Am 31.01.2016 09:09, schrieb Sergei Golubchik: > 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. >
This is was we actualy do with, never delete, very few updates and read is no performance problem. "crash sensitive" translates into: We had 3-4 occassions where an full backup was needed, and all had all to do with immoDB tables broken beyond repair. re, wh _______________________________________________ Mailing list: https://launchpad.net/~maria-discuss Post to : [email protected] Unsubscribe : https://launchpad.net/~maria-discuss More help : https://help.launchpad.net/ListHelp
