The document discusses the capabilities and usage of Oracle's Flashback technology, which allows users to retrieve historical data and undo changes to the database. It emphasizes the importance of read consistency, various flashback queries, and provides SQL examples demonstrating how to implement these features. The text serves as a guide for database administrators on effectively using Flashback functionality for data recovery and versioning.

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Copyright © 2019 Oracle and/or its affiliates.
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Connor McDonald
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Stuff
youtube bit.ly/youtube-connor
blog bit.ly/blog-connor
twitter bit.ly/twitter-connor
400+ posts mainly on database & development
250 technical videos, new uploads every week
rants and raves on tech and the world :-)
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etc...
facebook bit.ly/facebook-connor
linkedin bit.ly/linkedin-connor
instagram bit.ly/instagram-connor
slideshare bit.ly/slideshare-connor
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9 9https://asktom.oracle.com
10 10https://asktom.oracle.com/officehours
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Flashback - not just for DBAs
Database Advocate
Connor McDonald
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flashback
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several different technologies
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flashback query
flashback table
flashback drop
flashback database
flashback transaction
flashback data archive
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flashback query
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controversy
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you have always
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been using flashback query
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revision
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SQL> update EMP
2 set SAL = SAL * 1.10
3 /
14 rows updated.
SQL> rollback;
Rollback complete.
how ?
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we remember stuff
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SQL> update EMP
2 set SAL = SAL * 1.10
3 where ename = 'SMITH'
undo header
smith $1,0001
block 2754
jones $9002
brown $1,5003
wells $2,0004
wilson $1,0005
block 2754, row 1,
sal $1000
uba 5 5
$1,100
uba 5.1
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SQL> rollback;
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SQL> rollback;
undo header
smith $1,0001
block 2754
jones $9002
brown $1,5003
wells $2,0004
wilson $1,0005
block 2754, row 1,
sal $1000
uba 5
5
$1,100
uba 5.1
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we can use this stuff for queries!
(Oracle version 4)
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read consistency
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select * from emp
where hiredate > '01/01/2004'
update emp set ename = 'SUE'
where ename = 'JOHN';
Block 3217
"I need block 3217…
… as it was at 9:00"
9:00
9:03
9:05
session 1 session 2
...and time = scn
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system change number
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Session 1
Request
Block 3217,
SCN 4567192
Block 3217,
SCN 4567234
"SUE"
Block 3217,
SCN 4567003,
change SUE => JOHN
undo segment block(s)
No good..too new
take a copy of the block
Locate
apply undo
Block 3217,
SCN 4567234
" SUE"
Block 3217,
SCN 4567234
" SUE"
Block 3217,
SCN 4567003
" JOHN"
Block 3217,
SCN 4567003
"JOHN"
Session 2
update emp
set ename = 'SUE'
where ename = 'JOHN'
commit;
Done !
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stress: vast simplification
in-memory undo
throwaway undo
slots
expiry
wrap#
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every query = locked at a SCN
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go back further....
