psql / tab-completion.c : patch proposals

Attached are two patches for psql's tab-completion.c.

The first cleans up a couple of minor errors and ommissions
and adds tab completion support to more slash commands, e.g.
\dv.

The second is an attempt to add tab completion for schemas
and fully qualified relation names (e.g. public.mytable ).
I think this covers the TODO-item:
"Allow psql to do table completion for SELECT * FROM schema_part and table
completion for SELECT * FROM schema_name."

This happens via union selects querying:
- relation_name in current search path;
- schema_name;
- schema.relation_name
matching the current input string.

E.g:
SELECT p[TAB]
will produce a list of all appropriate relation names in the current search
path which begin with 'p', and also all schema names which begin with 'p';
\d pub[TAB]
will produce any relation names in the current search path and also
any schema names beginning with 'pub';
\d public.[TAB]
will produce a list of all relations in the schema 'public';
\d public.my[TAB]
produces all relation names beginning with 'my' in schema 'public'.

It seems to work for me; comments, suggestions, particularly regarding
the coding and queries, are very welcome.

Note that tables, indexes, views and sequences relations in the
'pg_catalog' namespace are excluded even though they are in
the current search path. I found not doing this produced annoying behaviour
when expanding names beginning with 'p'. People who work with system
tables a lot may not like this though; I can look for another solution
if necessary.

The second patch must be applied after the first patch; it will not
apply against CVS. Can supply one big patch but feel it more sensible
to break up the changes into more digestible units.

Ian Barwick
barwick(at)gmx(dot)net