MySQL auto purge

I have a HMI that will be installed in remote field location, collecting data in MySQL tables over time.  What tools does MySQL offer where I can set up for certain tables to be purged periodically weather based on a time period or on space.
Since this machine will be stand-alone I'm just looking for a way for this MySQL to manage itself to an extent just so the hard drive doesn't fill up.  we shoulnd't need more than 3 months history on data at the most.
cqr213Asked:
Who is Participating?

Improve company productivity with a Business Account.Sign Up

x
 
gr8gonzoConnect With a Mentor ConsultantCommented:
I would also try running a SELECT on that query first to make sure it's grabbing only the data you want to delete. Deletes are permanent!
0
 
nemws1Connect With a Mentor Database AdministratorCommented:
Usually, I would do this with 'cron' and not with MySQL inself, although it does have an event scheduler, you have a lot more control with cron (or a scheduled task if you're using windows).

More info on MySQL's event scheduler:   http://dev.mysql.com/doc/refman/5.1/en/events.html
0
 
cqr213Author Commented:
Can you please elaborate?
So by default will tables in a MySQL schema just append to new data or does it just add until it fill up all space?
0
Improve Your Query Performance Tuning

In this FREE six-day email course, you'll learn from Janis Griffin, Database Performance Evangelist. She'll teach 12 steps that you can use to optimize your queries as much as possible and see measurable results in your work. Get started today!

 
gr8gonzoConnect With a Mentor ConsultantCommented:
I would use a scripting language to create queries to analyze and drop data. For example, in PHP:

<?php
mysql_connect("localhost","username","password");
mysql_select_db("database_name");

mysql_query("DELETE FROM yourtable WHERE someDateTimeField <= NOW() - INTERVAL 3 MONTH");
?>
0
 
Ray PaseurCommented:
What's an HMI?
0
 
cqr213Author Commented:
Ok however I'm not familiar with PHP.  Is there a way for me to do this from inside Workbench?  I was hoping it was as easy as maybe doing a Scheduled task in windows or a event schedule in Workbench somehow..

HMI - Human Machine Interface
It's basically just a computer running software that controls mechanical devices via PLC's (I/O).
0
 
gr8gonzoConnect With a Mentor ConsultantCommented:
Man, I was certain it stood for a Hibernating Mammoth Inebriator. Twenty bucks down the drain.

You can also just create a SQL file with the commands you want to run and use Windows task scheduler to run a command like:

C:\path\to\mysql.exe --user=YourUsernameHere --password=PasswordHere --database=YourDatabase < C:\path\to\the\file.sql
0
 
FishMongerConnect With a Mentor Commented:
I'd partition the tables by date range and then have a cron job that kicks off a script that drops the older partition(s) and repartitions as needed.

Dropping partitions is more efficient than using select/delete queries.

RANGE Partitioning
0
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.