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flashback query = choose the SCN
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v9
circa 2001
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SQL> select * from DEPT;
DEPTNO DNAME LOC
---------- -------------- -------------
10 UNKNOWN NEW YORK
20 UNKNOWN DALLAS
30 UNKNOWN CHICAGO
40 UNKNOWN BOSTON
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SQL> select * from DEPT AS OF SCN 995401;
DEPTNO DNAME LOC
---------- -------------- -------------
10 ACCOUNTING NEW YORK
20 RESEARCH DALLAS
30 SALES CHICAGO
40 OPERATIONS BOSTON
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less geeky
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SQL> select * from DEPT
2 AS OF TIMESTAMP systimestamp -
3 interval '20:00' minute to second;
DEPTNO DNAME LOC
---------- -------------- -------------
10 ACCOUNTING NEW YORK
20 RESEARCH DALLAS
30 SALES CHICAGO
40 OPERATIONS BOSTON
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SQL> select TIMESTAMP_TO_SCN(systimestamp)
2 from DUAL;
TIMESTAMP_TO_SCN(SYSTIMESTAMP)
------------------------------
998332
SQL> select SCN_TO_TIMESTAMP(998314) from DUAL;
SCN_TO_TIMESTAMP(998314)
-----------------------------------------------
16-SEP-19 09.12.48.000000000 PM
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3 seconds
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SQL> select scn_to_timestamp(2409511-rownum)
2 from dual
3 connect by level <= 50;
SCN_TO_TIMESTAMP(2409511-ROWNUM)
---------------------------------------------
16-SEP-19 05.47.47.000000000 PM
16-SEP-19 05.47.47.000000000 PM
16-SEP-19 05.47.44.000000000 PM
16-SEP-19 05.47.41.000000000 PM
16-SEP-19 05.47.37.000000000 PM
16-SEP-19 05.47.34.000000000 PM
16-SEP-19 05.47.31.000000000 PM
16-SEP-19 05.47.28.000000000 PM
16-SEP-19 05.47.25.000000000 PM
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use in "normal" queries
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SQL> select e.empno, e.ename, d.dname
2 from emp e,
3 dept AS OF TIMESTAMP '16-SEP-19' d
3 where d.deptno = e.deptno;
EMPNO ENAME DNAME
---------- ---------- --------------
7782 CLARK "PREVIOUS NAME"
7839 KING "PREVIOUS NAME"
7934 MILLER "PREVIOUS NAME"
7566 JONES RESEARCH
7902 FORD RESEARCH
7876 ADAMS RESEARCH
7369 SMITH RESEARCH
7788 SCOTT RESEARCH
"What is in it for me?"
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1) unit testing
before vs after
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SQL> select case
2 when d1.deptno is null then 'DELETE'
3 when d2.deptno is null then 'INSERT'
4 end action,
5 d1.deptno, d2.deptno, d1.dname, d1.loc
6 from DEPT d1 full outer join
7 DEPT AS OF TIMESTAMP '16-SEP-19 11.51.02 PM' d2
8 on d1.deptno = d2.deptno;
ACTION DEPTNO DEPTNO DNAME LOC
------ ---------- ---------- -------------- ----------
10 10 ACCOUNTING NEW YORK
20 20 RESEARCH DALLAS
30 30 SALES CHICAGO
DELETE 40
INSERT 50 MARKETING PERTH
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2) not just your data
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SQL> drop procedure debug_msg;
Procedure dropped.
SQL> connect / as sysdba
Connected.
SQL> select text
2 from dba_source
3 as of timestamp systimestamp - interval '5' minute
4 where name='DEBUG_MSG' order by line;
TEXT
---------------------------------------------------------------------
procedure debug_msg(m varchar2) is
begin
dbms_output.put_line(m);
dbms_application_info.set_client_info(m);
end;
5 rows selected.
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3) functionality diagnosis
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SQL> select * from DEPT;
DEPTNO DNAME LOC
---------- -------------- -------------
10 UNKNOWN NEW YORK
SQL> select * from DEPT
2 as of TIMESTAMP SYSTIMESTAMP -
3 INTERVAL '20:00' MINUTE TO SECOND;
DEPTNO DNAME LOC
---------- -------------- -------------
10 ACCOUNTING NEW YORK
1 change ?
10 changes ?
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flashback row versions
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SQL> SELECT deptno, dname
2 FROM dept
3 VERSIONS BETWEEN
4 TIMESTAMP SYSTIMESTAMP –
5 INTERVAL '20:00' MINUTE TO SECOND
6 AND SYSTIMESTAMP
7 WHERE deptno = 10;
DEPTNO DNAME
---------- --------------
10 ACCOUNTING
10 MONEY GRABBERS
10 FINANCE
10 BEAN COUNTERS
10 UNKNOWN
1 row
5 versions
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versions_starttime
versions_startscn
versions_endtime
versions_endscn
versions_xid
versions_operation
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SQL> SELECT deptno, dname,
2 VERSIONS_STARTTIME
3 ,VERSIONS_XID
4 ,VERSIONS_OPERATION
5 FROM dept
6 VERSIONS BETWEEN TIMESTAMP
7 SYSTIMESTAMP - INTERVAL '20:00' MINUTE TO SECOND
8 AND SYSTIMESTAMP
9 WHERE deptno = 10;
DEPTNO DNAME VERSIONS_STARTTIME VERSIONS_XID V
--------- -------------- ---------------------- ---------------- -
10 UNKNOWN 16-SEP-19 11.53.45 PM 0200100060040000 U
10 MONEY GRABBERS 16-SEP-19 11.53.36 PM 0600050065040000 U
10 FINANCE 16-SEP-19 11.53.24 PM 09000D001D050000 U
10 BEAN COUNTERS 16-SEP-19 11.53.12 PM 01001A00EA030000 U
10 ACCOUNTING
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get the lot ...
