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asanam.85@gmail.com 03-28-2007 08:38 AM

transaction
 
when we dont commit in oracle wat happens whether it wil fetch
previous record


usenetuser@hotmail.co.uk 03-28-2007 09:25 AM

Re: transaction
 
On Mar 28, 9:38 am, "asanam...@gmail.com" <asanam...@gmail.com> wrote:
> when we dont commit in oracle wat happens whether it wil fetch
> previous record


This is comp.lang.*java*.programmer. You may be better off asking
this OT question in an Oracle newsgroup.

However, if by fetch you mean SELECT after a modification using UPDATE/
DELETE/INSERT, but prior to COMMIT, the subsequent SELECT will return
the modified record *as long as you are within the same session/
transaction*. All other sessions/transactions will show the
unmodified records (or block) until the COMMIT occurs.


Lew 03-28-2007 11:55 AM

Re: transaction
 
usenetuser@hotmail.co.uk wrote:
> On Mar 28, 9:38 am, "asanam...@gmail.com" <asanam...@gmail.com> wrote:
>> when we dont commit in oracle wat happens whether it wil fetch
>> previous record

>
> This is comp.lang.*java*.programmer. You may be better off asking
> this OT question in an Oracle newsgroup.
>
> However, if by fetch you mean SELECT after a modification using UPDATE/
> DELETE/INSERT, but prior to COMMIT, the subsequent SELECT will return
> the modified record *as long as you are within the same session/
> transaction*. All other sessions/transactions will show the
> unmodified records (or block) until the COMMIT occurs.


It can actually get more complicated depending on how concurrent accesses
interleave with COMMITs. The bottom line is the same though: until transaction
"A" commits then transaction "B" cannot (reliably) see the results.

The complications arise from the interactions between, say, DELETEs and
INSERTs, and from effects of the four different levels of transaction isolation.

-- Lew


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