Re: [HACKERS] view?

Jose' Soares wrote:

> Hi,
>
> Currently psql show views like:
>
> Database    = hygea
>  +------------------+----------------------------------+----------+
>  |  Owner           |             Relation             |   Type   |
>  +------------------+----------------------------------+----------+
>  | postgres         | abbattimenti                     | table    |
>  | postgres         | wattivita                        | view?    |
>  | postgres         | attivita_a                       | table    |
>
> because it seeks for relhasrules field and if you have a table (not a
> table) with a rule it thinks it is a view
> and displays "view?" instead of "table".
>
> I modified psql.c to use pg_get_viewdef() function to seek for views and
> now I can display only tables using \dt
> or only views using \dv like:hygea=> \dv
> [...]

    I suggest not to apply this patch

    1.  The  function  pg_get_viewdef()  is  definitely  too much
        overhead. In fact it must parse back  the  complete  view
        definition, doing many system table lookups, just to tell
        if this is a view or not.

    2.  The function pg_get_viewdef() is currently  out  of  sync
        with  the possible parsetrees for rule actions. CASE (and
        maybe some other constructs) aren't implemented and if it
        hit's on such a rule it will elog() out.

    Rules  on  SELECT  event are restricted totally to view rules
    since v6.4.  There can be only one rule  on  SELECT  that  is
    INSTEAD and selects exactly the attributes on one table.  And
    AFAIC this restriction will stay.  The  check  should  be  if
    there is a rule with event SELECT --> view.


Jan

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