Re: query_id: jumble names of temp tables for better pg_stat_statement UX

Michael Paquier <michael(at)paquier(dot)xyz> writes:
> [ v6-0001-Add-custom-query-jumble-function-for-RangeTblEntr.patch ]

Couple of minor review comments ...

* In 5ac462e2b, this bit:

# node type
- if (($t =~ /^(\w+)\*$/ or $t =~ /^struct\s+(\w+)\*$/)
+ if ($query_jumble_custom)
+ {
+ # Custom function that applies to one field of a node.
+ print $jff "\tJUMBLE_CUSTOM($n, $f);\n";
+ }
+ elsif (($t =~ /^(\w+)\*$/ or $t =~ /^struct\s+(\w+)\*$/)

fails to honor $query_jumble_ignore as the other if-branches do.
Perhaps it's unlikely that a node would have both query_jumble_custom
and query_jumble_ignore annotations, but still, the script would emit
completely incorrect code if it did. Also, the "# node type" comment
should probably be moved down to within the first "elsif" block.

* In the v6 patch, this doesn't read very smoothly:

+ * Expanded reference names. This uses a custom query jumble function so
+ * as the table name is included in the computation, not its list of
+ * columns.

Perhaps better

+ * Expanded reference names. This uses a custom query jumble function so
+ * that the table name is included in the computation, but not its list of
+ * columns.

* Also, here:

+ considered the same. However, if the alias for a table is different
+ for semantically similar queries, these queries will be considered
+ distinct.

I'd change "semantically similar queries" to "otherwise-similar
queries"; I think writing "semantically" will just confuse people.

Otherwise LGTM.

regards, tom lane