1.8 or 1.9? MySQL or PostgreSQL?

1.8 or 1.9? MySQL or PostgreSQL?

by Sergei Yegorov -
Number of replies: 11
I have been playing about with various versions of moodle.
We’re starting a production site now I need some advice on:

  • Moodle 1.8 or 1.9. I’m quite happy with 1.8 features, but it was said somewhere here that 1.9 consumes less system resources.
The forecast:
- 300 teachers/courses
- 45000 students
- about 500 concurrent users taking quizzes.

Average of ratings: -
In reply to Sergei Yegorov

Re: 1.8 or 1.9? MySQL or PostgreSQL?

by Anthony Borrow -
Picture of Core developers Picture of Plugin developers Picture of Testers
Sergei - If it were me, I would do 1.9 and PostgreSQL. With 1.9 I know that work has been done to improve the performance (i.e. fewer queries). A possible drawback for 1.9, is that the gradebook is new but since you are not migrating a site your teachers will be learning from scratch and won't be saying that they liked the old gradebook better. As for the database, I've read that PostgreSQL seems to be more configurable for larger sites. Of course some of it depends on your own comfort and familiarity with the various databases as you will want something you are comfortable maintaining. It sounds like you are familiar enough with installing Moodle that keeping your code 1.8 or 1.9 (beta) patched up will not be a problem. Best of luck with launching your production site and let us know if you have any questions. Peace - Anthony
Average of ratings: -
In reply to Anthony Borrow

Re: 1.8 or 1.9? MySQL or PostgreSQL?

by Sergei Yegorov -
Thank you, Anthony! I can install Moodle on my own but I can't mange the databases. We're still on VPS and I have to rely on default database settings.
Average of ratings: -
In reply to Sergei Yegorov

Re: 1.8 or 1.9? MySQL or PostgreSQL?

by Anthony Borrow -
Picture of Core developers Picture of Plugin developers Picture of Testers
I'm not sure which performs best for large installations "out of the box". My guess would be PostgreSQL but it is merely a guess and not based on experience. I know that on a much smaller installation (about 1200 users but fairly active - for the last month averaging over 37 queries per second), I have been pleased with mysql and did not have to do any special configuration. Peace - Anthony
Average of ratings: -
In reply to Sergei Yegorov

Re: 1.8 or 1.9? MySQL or PostgreSQL?

by Martín Langhoff -
At 45K users, and high concurrency I'd recommend PostgreSQL 8.2 or the just-released 8.3 (which I haven't tested, but comes out in some tests as twice as fast as 8.2). MySQL will probably do (specially a v5.x) but growing from there will be painful, and you have to deal with the corrupt indexes issues that tend to appear under high load.

And for that workload I would not even try 1.8 - 1.9 is the ticket.
Average of ratings: -
In reply to Martín Langhoff

Re: 1.8 or 1.9? MySQL or PostgreSQL?

by Mark Hilliard -
Martin,
From I have read it appears you have worked on the core of the newer Moodle version 1.9x (and v 1.8.x?) with important query optimizations.

If you have just a few minutes can you elaborate the major short points of what the major changes made that helped to "speed optimize" these versions?

It would also be very helpful if you could share anything you know about the relative "speed/responsiveness" of Moodle 1.7 to 1.8 to 1.9

Many of us have held off major upgrades based on speed problems with early 1.8 and it would be invaluable to get your impression of their responsiveness in the latest releases now offered. Thanks if you have a few minutes or can point to helpful links you know...

Mark H.
MPls, MN
Average of ratings: -
In reply to Mark Hilliard

Re: 1.8 or 1.9? MySQL or PostgreSQL?

by Martín Langhoff -
Mark - Google has what you're after -- I've posted it in the General Developers forum under a thread discussing accesslib wink
Average of ratings: -
In reply to Martín Langhoff

Re: 1.8 or 1.9? MySQL or PostgreSQL?

by Sergei Yegorov -
Martin - Thank you for reply. Tried to find the thread - failed mixed

Thank you all. Think, we’ll start with 1.9 + MySQL. Wait for Postgre 8.3 tests. Is it possible to migrate to Postgre later when we grow enough and have our own server(s)? The only things which are crucial are
questions, all backed up as Moodle XML files.
Teachers’ files (word, mp3),
Users – login, password. Grades and attempts are not important as the school year is over.

Average of ratings: -
In reply to Martín Langhoff

Odp: Re: 1.8 or 1.9? MySQL or PostgreSQL?

by Bartosz Cisek -
I'm targeting in simillar to Sergei instalation and I've chosen Postgres. When talking about Moodle version I'll rather stick to 1.8.x because I'm a bit afraid of "beta" status of 1.9 branch.
Average of ratings: -
In reply to Bartosz Cisek

Re: Odp: Re: 1.8 or 1.9? MySQL or PostgreSQL?

by Sergei Yegorov -
Bartosz - Are you happy with Postgre?
Average of ratings: -
In reply to Sergei Yegorov

Odp: Re: Odp: Re: 1.8 or 1.9? MySQL or PostgreSQL?

by Bartosz Cisek -
Hi,

Till now I don't have any special problems except migration from mysql which is a bit painfull (maybe because of my lack of experience smile

My main argument when taking a decision to deploy Postgres was that it manages a lot better with high load than mysql do.

Additionaly reading several articles about mysql approach to clustering gave me some image about mysql's approach to ACID which was not acceptable for me.

Mysql's problems with corrupting indexes under high load may be also worth to mention.

Average of ratings: -
In reply to Bartosz Cisek

Re: Odp: Re: Odp: Re: 1.8 or 1.9? MySQL or PostgreSQL?

by Sergei Yegorov -
Make a separate Moodle instalation on Postgre 8.3.
Course restore from MySQL backup went well.
Average of ratings: -