Apress.Expert.Oracle.Database.Architecture.9i.and.10g.Programming.Techniques.and.Solutions.Sep.2005

CHAPTER 9 ■ REDO AND UNDO 303
ops$tkyte@ORA10G> create or replace procedure do_work( p_what in varchar2 )
2 as
3 l_redo_size number;
4 l_cnt number := 200;
5
6 procedure report( l_op in varchar2 )
7 is
8 begin
9 select v$mystat.value-l_redo_size
10 into l_redo_size
11 from v$mystat, v$statname
12 where v$mystat.statistic# = v$statname.statistic#
13 and v$statname.name = 'redo size';
14
15 dbms_output.put_line(l_op || ' redo size = ' || l_redo_size ||
16 ' rows = ' || l_cnt || ' ' ||
17 to_char(l_redo_size/l_cnt,'99,999.9') ||
18 ' bytes/row' );
19 insert into log
20 select p_what, l_op, data_length, l_redo_size, l_cnt
21 from user_tab_columns
22 where table_name = 'T'
23 and column_name = 'Y';
24 end;
The local procedure SET_REDO_SIZE queries V$MYSTAT and V$STATNAME to retrieve the current
amount of redo our session has generated thus far. It sets the variable L_REDO_SIZE in the
procedure to that value:
25 procedure set_redo_size
26 as
27 begin
28 select v$mystat.value
29 into l_redo_size
30 from v$mystat, v$statname
31 where v$mystat.statistic# = v$statname.statistic#
32 and v$statname.name = 'redo size';
33 end;
And then there is the main routine. It collects the current redo size, runs an INSERT/
UPDATE/DELETE, and then saves the redo generated by that operation to the LOG table:
34 begin
35 set_redo_size;
36 insert into t
37 select object_id, object_name, created
38 from all_objects
39 where rownum