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SQL> SELECT deptno, dname,
2 VERSIONS_STARTTIME
3 ,VERSIONS_XID
4 ,VERSIONS_OPERATION
5 FROM dept VERSIONS BETWEEN SCN MINVALUE AND MAXVALUE;
DEPTNO DNAME VERSIONS_STARTTIME VERSIONS_XID V
---------- ----------- ------------------------ ---------------- -
50 UNKNOWN 16-SEP-19 11.08.15 PM 04000700EA030000 U
30 UNKNOWN 16-SEP-19 11.08.15 PM 04000700EA030000 U
20 NERDS 16-SEP-19 11.07.57 PM 090016001D050000 U
20 R&D 16-SEP-19 11.07.48 PM 05000B0074040000 U
...
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it might be expensive
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grant flashback to ...
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session level
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dbms_flashback.enable_at_time(systimestamp-1/24);
select * from emp;
select * from dept;
etc etc
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just how far ?
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undo_retention
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SQL> show parameter undo_retention
NAME TYPE VALUE
------------------------------ ----------- --------
undo_retention integer 900
~
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SQL> desc v$undostat
Name Null? Type
----------------------------- -------- -----------
BEGIN_TIME DATE
END_TIME DATE
...
...
TUNED_UNDORETENTION NUMBER
CON_ID NUMBER
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much much further
flashback data archive
flashback transaction
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SQL> SELECT deptno, dname,
2 VERSIONS_STARTTIME
3 ,VERSIONS_XID
4 ,VERSIONS_OPERATION
5 FROM dept VERSIONS BETWEEN SCN MINVALUE AND MAXVALUE;
DEPTNO DNAME VERSIONS_STARTTIME VERSIONS_XID V
--------- --------- ----------------------- ---------------- -
50 UNKNOWN 16-SEP-19 11.08.15 PM 04000700EA030000 U
30 UNKNOWN 16-SEP-19 11.08.15 PM 04000700EA030000 U
20 NERDS 16-SEP-19 11.07.57 PM 090016001D050000 U
20 R&D 16-SEP-19 11.07.48 PM 05000B0074040000 U
...
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XID ?
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SQL> desc V$TRANSACTION
Name Null? Type
----------------------------- -------- -------
XIDUSN NUMBER
XIDSLOT NUMBER
XIDSQN NUMBER
...
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SQL> select
2 XIDUSN, XIDSLOT, XIDSQN
3 from v$transaction
XIDUSN XIDSLOT XIDSQN
---------- ---------- ----------
1 31 674
SQL> select versions_xid from ...
VERSIONS_XID
-------------------
01 001F 00A202 0000
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SQL> desc FLASHBACK_TRANSACTION_QUERY
Name Null? Type
----------------------- -------- --------------
XID RAW(8)
START_SCN NUMBER
START_TIMESTAMP DATE
COMMIT_SCN NUMBER
COMMIT_TIMESTAMP DATE
LOGON_USER VARCHAR2(30)
UNDO_CHANGE# NUMBER
OPERATION VARCHAR2(32)
TABLE_NAME VARCHAR2(256)
TABLE_OWNER VARCHAR2(32)
ROW_ID VARCHAR2(19)
UNDO_SQL VARCHAR2(4000)
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SQL> update dept
2 set DNAME = 'FINANCE'
2 where deptno = 10;
1 row updated.
