Re: [HACKERS] advanced partition matching algorithm forpartition-wise join

Attached version is rebase atop of the latest master head(fdc7efcc30), also

incorporates the Ashutosh's suggestion, thanks.

Regards,

Amul

On Mon, Mar 11, 2019 at 10:14 PM Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> wrote:

On Mon, Mar 11, 2019 at 10:40 AM amul sul <sulamul@gmail.com> wrote:

All the places from where this handle_missing_partition() get called

have the following code to decide the value for missing_side_outer/_inner which

I yet to understand. Do you think this has some flaw?

        /*  

         * For a FULL join, inner relation acts as both OUTER and INNER

         * relation.  For LEFT and ANTI join the inner relation acts as

         * INNER relation. For INNER and SEMI join OUTER and INNER

         * differentiation is immaterial.

         */

        missing_side_inner = (jointype == JOIN_FULL ||

                              jointype == JOIN_LEFT ||

                              jointype == JOIN_ANTI);

        missing_side_outer = (jointype == JOIN_FULL);

I was wrong, sorry. The comment says it all.

 

 

argument value which fails to set merged_index.

In the attached patch, I tried to fix this case by setting merged_index

explicitly which fixes the reported crash. 

I expect handle_missing_partition() to set the merged_index always. In your patches, I don't see that function in your patches is setting it explicitly. If we are setting merged_index explicitly somewhere else, other places may miss that explicit assignment. So it's better to move it inside this function.

 

Ok, that can be fixed.  

Similarly, I think merge_null_partitions should set null_index instead of

asserting when null partitions missing from both the side, make sense?

I think not. null_index, once set shouldn't change and hence does not change with each pair of partitions being matched. So, it makes sense to make sure that null_index remains invalid if none of the tables have null partition.

--

Best Wishes,

Ashutosh Bapat