Oracle Database Discussions

Hi,


I posted this question in the otn sql/ pl/sql forums but could not get any answers.
One user was able to reproduce it but he felt this was a bug.

I am trying to see the amount of redo generated by different insert statements.
I see that for the first insert in the transaction , the redo size is being shown as zero.
The very next insert generates a redo of 2664 bytes (probably for the last two inserts).
All subsequent inserts generate the expected number of redo.


The database I am using is 10.2.0.4

create table temp (
  x int, y char(1000), z date);

Table created.

set autotrace traceonly statistics;

sql> insert into temp values (1, user, sysdate );

1 row created.


Statistics
----------------------------------------------------------
          1  recursive calls
          5  db block gets
          1  consistent gets
          0  physical reads
          0  redo size
        358  bytes sent via SQL*Net to client
        319  bytes received via SQL*Net from client
          3  SQL*Net roundtrips to/from client
          1  sorts (memory)
          0  sorts (disk)
          1  rows processed

--Showing only redo size for subsequent inserts...

sql> insert into temp values (2, user, sysdate);

1 row created.


Statistics
------------
2664  redo size

sql> insert into temp values (3, user, sysdate);

1 row created.


Statistics
----------------------------------------------------------
1300  redo size

sql> insert into temp values (4, user, sysdate);

1 row created.


Statistics
----------------------------------------------------------
1368  redo size

Can someone please explain why this happens?

Thanks,
Rajesh.