Initrans
December 27, 2010 Leave a comment
I was looking at Anand Blog and thought to mention one thing.
I am using 11.2.0.2 Version and here default initrans is 1. Also, the thing i want to mention is when you increase this parameters older blocks are not affected only newly created blocks after this change would be affected.
Taral@Taral1> drop table test1 purge; Table dropped. Taral@Taral1> create table test1(col1 number); Table created. Taral@Taral1> select owner,table_name,INI_TRANS,MAX_TRANS from dba_tables where owner='TARAL'; OWNER TABLE_NAME INI_TRANS MAX_TRANS ------------------------------ ------------------------------ ---------- ---------- TARAL TEST1 1 255 Taral@Taral1> insert into test1 select rownum r from dual connect by level<=10000; 10000 rows created. Taral@Taral1> commit; Commit complete. Taral@Taral1> select segment_name,tablespace_name,header_file, header_block from dba_segments where segment_name='TEST1'; SEGMENT_NAME TABLESPACE_NAME HEADER_FILE HEADER_BLOCK --------------------------------------------------------------------------------- ------------------------------ ----------- ------------ TEST1 USERS 4 522 Taral@Taral1> select SEGMENT_NAME,BLOCK_ID,FILE_ID,TABLESPACE_NAME from dba_extents where SEGMENT_NAME='TEST1'; SEGMENT_NAME BLOCK_ID FILE_ID TABLESPACE_NAME --------------------------------------------------------------------------------- ---------- ---------- ------------------------------ TEST1 520 4 USERS TEST1 528 4 USERS TEST1 536 4 USERS Taral@Taral1> Taral@Taral1> alter system dump datafile 4 block 528; System altered. Block header dump: 0x01000210 Object id on Block? Y seg/obj: 0x127c1 csc: 0x00.d0319 itc: 2 flg: E typ: 1 - DATA brn: 1 bdba: 0x1000208 ver: 0x01 opc: 0 inc: 0 exflg: 0 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0001.002.000002ee 0x00c02ec2.008d.02 --U- 660 fsc 0x0000.000d037d 0x02 0x0000.000.00000000 0x00000000.0000.00 ---- 0 fsc 0x0000.00000000 bdba: 0x01000210 data_block_dump,data header at 0xf298264 Taral@Taral1> alter table test1 initrans 5; Table altered. Taral@Taral1> insert into test1 select rownum r from dual connect by level<=10000; 10000 rows created. Taral@Taral1> commit; Commit complete. Taral@Taral1> select SEGMENT_NAME,BLOCK_ID,FILE_ID,TABLESPACE_NAME from dba_extents where SEGMENT_NAME='TEST1'; SEGMENT_NAME BLOCK_ID FILE_ID TABLESPACE_NAME --------------------------------------------------------------------------------- ---------- ---------- ------------------------------ TEST1 520 4 USERS TEST1 528 4 USERS TEST1 536 4 USERS TEST1 544 4 USERS TEST1 552 4 USERS Taral@Taral1> alter system dump datafile 4 block 544; System altered. Block header dump: 0x01000220 Object id on Block? Y seg/obj: 0x127c2 csc: 0x00.db29d itc: 5 flg: E typ: 1 - DATA brn: 1 bdba: 0x1000218 ver: 0x01 opc: 0 inc: 0 exflg: 0 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x0007.00b.00000306 0x00c00861.009a.05 --U- 654 fsc 0x0000.000db2a5 0x02 0x0000.000.00000000 0x00000000.0000.00 ---- 0 fsc 0x0000.00000000 0x03 0x0000.000.00000000 0x00000000.0000.00 ---- 0 fsc 0x0000.00000000 0x04 0x0000.000.00000000 0x00000000.0000.00 ---- 0 fsc 0x0000.00000000 0x05 0x0000.000.00000000 0x00000000.0000.00 ---- 0 fsc 0x0000.00000000 bdba: 0x01000220 data_block_dump,data header at 0xf2982ac Taral@Taral1> alter system dump datafile 4 block 528; System altered. Block header dump: 0x01000210 Object id on Block? Y seg/obj: 0x127c2 csc: 0x00.d03e4 itc: 2 flg: E typ: 1 - DATA brn: 1 bdba: 0x1000208 ver: 0x01 opc: 0 inc: 0 exflg: 0 Itl Xid Uba Flag Lck Scn/Fsc 0x01 0x000a.015.000002fd 0x00c00112.00a4.0c --U- 660 fsc 0x0000.000d03ec 0x02 0x0000.000.00000000 0x00000000.0000.00 ---- 0 fsc 0x0000.00000000 bdba: 0x01000210 data_block_dump,data header at 0xf298264
Blocks already allocated are not affected but newly created blocks will take new settings.