Oracle FAQ Your Portal to the Oracle Knowledge Grid
HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US
 

Home -> Community -> Mailing Lists -> Oracle-L -> Redo Logfile content- (A)SQL Statements OR (B)Modified Data Block OR (C)BOTH

Redo Logfile content- (A)SQL Statements OR (B)Modified Data Block OR (C)BOTH

From: <Saminathan_Seerangan_at_i2.com>
Date: Sun, 04 May 2003 23:06:45 -0800
Message-ID: <F001.0058F278.20030504230645@fatcity.com>


Dear All DBAs,

I've a very basic doubt. I got size of 300MB archive redo logfile for "one create table" statement.

What do we have in Redo Log File?
(A)SQL Statements OR (B)Modified Data Block OR (C)
BOTH. Kindly look at case study below.

Oracle 9iR2 Windows NT ARCHIVE LOG Mode


Tablespace info:-

Name                                             : EXAMPLE
Datafile Name                            : example01.dbf
Extent_management                : LOCAL
Allocation_type                          : SYSTEM
Segment_Space_Management: AUTO
Default Tablespace of            : HR

1)Original example01.dbf datafile size 500MB;

2)create table HR.T2 pctfree 99 pctused 1 as select * from dba_objects;

                 (used PCTFREE 99 to increase the table size by
absorbing more number of blocks)

3)

SQL> select count(*) from t2;

  COUNT(*)


     38085

SQL> select bytes,blocks,extents from dba_segments where segment_name='T2' and owner='HR';

     BYTES BLOCKS EXTENTS
---------- ---------- ----------
 318767104 38912 109

4)After table creation, example01.dbf datafile size becomes 800MB;

                 (datafile size got increased because of Table T2
creation)

Q1) How much archive will be generated between step(1) and step(4).
(Assume that this is the only activity happened in the
DB)

Here 60 number of 5MB archive files got
generated(close to 300 MB).

My question about Redo log file-->
(A) Does it have actual modified blocks? OR

OR

(B) Does it have just the stament which has been used
to modify the datablocks?

                 (Using LogMiner I see only statements)
OR

(C) BOTH

-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.net
-- 
Author: 
  INET: Saminathan_Seerangan_at_i2.com

Fat City Network Services    -- 858-538-5051 http://www.fatcity.com
San Diego, California        -- Mailing list and web hosting services
---------------------------------------------------------------------
To REMOVE yourself from this mailing list, send an E-Mail message
to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in
the message BODY, include a line containing: UNSUB ORACLE-L

(or the name of mailing list you want to be removed from). You may
also send the HELP command for other information (like subscribing).
Received on Mon May 05 2003 - 02:06:45 CDT

Original text of this message

HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US