SQL> select xid, undo_sql
2 from flashback_transaction_query
3 where xid = hextoraw('09000d001d050000');
XID UNDO_SQL
---------------- ------------------------------------
09000D001D050000 update "SCOTT"."DEPT"
set "DNAME" = 'BEAN COUNTERS'
where ROWID = 'AAAQ+hAAEAAAAAOAAA';
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be careful
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SQL> select text from dba_views
2 where view_name
3 = 'FLASHBACK_TRANSACTION_QUERY';
TEXT
------------------------------------------------
select xid, start_scn, start_timestamp,
decode(commit_scn,
0, commit_scn,
281474976710655, NULL, commit_scn)
commit_scn, commit_timestamp,
logon_user, undo_change#, operation,
table_name, table_owner,
row_id, undo_sql
from SYS.X$KTUQQRY
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do not query without predicates ...
SQL> select xid, undo_sql
2 from flashback_transaction_query
3 where xid = hextoraw('09000d001d050000');
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do not forget hextoraw
SQL> select xid, undo_sql
2 from flashback_transaction_query
3 where xid = hextoraw('09000d001d050000');
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SQL> select xid, undo_sql
2 from flashback_transaction_query
3 where xid = hextoraw('09000d001d050000');
-----------------------------------------------------
| Id | Operation | Name |
-----------------------------------------------------
| 0 | SELECT STATEMENT | |
|* 1 | FIXED TABLE FIXED INDEX| X$KTUQQRY (ind:1) |
-----------------------------------------------------
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SQL> select xid, undo_sql
2 from flashback_transaction_query
3 where xid = '09000d001d050000';
--------------------------------------
| Id | Operation | Name |
--------------------------------------
| 0 | SELECT STATEMENT | |
| 1 | FIXED TABLE FULL| X$KTUQQRY |
--------------------------------------
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UNDO_SQL
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rollback committed transaction
"What is in it for me?"
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1) accidents
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three words
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delete
uh-oh...
commit
9797
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flashback transaction
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SQL> delete from DEPT where DEPTNO = 10;
1 row deleted.
SQL> commit;
Commit complete.
SQL> SELECT VERSIONS_XID
2 FROM dept
3 VERSIONS BETWEEN SCN MINVALUE AND MAXVALUE;
VERSIONS_XID
----------------
080017006C040000
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SQL> BEGIN
2 DBMS_FLASHBACK.TRANSACTION_BACKOUT(
3 numtxns=> 1,
4 xids => sys.xid_array('080017006C040000')
5 );
6 END;
7 /
BEGIN
*
ERROR at line 1:
ORA-55510: Mining could not start
ORA-06512: at "SYS.DBMS_FLASHBACK", line 37
ORA-06512: at "SYS.DBMS_FLASHBACK", line 70
ORA-06512: at line 2
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SQL> ALTER DATABASE ADD
2 SUPPLEMENTAL LOG DATA
3 (PRIMARY KEY) COLUMNS;
Database altered.
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SQL> delete from DEPT where DEPTNO = 10;
1 row deleted.
SQL> commit;
Commit complete.
SQL> SELECT VERSIONS_XID
2 FROM dept
3 VERSIONS BETWEEN SCN MINVALUE AND MAXVALUE;
VERSIONS_XID
----------------
080017006C040000
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SQL> BEGIN
2 DBMS_FLASHBACK.TRANSACTION_BACKOUT(
3 numtxns => 1,
4 xids => sys.xid_array('080017006C040000')
5 );
6 END;
7 /
SQL> select * from DEPT;
DEPTNO DNAME LOC
---------- -------------- ----------
20 RESEARCH DALLAS
30 SALES CHICAGO
50 MARKETING PERTH
40 HR US?
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KEEP CALM
AND
DON'T PANIC
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SQL> SELECT COMPENSATING_XID
2 FROM DBA_FLASHBACK_TXN_STATE
3 WHERE xid = '080017006C040000';
COMPENSATING_XID
----------------
03001C0072040000
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SQL> SELECT xid_report
2 FROM DBA_FLASHBACK_TXN_REPORT
3 WHERE compensating_xid = '03001C0072040000';
XID_REPORT
--------------------------------------------------------
<COMP_XID_REPORT XID="03001C0072040000">
<TRANSACTION XID="080017006C040000">
<UNDO_SQL>
<USQL exec="yes">
insert into "SCOTT"."DEPT"("DEPTNO","DNAME","LOC")
values ('10','ACCOUNTING','NEW YORK')
</USQL>
</UNDO_SQL>
</TRANSACTION>
<EXECUTED_UNDO_SQL>
<EXEC_USQL>
insert into "SCOTT"."DEPT"("DEPTNO","DNAME","LOC")
values ('10','ACCOUNTING','NEW YORK')
</EXEC_USQL>
</EXECUTED_UNDO_SQL>
</COMP_XID_REPORT>
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SQL> commit;
Commit complete.
