gathering developers:
http://pgfoundry.org/projects/ptop
The features currently supported include displaying:
- Current queries
- Query plans
- Locks
- User table statistics
- User index statistics
One feature I particularly liked was showing deltas of statistics over time. So you set your ptop sampling interval to some value (i.e. 5 seconds) and then you can see, for example, user table statics
changing over time. This is something I wrote some perl scripts for, but would love to have as a standard utility. Particularly if I could log/graph it.
Currently, ptop is only compiling on Linux. I really want it on Mac OS X.
We came up with a short list of desired features for the next revision of ptop:
- Change command line options to match psql (-U for user, -p for port, etc)
- Add command to show table (basically \dt [tablename]) for non-query processes
- Enable arrow keys to move around in the content to select, instead
of cut/paste process ID - Log the stats deltas over time (i would be very interested in this)
- Change lock query to use an OUTER JOIN to show “waiting” locks that
aren’t granted
And just a general question that came up:
- Is it possible to peek at a currently executing SELECT statement’s plan?
– We all agreed that this would be awesome.
Thanks for a great meeting.
Thank you Mark & Gabrielle for sending out meeting announcements this month.
NEXT MEETING: DIFFERENT DATE AND TIME!
December Coders Bash
Tuesday, December 11, 2007
CubeSpace, 622 SE Grand Ave., Portland OR 97214
Sam from the PHP Users group started organizing a group event in
December, inviting folks from all the different users groups to come
and socialize.
ALSO a HACKATHON:
Gabrielle, Mark and I thought it would be awesome to have a ptop HackAThon the weekend after Thanksgiving. Some possible features we’d work on are below. Anyone interested? Get in touch. I was thinking the early afternoon on Saturday, or early evening on Sunday.