Re: Extended Statistics set/restore/clear functions.

some of the switch->default, default don't have ``break``.

The compiler doesn't require them, but I see that we do use them in a lot of places, so I'll incorporate this.

 

+ for (int i = 0; i < nitems; i++)
+ {
+ MVNDistinctItem *item = parse_state.distinct_items->elements[i].ptr_value;

exposing the ptr_value seems not a good idea, we can foreach_ptr
the attached patch using foreach_ptr.

I didn't like this because it makes getting the index value harder, and the index value is needed in lots of places. Instead I used list_nth() and list_nth_int().

 

 

in function pg_ndistinct_in some errsave can change to ereturn.
(I didn't do this part, though).

-0.25

There's something that I like about the consistency of errsave() followed by a return that makes it clear that "the function ends here" that I don't get from ereturn().

What I would really like, is a way to generate unique (but translated) errdetail values, and move the errsave/ereturn to after the switch statement.

 

+ /*
+ * The attnum cannot be zero a negative number beyond the number of the
+ * possible expressions.
+ */
+ if (attnum == 0 || attnum < (0-STATS_MAX_DIMENSIONS))
+ {
+ errsave(parse->escontext,
+ errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+ errmsg("malformed pg_ndistinct: \"%s\"", parse->str),
+ errdetail("Invalid \"%s\" element: %d.",
+ PG_NDISTINCT_KEY_ATTRIBUTES, attnum));
+ return JSON_SEM_ACTION_FAILED;
+ }
This part had no coverage tests, so I added a few.

+1 

 

as mentioned before
+ errsave(parse->escontext,
+ errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+ errmsg("malformed pg_ndistinct: \"%s\"", parse->str),
+ errdetail("The \"%s\" key must contain an array of at least %d "
+  "and no more than %d attributes.",
+  PG_NDISTINCT_KEY_NDISTINCT, 2, STATS_MAX_DIMENSIONS));
here PG_NDISTINCT_KEY_NDISTINCT, should be PG_NDISTINCT_KEY_ATTRIBUTES.

+1

 

Did similar things to pg_dependencies.