maria-discuss team mailing list archive

[Sergei Golubchik <serg@xxxxxxxxxxx>]

Hi, Reindl!

On Jan 30, Reindl Harald wrote:
> 
> 
> Am 30.01.2016 um 21:07 schrieb walter harms:
> > Aktualy I do now some profiling now we want to see the differences
> > when switching 31-1.  We used myISAM since the biggest problem is
> > speed and immoDB showed to be crash sensitive.  We store long time
> > series data so the system is writing data all the time.
> 
> for "writing data all the time" MyISAM is for sure a completly wrong 
> decision because the performance strength of MyISAM was always on 
> most-read workloads
> 
> MyISAM *always* does a *complete table lock* for writes and don't allow 
> concurrent writes without locking - that don't scale when you write all 
> day long and there are table locks all day long

MyISAM should perform very good if inserts are *append only* (no updates
or deletes). In this case MyISAM will not use an exclusive table lock
and concurrent reads will be allowed.

It is typical for some kind of logging - one threads inserts *all the
time* other threads are reading the data concurrently.

In fact, this is one of the use cases MyISAM was written for.

Regards,
Sergei
Chief Architect MariaDB
and security@xxxxxxxxxxx