Re: [HACKERS] Partition-wise join for join between (declaratively)partitioned tables

On Wed, Sep 20, 2017 at 9:44 AM, Thomas Munro
<thomas.munro@enterprisedb.com> wrote:
> 2.  What queries in the 0008 patch are hitting lines that 0007 doesn't hit?
>
> I thought about how to answer questions like this and came up with a
> shell script that (1) makes computers run really hot for quite a long
> time and (2) tells you which blocks of SQL hit which lines of C.
> Please find attached the shell script and its output.  The .sql files
> have been annotated with "block" numbers (blocks being chunks of SQL
> stuff separated by blank lines), and the C files annotated with
> references to those block numbers where A<n> = block <n>
> partition_join.sql and B<n> = block <n> in partition_join_extras.sql.
>
> Then to find lines that B queries hit but A queries don't and know
> which particular queries hit them, you might use something like:
>
>   grep -v 'SQL blocks: .*A[0-9]' < joinpath.c.aggregated_coverage | \
>   grep 'SQL blocks: .*B[0-9]'
>

Thanks for this. It generates a lot of output (970 lines over all the
coverage files). It will take some time for getting anything
meaningful out of this. May be there's some faster way by looking at
the lines that are covered by B but not A. BTW, I checked those lines
to see if there could be any bug there. But I don't see what could go
wrong with those lines.