Re: updateable cursors & visibility - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: updateable cursors & visibility
Date
Msg-id 200303282333.h2SNXnL01679@candle.pha.pa.us
Whole thread Raw
In response to Re: updateable cursors & visibility  ("Hiroshi Inoue" <Inoue@tpf.co.jp>)
Responses Re: updateable cursors & visibility  ("Hiroshi Inoue" <Inoue@tpf.co.jp>)
List pgsql-hackers
Hiroshi Inoue wrote:
> > > If the cursor is INSENSITIVE, it mustn't see the row ?
> > 
> > Right.
> 
> If so, isn't the difference between SENSITIVE and INSENSITIVE extreme ?

Yes.

> Why do you or Peter refer to ASENSITIVE little ?

Not sure --- ASENSITIVE seems to be "do whatever you want", which is
always good.

> And what does the following mean ? It is placed just before the sentences
> you quoted first.
> 
>   If a cursor is open, and the SQL-transaction in which the cursor was
>   opened makes a significant change to SQL-data, then whether that
>   change is visible through that cursor before it is closed is determined
>   as follows:

There seem to be two sections, one dealing with seeing change made by
the same transaction:
        If a cursor is open, and the SQL-transaction in which the cursor        was opened makes a significant change
toSQL-data, then whether        that change is visible through that cursor before it is closed is        determined as
follows:

and then another talking about holdable cursors after the cursor
transaction completes:
        If a holdable cursor is open during an SQL-transaction T and it        is held open for a subsequent
SQL-transaction,then whether any        significant changes made to SQL-data (by T or any subsequent SQL-
transactionin which the cursor is held open) are visible through        that cursor in the subsequent SQL-transaction
beforethat cursor is        closed is determined as follows:
 


--  Bruce Momjian                        |  http://candle.pha.pa.us pgman@candle.pha.pa.us               |  (610)
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