Hi,
Oracle does not save the data, in mid transaction, in the sense of a commit.
It keeps the association of the memory address related to the error free 
changes to the transaction and allows you – the developer to capture the error 
on  that single incorrect change, and then continue with the subsequent sql 
statements that are part of that long transaction.
While in that state, the changes pertaining to that transaction are not written 
to any logs and are not written to file, you can still roll back the entire 
transaction.
Only when a commit occurs, does the transaction get written to SGA, archiving, 
file etc…

With Postgres that is not the case, if the 50th sql statement in a long 
transaction incurs an error, the whole transaction is rolled back for you 
automatically, you the developer have no say in that unless you bracket each 
statement with a savepoint creation and destruction, just to be able to capture 
the potential error that may arise on that 50th sql statement.

Sincerely,
Kasia
From: pgsql-admin-ow...@postgresql.org 
[mailto:pgsql-admin-ow...@postgresql.org] On Behalf Of Bèrto ëd Sèra
Sent: Wednesday, November 30, 2011 12:49 AM
To: pgsql-admin@postgresql.org
Subject: Re: [ADMIN] transaction error handling

On 29 November 2011 21:34, Rob Richardson 
<rdrichard...@rad-con.com<mailto:rdrichard...@rad-con.com>> wrote:
If Oracle saves half of the data  between the beginning and ending of the 
transaction, doesn't that defeat the purpose of the transaction?

It sure enough kills Atomicity. I can see a use for this on importing data from 
external sources that may violate existing unique keys, so illegal inserts are 
ignored, but you still are left without any knowledge of what rows where 
silently dropped. Since when is Oracle doing this, FMI? (It's been a long while 
since I used it for anything serious)

Bèrto

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