Predicate Pushdown

Dear Team

I am using latest dremio 3.2 version. I connected to two mysql databases which are in different servers. When i am executing the join query between tables in these to databases it is doing a full table scan. The ‘where’ condition which i am giving is not getting executed in db side it’s acting as filter while processing.

In my case there is large data on these tables so full table scan won’t be good. Please assist on this.

Thanks & Regards
Rahul

@Rahul,

Can you share the job profile?

Dear Ben

Please find the attached job profile

666c9d79-1044-43cb-b152-1314dac0d591.zip (7.5 KB)

Dear Ben

After checking the job profile did you got any clue regarding this?

Hi @Rahul,

Apologies for the delay.

You can try a couple of things:

  1. Don’t use the VDS @admin.student and @admin.student, but rather reference the queries defining those VDS directly in the join (as subqueries)

  2. Dremio should push the down the filter past the join, so this is unexpected. Please rerun the original query with verbose profile logging. To enable verbose profile logging, go to Admin -> Support -> scroll down to Support Keys and add planner.verbose_profile