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


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


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/
> lockingdeadlocking-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/
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