← Back to team overview

maria-discuss team mailing list archive

Re: New Question: Locking/deadlocking on temp tables?


Oh yeah, this stupid system where I have to log into the web.  So much
stupid around here.

On Fri, Aug 19, 2016 at 11:52 PM, Justin Swanhart <greenlion@xxxxxxxxx>

> If you are using Galera, then aborted transactions due to lock conflict
> are reported as deadlocks.
> Temporary tables are not shared between connections and can not cause
> deadlocks.
> --Justin
> On Fri, Aug 19, 2016 at 7:50 PM, AskMonty KB <noreply@xxxxxxxxxxxx> wrote:
>> Hello,
>> A new question has been asked in "MariaDB Knowledge Base" by
>> WebtrendsData. Please answer it at http://mariadb.com/kb/en/locki
>> ngdeadlocking-on-temp-tables/ as the person asking the question may not
>> be subscribed to the mailing list.
>> --------------------------------
>> Hello - I am coming up to speed on MariaDB, I have a MS Sql Server and
>> Hadoop background but we are starting to use MariaDB heavily. We have some
>> queries that hit tables with mediumtext datatype columns. My understanding
>> is these types of queries will always generate temp tables directly to disk
>> (because of the text/blob types). I've confirmed our temp table engine is
>> Aria.
>> From what I've read, in the mysql world, this situation would end up with
>> a MyIsam table on disk, which does not have row locking, only table
>> locking. I've tried looking for info on how Aria tables would handle this
>> as I suspect we are getting deadlocks on these tables. Our application is
>> reporting many database deadlocks, our entire database is all ExtraDB
>> tables, yet SHOW ENGINE INNODB STATUS does not report any deadlocks, which
>> leads me to think it is the temp tables.
>> So I guess my question is, does the Aria engine do row locking? Is it
>> possible to get a status similar to SHOW ENGINE INNODB STATUS? Please
>> forgive me if this is painfully obvious or unclear (I'm still learning!),
>> and thank you for your time.
>> -Aaron
>> --------------------------------
>> To view or answer this question please visit:
>> http://mariadb.com/kb/en/lockingdeadlocking-on-temp-tables/
>> _______________________________________________
>> Mailing list: https://launchpad.net/~maria-discuss
>> Post to     : maria-discuss@xxxxxxxxxxxxxxxxxxx
>> Unsubscribe : https://launchpad.net/~maria-discuss
>> More help   : https://help.launchpad.net/ListHelp

Follow ups