SQL> select * from dept;
DEPTNO DNAME LOC
---------- -------------- ----------
20 RESEARCH DALLAS
30 SALES CHICAGO
50 MARKETING PERTH
40 HR US
10 ACCOUNTING NEW YORK
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2) unit tests
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run test ... capture XID
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commit... validate... undo transaction
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flashback drop
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delete
uh-oh...
commit
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flashback transaction
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three words
two
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drop
uh-oh...
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SQL> desc EMP
ERROR:
ORA-04043: object EMP does not exist
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"undrop"
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not cool enough
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flashback table to before drop
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SQL> desc USER_RECYCLEBIN
Name Null? Type
----------------------------- -------- ----------------
OBJECT_NAME NOT NULL VARCHAR2(30)
ORIGINAL_NAME VARCHAR2(32)
OPERATION VARCHAR2(9)
TYPE VARCHAR2(25)
TS_NAME VARCHAR2(30)
CREATETIME VARCHAR2(19)
DROPTIME VARCHAR2(19)
DROPSCN NUMBER
PARTITION_NAME VARCHAR2(32)
CAN_UNDROP VARCHAR2(3)
CAN_PURGE VARCHAR2(3)
RELATED NOT NULL NUMBER
BASE_OBJECT NOT NULL NUMBER
PURGE_OBJECT NOT NULL NUMBER
SPACE NUMBER
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SQL> select OBJECT_NAME, ORIGINAL_NAME,
2 CAN_UNDROP, CAN_PURGE
3 from USER_RECYCLEBIN;
OBJECT_NAME ORIGINAL_NAME CAN CAN
-------------------------------- --------------- --- ---
BIN$CmYCdNcITL6hp9l266nskA==$0 PK_EMP NO YES
BIN$b/W75+c/Q/CeFMBIK7cXfw==$0 EMP YES YES
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SQL> show RECYCLEBIN
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SQL> flashback table EMP to before drop;
Flashback complete.
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SQL> flashback table EMP to before drop
2 rename to OLD_EMP;
Flashback complete.
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how long ?
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SQL> PURGE RECYCLEBIN;
SQL> PURGE DBA_RECYCLEBIN;
SQL> PURGE TABLE emp;
SQL> PURGE TABLE "BIN$xyWe0+q+SniItJ0pn/u54A==$0";
SQL> PURGE TABLESPACE user1;
SQL> PURGE TABLESPACE user1 USER fred;
SQL> PURGE INDEX "BIN$FTX34MN88J7==$0";
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no untruncate
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flashback table
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139
flashback table
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SQL> FLASHBACK TABLE DEPT
2 TO TIMESTAMP TIMESTAMP '2019-09-16 12:05:00'
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"undrop"
"What is in it for me?"
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repeatable tests without cleanup scripts
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test ... commit ... flashback to start point
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deletes modified rows since SCN
inserts fresh rows as of SCN
... busy
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single transaction
... multiple tables allowed
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tables locked
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R.I must still be valid
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154
most DDL is a flashback boundary
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SQL> flashback table DEPT to scn ...;
ORA-01466: unable to read data - table definition has changed
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each release gets better
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SQL> alter table DEPT add column XXX date;
SQL> flashback table DEPT to scn ...;
SQL> desc DEPT
Name Null? Type
-------------------------- -------- --------------
DEPTNO NUMBER(2)
DNAME VARCHAR2(14)
LOC VARCHAR2(13)
XXX DATE
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flashback database
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flashback database
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Copyright © 2018, Oracle and/or its affiliates. All rights reserved. |
AUTHORISED
DATABASE
ADMINSTRATORS
ONLY !
164
SQL> alter database flashback on;
Database altered.
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data
changes
"new" blocks
to disk
changes
to disk
"old" blocks
to disk
redo fbdadbwr
166
SQL> FLASHBACK DATABASE TO '2:05PM'
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SQL> create restore point OK_SO_FAR;
...
