Re: Enhancing Memory Context Statistics Reporting

Hi,

Thanks for updating the patch and here are some comments:

'path' column of pg_get_process_memory_contexts() begins with 0, but
that column of pg_backend_memory_contexts view begins with 1:

=# select path FROM pg_get_process_memory_contexts('20271', false);
path
-------
{0}
{0,1}
{0,2}
..

=# select path from pg_backend_memory_contexts;
path
-------
{1}
{1,2}
{1,3}
..asdf asdf

Would it be better to begin with 1 to make them consistent?

pg_log_backend_memory_contexts() does not allow non-superusers to
execute by default since it can peek at other session information.
pg_get_process_memory_contexts() does not have this restriction, but
wouldn't it be necessary?

When the target pid is the local backend, the HINT suggests using
pg_get_backend_memory_contexts(), but this function is not described in
the manual.
How about suggesting pg_backend_memory_contexts view instead?

=# select pg_get_process_memory_contexts('27041', false);
WARNING: cannot return statistics for local backend
HINT: Use pg_get_backend_memory_contexts instead

There are no explanations about 'num_agg_contexts', but I thought the
explanation like below would be useful.

> I have added this information as a column named "num_agg_contexts",
> which indicates
> the number of contexts whose statistics have been aggregated/added for
> a particular output.

git apply caused some warnings:

$ git apply
v7-Function-to-report-memory-context-stats-of-any-backe.patch
v7-Function-to-report-memory-context-stats-of-any-backe.patch:71: space
before tab in indent.
Requests to return the memory contexts of the backend with the
v7-Function-to-report-memory-context-stats-of-any-backe.patch:72: space
before tab in indent.
specified process ID. This function can send the request to
v7-Function-to-report-memory-context-stats-of-any-backe.patch:ldmv:
space before tab in indent.
both the backends and auxiliary processes. After receiving the
memory
v7-Function-to-report-memory-context-stats-of-any-backe.patch:74: space
before tab in indent.
contexts from the process, it returns the result as one row per
v7-Function-to-report-memory-context-stats-of-any-backe.patch:75: space
before tab in indent.
context. When get_summary is true, memory contexts at level 0

--
Regards,

--
Atsushi Torikoshi
Seconded from NTT DATA GROUP CORPORATION to SRA OSS K.K.