Re: Tab completion of SET TRANSACTION ISOLATION

Added to TODO:

o Prevent tab completion of SET TRANSACTION from querying the
database and therefore preventing the transaction isolation
level from being set.

Currently, SET <tab> causes a database lookup to check all
supported session variables. This query causes problems
because setting the transaction isolation level must be the
first statement of a transaction.

---------------------------------------------------------------------------

Greg Stark wrote:
> Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> writes:
>
> > Hm, that's a bit nasty.
> >
> > The only plan I can think of involves reading the list of available
> > variable names in advance and keeping it around. However, I'm not
> > sure I want psql issuing such a query at connection startup whether
> > or not the info will ever be used :-(
>
> Well, it could just lazily cache the data if it's ever fetched. That would at
> least limit the occurrence of this problem to only happening once per
> connection.
>
> psql could also hard code "SET TRANSACTION ISOLATION" specifically. If psql
> knew that "SET TRANS" completes to SET TRANSACTION and "SET TRANSACTION I"
> completes to "SET TRANSACTION ISOLATION" it could avoid doing the query at
> all.
>
> That would only fail if someone uses TAB to view the available completions for
> "SET" or any shorter string. And since transaction isolation is strangely
> absent from the list of completions that seems like not such a big concern. If
> he's doing that he's not going to find it anyways.
>
> --
> greg
>
>
> ---------------------------(end of broadcast)---------------------------
> TIP 6: explain analyze is your friend
>

--
Bruce Momjian | http://candle.pha.pa.us
pgman(at)candle(dot)pha(dot)pa(dot)us | (610) 359-1001
+ If your life is a hard drive, | 13 Roberts Road
+ Christ can be your backup. | Newtown Square, Pennsylvania 19073