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

On Thu, Mar 7, 2019 at 8:20 PM amul sul <sulamul@gmail.com> wrote:

On Thu, Mar 7, 2019 at 1:02 PM amul sul <sulamul@gmail.com> wrote:

Thanks Rajkumar,

I am looking into this.

The crash happens when none of the if-else branch of handle_missing_partition()

evaluates and returns merged_index unassigned.

Let me explain, in Rajkumar 's test case, the join type is JOIN_INNER.  When

only outer rel has null partition, merge_null_partitions() function calls

handle_missing_partition() with missing_side_inner = false and

missing_side_outer = false

Both missing_side_ variables being false when the NULL partition is missing on the inner side looks suspicious. I guess from the variable names that the missing_side_inner should be true in this case. 

 

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.