Re: Read only transaction problem

From: IANAL_VISTA <IANAL_Vista_at_hotmail.com>
Date: Fri, 03 Jun 2005 14:38:32 GMT
Message-ID: <Xns966A4DBE27EASunnySD@68.6.19.6>

cookie monster <nospam_at_nowhere.com> wrote in news:l5i0a1ladba0ocqabi4crieiev1266k4s8_at_4ax.com:

> Hi,
>
> Using Oracle 9iR2
>
> I have this problem whereby I want to read from 10 tables that have FK
> and the data is always changing. Therefore I use the option SET
> TRANSACTION READ ONLY. Works fine. But now I want to read these 10
> tables and create NEW tables with consistent data (using pl/sql). The
> problem is I can't perform any insert of new data because I get an
> error that the transaction is read only.
>
> Is there any way around this problem? I just want to create a copy of
> these 10 tables with consisitent data. Any ideas??
>

Oracle ALWAYS guarentees a read consistent view of the data!

RTFM - Data Concurrency and Consistency Overview

http://downloadwest.
oracle.com/docs/cd/B10501_01/server.920/a96524/c01_02intro.htm#44609

Read Consistency

Read consistency, as supported by Oracle, does the following:

Guarantees that the set of data seen by a statement is consistent with respect to a single point in time and does not change during statement execution (statement-level read consistency)
Ensures that readers of database data do not wait for writers or other readers of the same data
Ensures that writers of database data do not wait for readers of the same data
Ensures that writers only wait for other writers if they attempt to update identical rows in concurrent transactions

The simplest way to think of Oracle's implementation of read consistency is to imagine each user operating a private copy of the database, hence the multiversion consistency model. Received on Fri Jun 03 2005 - 09:38:32 CDT