Re: Parent/child context relation in pg_get_backend_memory_contexts()

I reviewed v3 patch and here are some minor comments:

> +     <row>
> +      <entry role="catalog_table_entry"><para
> role="column_definition">
> +       <structfield>path</structfield> <type>int4</type>

Should 'int4' be 'int4[]'?
Other system catalog columns such as pg_groups.grolist distinguish
whther the type is a array or not.

> +       Path to reach the current context from TopMemoryContext.
> Context ids in
> +       this list represents all parents of the current context. This
> can be
> +       used to build the parent and child relation.

It seems last "." is not necessary considering other explanations for
each field end without it.

+                                const char *parent, int level, int
*context_id,
+                                List *path, Size
*total_bytes_inc_chidlren)

'chidlren' -> 'children'

+   elog(LOG, "pg_get_backend_memory_contexts called");

Is this message necessary?

There was warning when applying the patch:

   % git apply
../patch/pg_backend_memory_context_refine/v3-0001-Adding-id-parent_id-into-pg_backend_memory_contex.patch

../patch/pg_backend_memory_context_refine/v3-0001-Adding-id-parent_id-into-pg_backend_memory_contex.patch:282:
trailing whitespace.
   select count(*) > 0

../patch/pg_backend_memory_context_refine/v3-0001-Adding-id-parent_id-into-pg_backend_memory_contex.patch:283:
trailing whitespace.
   from contexts
   warning: 2 lines add whitespace errors.