Am 31.01.2016 um 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
but only if you do *nothing else* i had servers going down by 50% append and 50% update a key-field after mail-confirmation and so 50% insert / 50 % updates + locked reads for display the page solution was to create a second table, append and update there and every 15 minutes via cron batch-insert into the main table in that case InnoDB was no option because the only table out of 6000 on that machine which woul dhave needed it and i hate this stupid global tablespace which exists even with files_per_table