
>TupleTables are just temporary data structures to hold transiently
>created tuples during execution of a query.  There's usually one for
>each plan node.
>
whats a 'plan node'?

>From: Tom Lane <tgl@sss.pgh.pa.us>
>To: "Jenny -" <nat_lazy@hotmail.com>
>CC: pgsql-hackers@postgresql.org
>Subject: Re: [HACKERS] row level lock and table level locks Date: Mon, 08 
>Sep 2003 12:49:51 -0400
>
>"Jenny -" <nat_lazy@hotmail.com> writes:
> > I found out that TupleTable stores per-tuple information(it stores
> > HeapTupleData) and that also there are multiple TupleTables in the db at 
>a
> > time.Based on what are diffrent TupleTables created?
>
>TupleTables are just temporary data structures to hold transiently
>created tuples during execution of a query.  There's usually one for
>each plan node.
>
>			regards, tom lane
>
>---------------------------(end of broadcast)---------------------------
>TIP 4: Don't 'kill -9' the postmaster

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Mon, 08 Sep 2003 10:17:46 -0700
"Jenny -" <nat_lazy@hotmail.com>
Re: row level lock and table level locks
On Mon, Sep 08, 2003 at 10:17:46AM -0700, Jenny - wrote:

> >TupleTables are just temporary data structures to hold transiently
> >created tuples during execution of a query.  There's usually one for
> >each plan node.

> whats a 'plan node'?

Have you tried reading the documentation, source code and the slides of
Tom and Bruce's presentations?  They all are very valuable resources.  I
believe there's a good set of slides by Bruce in
http://developer.postgresql.org that explain these things in a general
manner.  Armed with that you can try to read the source code.

-- 
Alvaro Herrera (<alvherre[a]dcc.uchile.cl>)
"I dream about dreams about dreams", sang the nightingale
under the pale moon (Sandman)

Mon, 8 Sep 2003 14:07:34 -0400
Alvaro Herrera <alvherre@dcc.uchile.cl>
Re: row level lock and table level locks