Re: Small question - Mailing list pgsql-general

From Bruce Momjian
Subject Re: Small question
Date
Msg-id 200203221925.g2MJPOL26910@candle.pha.pa.us
Whole thread Raw
In response to Re: Small question  (Jan Wieck <janwieck@yahoo.com>)
List pgsql-general
Jan Wieck wrote:
> Bruce Momjian wrote:
> > Tom Lane wrote:
> > > Jan Wieck <janwieck@yahoo.com> writes:
> > > > Joep deVocht wrote:
> > > >> Is there a way to determine whether a transaction
> > > >> is started and not ended yet?
> > >
> > > >     I think it's time to add  a  little  boolean  function,  that
> > > >     actually  returns IsTransactionBlock(), and have a libpq side
> > > >     wrapper around PQfn() calling it.
> > >
> > > If you're in TRANSACTION ABORT state, I do not think that will work.
> > >
> > > Offhand this seems more of a protocol issue.  A straightforward solution
> > > would be to add a status indicator (with three states: out of
> > > transaction, in transaction, in aborted transaction) to the
> > > ReadyForQuery message, but we can't do that without a protocol change,
> > > which is probably more trouble than it's worth.
> >
> > Yes, I was wondering if it was worth having the client call the function
> > at the end of every query.
>
>     Who  said  that  it'll  be called after every query?  It will
>     only be called when the  application  asks  for  the  current
>     state. Sort of client side
>
>         bool PQisTransactionBlock(PGconn *conn);
>
>     I don't really see how that functionality could be a problem.

I just thought that most applications that need to know the state need
to know for almost every new query.  We had the request to update the
psql prompt with transaction status, and clearly the call would be
needed frequently.

--
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026

pgsql-general by date:

Previous
From: Jan Wieck
Date:
Subject: Re: Small question
Next
From: Tom Lane
Date:
Subject: Re: Small question