Re: ToDo: show size of partitioned table

ne 7. 4. 2019 v 20:27 odesílatel Alvaro Herrera <alvherre(at)2ndquadrant(dot)com>
napsal:

> On 2019-Apr-07, Pavel Stehule wrote:
>
> > ne 7. 4. 2019 v 19:16 odesílatel Alvaro Herrera <
> alvherre(at)2ndquadrant(dot)com>
> > napsal:
> >
> > > Here.
> >
> > + 1
>
> BTW I'm not sure if you noticed, but I removed the error message "no
> partitioned relations found" when the result was empty. This was
> mimicking \d behavior (which was justified on historical grounds), and
> \drds behavior (which was justified on pattern ordering grounds); but I
> see nothing that justifies it for \dP, so let's make it behave like all
> the other commands and display an empty table.
>
> And there's an additional change to make. In the regression database,
> this returns an empty table:
>
> regression=# \dPi regress_indexing.pk5_pkey
> List of partitioned indexes
> Esquema | Nombre | Dueño | On table
> ---------+--------+-------+----------
> (0 filas)
>
> but the index does exist, and it is a partitioned one. So it should be
> displayed. In fact, if I add the "n" flag, it shows:
>
> regression=# \dPin regress_indexing.pk5_pkey
> List of partitioned indexes
> Esquema | Nombre | Dueño | Parent name |
> On table
>
> ------------------+----------+----------+--------------------------+----------------------
> regress_indexing | pk5_pkey | alvherre | regress_indexing.pk_pkey |
> regress_indexing.pk5
> (1 fila)
>
> I think the fact that \dPi doesn't show it is broken, and this fixes it:
>
> @@ -3946,7 +3946,8 @@ listPartitionedTables(const char *reltypes, const
> char *pattern, bool verbose)
> appendPQExpBufferStr(&buf, "''"); /* dummy */
> appendPQExpBufferStr(&buf, ")\n");
>
> - appendPQExpBufferStr(&buf, !showNested ? " AND NOT
> c.relispartition\n" : "\n");
> + appendPQExpBufferStr(&buf, !showNested && !pattern ?
> + " AND NOT
> c.relispartition\n" : "");
>
> if (!pattern)
> appendPQExpBufferStr(&buf, " AND n.nspname <>
> 'pg_catalog'\n"
>
> In order for this to display sanely, I added the "Parent name" column if
> either the "n" flag is shown or a pattern is given (previously it only
> appeared in the former case).
>

I am thinking about it and original behave and this new behave should be
expected (and unexpected too). We can go this way - I have not
counter-arguments, but yes, it is more consistent with some other commands,
pattern disables some other constraints.

It should be documented - Using any pattern in this case forces 'n' flag.

> Note that this changes the expected output in the test; now every test
> that uses a pattern displays *all* partitioned relations that match the
> pattern, not just top-level ones. I'm about +0.2 convinced that this is
> desirable, but my first example above tilts the scales to changing it as
> described.
>
> I noticed this while testing after messing with the tab completion as
> suggested by Justin: we already had Query_for_list_of_partitioned_tables
> (which you could have used), but since \dP works for both indexes and
> tables, I instead modified your new
> Query_for_list_of_partitioned_relations to list both relation kinds.
>
>
has sense.

> --
> Álvaro Herrera https://www.2ndQuadrant.com/
> PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
>