Temporary Views

Hi all,

I'm thinking that temporary views should be pretty trivial to
implement.

* Allow temporary views

This should be as simple as modifying gram.y (to set
ViewStmt->view->istemp) and some logic in RemoveTempRelations() to remove
the view's rule

* Require view using temporary tables to be temporary views

This is the non-trivial part. If you are creating a view on just a
temporary table there's no problem. But what happens when do the
following?

CREATE VIEW abc AS select * from tab1,tab2,temp_tab3 ...

SQL99 avoids this with syntax rule 6 of 11.21 <view definition>

No <table reference> generally contained in the <query expression> shall
identify any declared local temporary table.

There are a few ways it could be implemented:

1) SQL99
2) Views whose <query epression> contains one or more <table references>
to temporary tables are created as temporary views
3) Views whose <query epression> contains one or more <table references>
to temporary tables must be explicitly include the TEMP[ORARY] syntax.

Thoughts?

Gavin