← Back to team overview

maria-developers team mailing list archive

Re: Accessing read records during join for condition pushdown


Hi, Berrocal,!

On Jul 06, Berrocal, Eduardo wrote:
> Hello list (first email here, hopefully sending it to the right address),
> I have been trying to solve this problem for a while now, and I am
> stuck. I wonder if what I am trying to do is even possible.
> I am implementing a new storage engine which handles engine condition
> pushdown. Now, when MariaDB is working on a JOIN using more than one
> table (for simplicity, let's assume 2), how can I access the read
> records for table 1 when working on a condition pushdown for table 2?
> When joining like this: table1.field1 = table2.field1, I can see 2
> Item objects of type FIELD in the condition. However, I can't find
> where the read records for table1 are so I can effectively filter
> records in table2 by those values.

if f1 is Item_field for table1.field1, then generally


is the current record for the table1, and


is the pointer to the field1 value in that currect record

> Thanks a lot for your help,
> Eduardo Berrocal García de Carellán
> Senior Software Engineer
> Intel Corporation  |  intel.com<http://intel.com/>

VP of MariaDB Server Engineering
and security@xxxxxxxxxxx

Follow ups