question Re: QlikView not using TEZ ? in Archives of Support Questions (Read Only)

QlikView not using TEZ ?

daniel_scheiner — Fri, 04 Nov 2016 21:56:17 GMT

Hi,

we have seen that only more complex (case, count,...) SELECT statements from Qlikview are being executed via TEZ.

All settings in Ambari are set to use TEZ by default.

Is this a Hortonworks issue?

Thank you!

Re: QlikView not using TEZ ?

KuldeepK — Fri, 04 Nov 2016 22:16:11 GMT

@Daniel Scheiner

In HDP, we have hive.execution.engine set to TEZ by default, hence all the complex queries gets executed via TEZ.

If you want, you can modify this property to 'mr'.

Hope this information helps.

Re: QlikView not using TEZ ?

daniel_scheiner — Fri, 11 Nov 2016 23:45:07 GMT

hive.execution.engine already is TEZ - we do not want MR due to its very very poor performance...

the problem appears to be with Qlik...

Re: QlikView not using TEZ ?

cstanca — Sat, 12 Nov 2016 01:21:56 GMT

@Daniel Scheiner

QlikView override the execution engine at the runtime. It uses a cost-based optimizer and based on its stats running the query with MR makes more sense. Reach to you QlikView support to learn the reasoning.

If this response helped, please vote and accept it as a best answer.

Re: QlikView not using TEZ ?

daniel_scheiner — Mon, 21 Nov 2016 21:30:33 GMT

i wanted to let you know the result of our analysis:

Qlik will use TEZ which considerably speeds up the request times - IF the SQL-statement is sufficiently complex! (i.e. use a count or sum command - as a dummy)

Re: QlikView not using TEZ ?

cstanca — Tue, 22 Nov 2016 00:33:02 GMT

@Daniel Scheiner

See my response from Nov 11 at 05:21 PM. It states the same, Cost Based Optimizer decides to use Tez for those queries where Tez can deliver faster that MR.