SQL> flashback database to
2 restore point OK_SO_FAR;
168
what does it cost ?
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SQL> desc V$FLASHBACK_DATABASE_STAT
Name Null? Type
----------------------------- -------- ---------
BEGIN_TIME DATE
END_TIME DATE
FLASHBACK_DATA NUMBER
DB_DATA NUMBER
REDO_DATA NUMBER
ESTIMATED_FLASHBACK_SIZE NUMBER
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a good compromise
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guaranteed restore points
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flashback logging "optional"
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"What is in it for me?"
177
1) safer deployment
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scenario: "My New Application"
179
9:00
9:40
9:45 SQL> FLASHBACK DATABASE...
SQL> alter table ACCOUNTS add ...
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2) repeatable end to end testing
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flashback pluggable database
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3) production data for developers
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aka "hidden" flashback database
185
5:00am
11:30pm
standby recovery
convert to snapshot
revert to physical
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flashback data archive
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less flashback, more archive
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SQL> CREATE FLASHBACK ARCHIVE longterm
2 TABLESPACE space_for_archive
3 RETENTION 1 YEAR;
Flashback archive created.
194
SQL> ALTER TABLE EMP FLASHBACK ARCHIVE LONGTERM;
Table altered.
[lots of DML on EMP]
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SQL> select * from EMP;
--------------------------------------------------
| Id | Operation | Name | Rows | Bytes |
--------------------------------------------------
| 0 | SELECT STATEMENT | | 14 | 518 |
| 1 | TABLE ACCESS FULL| EMP | 14 | 518 |
--------------------------------------------------
196
SQL> select * from EMP
2 AS OF TIMESTAMP SYSDATE-1/24;
--------------------------------------------------
| Id | Operation | Name | Rows | Bytes |
--------------------------------------------------
| 0 | SELECT STATEMENT | | 14 | 518 |
| 1 | TABLE ACCESS FULL| EMP | 14 | 518 |
--------------------------------------------------
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3 days later...
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SQL> select * from EMP
2 AS OF TIMESTAMP SYSDATE-3;
-----------------------------------------------------------------
| Id | Operation | Name | Rows |
-----------------------------------------------------------------
| 0 | SELECT STATEMENT | | 446 |
| 1 | VIEW | | 446 |
| 2 | UNION-ALL | | |
|* 3 | FILTER | | |
| 4 | PARTITION RANGE ITERATOR| | 445 |
|* 5 | TABLE ACCESS FULL | SYS_FBA_HIST_69539 | 445 |
|* 6 | FILTER | | |
|* 7 | HASH JOIN OUTER | | 1 |
|* 8 | TABLE ACCESS FULL | EMP | 1 |
|* 9 | TABLE ACCESS FULL | SYS_FBA_TCRV_69539 | 14 |
------------------------------------------------------------------
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85. 9/19/2019
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SQL> select table_name
2 from user_tables
3 /
TABLE_NAME
---------------------------
SYS_FBA_HIST_71036
SYS_FBA_TCRV_71036
SYS_FBA_DDL_COLMAP_71036
EMP
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SQL> select dbms_metadata.get_ddl(
2 'TABLE',
3 'SYS_FBA_TCRV_71036') from dual;
DDL
------------------------------------
CREATE TABLE "SCOTT"."SYS_FBA_TCRV_71036"
( "RID" VARCHAR2(4000),
"STARTSCN" NUMBER,
"ENDSCN" NUMBER,
"XID" RAW(8),
"OP" VARCHAR2(1)
)
SEGMENT CREATION IMMEDIATE
TABLESPACE "SPACE_FOR_ARCHIVE"
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86. 9/19/2019
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SQL> select dbms_metadata.get_ddl(
2 'TABLE',
3 'SYS_FBA_HIST_71036') from dual;
DDL
------------------------------------------
CREATE TABLE "SCOTT"."SYS_FBA_HIST_71036"
( "RID" VARCHAR2(4000),
"STARTSCN" NUMBER,
"ENDSCN" NUMBER,
"XID" RAW(8),
"OPERATION" VARCHAR2(1),
"EMPNO" NUMBER(4,0), "ENAME" VARCHAR2(10),
"JOB" VARCHAR2(9), "MGR" NUMBER(4,0),
"HIREDATE" DATE, "SAL" NUMBER(7,2),
"COMM" NUMBER(7,2), "DEPTNO" NUMBER(2,0)
) COMPRESS FOR OLTP
TABLESPACE "SPACE_FOR_ARCHIVE"
PARTITION BY RANGE ("ENDSCN")
( PARTITION "HIGH_PART" VALUES LESS THAN (MAXVALUE) )
"What is in it for me?"
