Hi List, I was showing another DBA how delayed block clean out mechanism works when I found this.... Oracle 8.0.6.3.0 delayed_logging_block_cleanouts=TRUE (default) created a simple table, inserted some records, commited. Then performed a clean out (analyzed the table), updated all rows and commited again Table size around 7500 blocks Buffer cache size 64000 blocks SQL> update test_dbc set first=first+1; 350000 rows updated. SQL> commit; Commit complete. (blockdump) Block header after the update and the commit. Block header dump: rdba: 0x00419809 Object id on Block? Y seg/obj: 0x16a66 csc: 0x698.b1acfb7c itc: 1 flg: - typ: 1 - DATA fsl: 0 fnx: 0x0 ver: 0x01 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0002.05f.0001454f 0x00822873.0b8f.29 ---- 48 fsc 0x0000.00000000 (Up to here everything was looking fine.....) Then I ran a simple query from another session: SQL> select sum(first) from test_dbc; SUM(FIRST) ---------- 6.125E+10 and I got: select a.sid, b.name, a.value from v$sesstat a , v$statname b where a.STATISTIC#=b.STATISTIC# and (b.name like '%clean%' or b.name like '%redo%') and a.sid=&sid and a.value != 0 order by 2 SID NAME VALUE --------- ---------------------------------------------------------------- --------- 9 cleanouts only - consistent read gets 872 9 immediate (CR) block cleanout applications 872 9 redo entries 872 9 redo size 52320 So I took another blockdump (Same blockdump taken before) after the query execution: Block header dump: rdba: 0x00419809 Object id on Block? Y seg/obj: 0x16a66 csc: 0x698.b1acfbfc itc: 1 flg: - typ: 1 - DATA fsl: 0 fnx: 0x0 ver: 0x01 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0002.05f.0001454f 0x00822873.0b8f.29 C--- 0 scn 0x0698.b1acfbcc why did this block get cleaned out? . I just executed a query not a DML command. I then checked every table block and all of them got cleaned out by the query shown above. AFAIK in Oracle 7 and Oracle 8 version after executing a query this block should not have been cleaned out unless delayed_logging_block_cleanouts=FALSE (I have also tested this in an Oracle 7 instance, and I got the same result) Please shed some light on this. Thanks Diego. ---------------------------------------------------------------- Please see the official ORACLE-L FAQ: http://www.orafaq.com ---------------------------------------------------------------- To unsubscribe send email to: oracle-l-request@xxxxxxxxxxxxx put 'unsubscribe' in the subject line. -- Archives are at //www.freelists.org/archives/oracle-l/ FAQ is at //www.freelists.org/help/fom-serve/cache/1.html -----------------------------------------------------------------