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

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  INET: Saminathan_Seerangan_at_i2.com

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Received on Mon May 05 2003 - 02:06:45 CDT