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87. 9/19/2019
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"I dont care what EMP looked like in June"
206206
why talk about it ?
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88. 9/19/2019
88
207207
SQL> select * from EMP AS OF "JUNE";
SQL> select * from EMP AS OF "MARCH";
SQL> select * from EMP AS OF "2pm Wednesday";
SQL> select * from EMP AS OF etc etc etc
208208
every historical version...
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89. 9/19/2019
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209209
... of every row
210210
sound familiar ?
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90. 9/19/2019
90
211211
audit history
212212
we've all done it
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91. 9/19/2019
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213213
SQL> desc T
Name Null? Type
------------------------ -------- -------------
OWNER NOT NULL VARCHAR2(30)
OBJECT_NAME NOT NULL VARCHAR2(30)
SQL> desc T_AUDIT
Name Null? Type
------------------------ -------- --------------
AUDIT_DATE DATE
AUDIT_ACTION CHAR(1)
OWNER NOT NULL VARCHAR2(30)
OBJECT_NAME NOT NULL VARCHAR2(30)
214214
SQL> create or replace
2 trigger AUDIT_TRG
3 after insert or update or delete on T
4 for each row
5 declare
6 v_action varchar2(1) :=
7 case when updating then 'U'
8 when deleting then 'D' else 'I' end;
9 begin
10 if updating or inserting then
11 insert into T_AUDIT
12 values (sysdate
13 ,v_action
14 ,:new.owner
15 ,:new.object_name);
16 else
17 insert into T_AUDIT
18 values (sysdate
19 ,v_action
20 ,:old.owner
21 ,:old.object_name);
22 end if;
23 end;
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92. 9/19/2019
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a better, faster, robust version ...
218
flashback data archive
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93. 9/19/2019
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SQL> select empno, ename, job, sal, comm,
2 nvl(VERSIONS_STARTTIME,LAST_MOD) TS
3 ,nvl(VERSIONS_OPERATION,'I') op
4 from EMP
5 versions between timestamp
6 timestamp '2019-09-16 20:12:00' and systimestamp
7 order by empno, ts;
EMPNO ENAME JOB SAL COMM TS O
---------- ---------- --------- -------- ---------- ------------ -
7369 SMITH CLERK 806 08.10.51 PM I
7369 SMITH SALES 8060 1000 08.12.10 PM U
7499 ALLEN SALESMAN 1606 300000000 08.10.51 PM I
7521 WARD SALESMAN 1256 500000000 08.10.51 PM I
7566 JONES MANAGER 2981 08.10.51 PM I
...
7900 JAMES CLERK 956 08.10.51 PM I
7902 FORD ANALYST 3006 08.10.51 PM I
7934 MILLER CLERK 1306 08.10.51 PM I
7934 MILLER CLERK 1306 08.12.10 PM D
220
so why didn't we ?
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94. 9/19/2019
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separately licensed
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95. 9/19/2019
95
240
flashback data archive is now …
240
Copyright © 2018, Oracle and/or its affiliates. All rights reserved. | 241
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96. 9/19/2019
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242
not a typo
242
243
compression option
243
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97. 9/19/2019
97
266
wrap up
267
flashback query
flashback table
flashback drop
flashback database
flashback transaction
flashback data archive
266
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98. 9/19/2019
98
268
all cool for modern development
269
all included in EE
268
269

99. 9/19/2019
99
270
hanging around ?
271
PL/SQL: Still the Best Data Access Language
Thursday, September 19, 12:15 PM - 01:00 PM,
Moscone South - Room 155A
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100. 9/19/2019
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272
Thanks for attending !!!
youtube tinyurl.com/connortube
blog connor-mcdonald.com
twitter @connor_mc_d
272