How to use dump blocks vs. bbed to view the SCN when the block contrasts database modifications

Experimental ideas:

The first row of the BYS.A table is updated in the database to find the corresponding file# block#

Then dump this file# block# and view the SCN information

Use bbed dump this file# block# to view SCN information

1. Update a row of the BYS.A table in the database to record the rowid of the row.

19:55:13 bys@ Bys3>select * from A;

B

----------

55

7

3

19:55:15 bys@ bys3>update A set b=0 where b=7;

1 row updated.

19:55:38 bys@ bys3>commit;

Commit complete.

19:55:40 bys@ Bys3>select rowid,b from A; The time of---commit is 19:55:40

ROWID B

------------------ ----------

AAAFOZAAEAAAACSAAA 55

AAAFOZAAEAAAACZAAA 0

AAAFOZAAEAAAACBAAA 3

19:57:15 bys@ Bys3>col object_name for A10

20:01:04 bys@ bys3>select a.rowid,a.object_id,a.file_id,a.block_id,a.row_id,b.object_name,b from (select rowID, Dbms_rowid.rowid_object (ROWID) object_id,dbms_rowid.rowid_relative_fno (ROWID) file_id,dbms_rowid.rowid_block_ Number (ROWID) block_id,dbms_rowid.rowid_row_number (ROWID) row_id,b from BYS.A) a,dba_objects B where a.object_id=                     b.object_id; ---If you use this statement, you only need to modify the name of the table that is marked red, and the field name.

ROWID object_id file_id block_id row_id Object_nam B

------------------ ---------- ---------- ---------- ---------- ---------- ----------

AAAFOZAAEAAAACBAAA 21427 4 0 A 3

AAAFOZAAEAAAACZAAA 21427 4 153 0 A 0

AAAFOZAAEAAAACSAAA 21427 4 146 0 A 55

Through the above statement can query out update a set b=0 where b=7; Modify the block of data is: file#4,block#153

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2. Use dump file#4,block#153 data blocks to view this block of related information---primarily the SCN at the time of modification

20:01:36 bys@ bys3>alter System dump datafile 4 block 153;

System altered.

There are three ways to view the trace file location:

Select value from V$diag_info where name like ' default% ';

sys user execution:oradebug setmypid; Oradebug Tracefile_name

Or use Ls-alt directly in the User_dump_dest directory to find recently generated files

20:05:32 bys@ bys3>col name for A10

20:05:40 bys@ bys3>col value for A50

20:05:49 bys@ Bys3>select * from V$diag_info where name like ' default% ';

inst_id NAME VALUE

---------- ---------- --------------------------------------------------

See more highlights of this column: http://www.bianceng.cnhttp://www.bianceng.cn/database/storage/

1 Default tr/u01/app/oracle/product/11.2.0/dbhome_1/log/diag/r

Ace File DBMS/BYS3/BYS3/TRACE/BYS3_ORA_17341.TRC

The SCN is: scn:0x0000.00197b75---See the following trace file details from the dump information

Convert to SCN for:

20:19:17 bys@ bys3>select to_number (' 197b75 ', ' xxxxxxxxx ') from dual;

To_number (' 197b75 ', ' xxxxxxxxx ')

-------------------------------

1670005

20:19:38 bys@ bys3>select Scn_to_timestamp (1670005) from dual; -Convert the SCN to time to verify that the SCN matches the UPDATE statement submission.

Scn_to_timestamp (1670005)

---------------------------------------------------------------------------

29-NOV-13 07.55.39.000000000 PM

View the details in bys3_ora_17341.trc as follows: = = = Intercept Block block information:

Start dump data blocks Tsn:4 file#:4 minblk 153 maxblk 153

Block dump from cache:

Dump of buffer cache at level 4 for tsn=4 rdba=16777369

BH (0X22BFAD14) file#: 4 rdba:0x01000099 (4/153) class:1 ba:0x22b9e000

Set:3 pool:3 bsz:8192 bsi:0 sflg:1 pwc:0,0

dbwrid:0 obj:21427 objn:21427 Tsn:4 afn:4 hint:f

Hash: [0X22BFBA7C,0X2879BDD8] LRU: [0X22BFAEA4,0X22BFAC10]

CKPTQ: [NULL] FILEQ: [null] OBJQ: [0x22bfaebc,0x25040784] Objaq: [0x22bfbba8,0x22bfb9f0]

St:xcurrent md:null fpin: ' Kdswh01:kdstgr ' tch:6

Flags:block_written_once Redo_since_read

Lrba: [0x0.0.0] LSCN: [0x0.0] HSCN: [0XFFFF.FFFFFFFF] Hsub: [1]

BH (0X22BFB9F8) file#: 4 rdba:0x01000099 (4/153) class:1 ba:0x22bbc000

Set:3 pool:3 bsz:8192 bsi:0 sflg:1 pwc:0,0

dbwrid:0 obj:21427 objn:21427 Tsn:4 afn:4 hint:f

Hash: [0x2879bdd8,0x22bfad98] LRU: [0X22BFACEC,0X217E4BB8]

Lru-flags:hot_buffer

CKPTQ: [NULL] FILEQ: [null] OBJQ: [null] OBJAQ: [NULL]

ST:CR md:null fpin: ' Kdswh01:kdstgr ' tch:0

CR: [SCN:0X0.197B72],[XID:0X0.0.0],[UBA:0X0.0.0],[CLS:0X0.197B72],[SFL:0X0],[LC:0X0.14DA6C]

Flags:only_sequential_access

Block dump from disk:

Buffer Tsn:4 rdba:0x01000099 (4/153)

Scn:0x0000.00197b75 seq:0x02 flg:0x06 tail:0x7b750602

frmt:0x02 chkval:0xe52c Type:0x06=trans Data

Hex dump of Block:st=0, typ_found=1

Dump of memory from 0xb6c41600 to 0xb6c43600

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