On Wed, 2005-10-26 at 11:14, Gregory Youngblood wrote:
> Talking with various people that ran postgres at different times, one
> thing they always come back with in why mysql is so much better:
> postgresql corrupts too easily and you lose your data.
>
> Personally, I've not seen corruption in postgres since 5.x or 6.x
> versions from several years ago. And, I've seen corruption on mysql
> (though I could not isolate between a reiserfs or mysql problem - both
> with supposedly stable releases installed as part of a distro).
>
> Is corruption a problem? I don't think so - but I want to make sure I
> haven't had my head in the sand for a while. :) I realize this
> instance appears to be on Windows, which is relatively new as a native
> Windows program. I'm really after the answer on more mature platforms
> (including Linux).
I have been using PostgreSQL since version 6.5.2. There are many people
on this list that have been using it longer than that. In all that
time, I've had exactly zero problems with data corruption. Of course,
every server I've run PostgreSQL on has been burnt in for at least a
week of heavy testing, and they've all had SCSI drives, and if they had
RAID controllers they all had battery backed cache.
Every machine was tested by running pg_bench for many days, about 100
clients wide, while doing other, more general work at the same time. A
part of the testing was to switch the machine off many times while it
was committing to the database, often forcing a flush before pulling the
plug.
I found quickly that IDE drives are not reliable with the cache turned
on, and are too slow for most production purposes without the cache.
So, SCSI was (and apparently still is) the only way to go.
Now, I'm willing to bet that PostgreSQL is more likely to notice
corruption and report it than MySQL. I wonder if MySQL can detect most
simple single bit errors or not? I'd have to do some testing on it to
see if it can detect such errors easily.
I'd much rather have a database that simply stops and reports a data
corruption error than one that doesn't notice, wouldn't you?