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

From Hiroshi Inoue
Subject Re: updateable cursors & visibility
Date
Msg-id EKEJJICOHDIEMGPNIFIJIEDLLBAA.Inoue@tpf.co.jp
Whole thread Raw
In response to Re: updateable cursors & visibility  (Bruce Momjian <pgman@candle.pha.pa.us>)
Responses Re: updateable cursors & visibility
List pgsql-hackers
> -----Original Message-----
> From: Bruce Momjian [mailto:pgman@candle.pha.pa.us]
> 
> Hiroshi Inoue wrote:
> > > > I don't understand what you two are discussing.
> > > > What's is SENSITIVE, INSENSITIVE or ASESNSITIVE ?
> > > 
> > > In SQL99 standard, I see:
> > > 
> > >          -  If the cursor is insensitive, then significant 
> changes are not
> > >             visible.
> > > 
> > >          -  If the cursor is sensitive, then significant changes are
> > >             visible.
> > > 
> > >          -  If the cursor is asensitive, then the visibility 
> of significant
> > >             changes is implementation-dependent.
> > 
> > While a cursor is open, another application inserted a
> > row which satisfies the condition to be contained in
> > the cursor and committed. Then
> > If the cursor is SENSITIVE, must it see the row ?
> 
> Right.
> 
> > If the cursor is INSENSITIVE, it mustn't see the row ?
> 
> Right.

If so, isn't the difference between SENSITIVE and INSENSITIVE extreme ?
Why do you or Peter refer to ASENSITIVE little ?
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,
thenwhether that change is visible through that cursor before it is closed is determined as follows:
 

regards,
Hiroshi Inoue 



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