利用utl_file来读取文件.
以前写过用external table来加载trace文件,详情参考下面链接.
http://www.cnblogs.com/princessd8251/p/3779145.html
今天要做到是用UTL_FILE包来读取一个directory下面的文件,比如我们的trace文件.
先定义get_trace_file 函数.
-- create directory and varchar2 array
col value new_value user_dump_directory;
select value from v$parameter where name = 'user_dump_dest';
create or replace directory user_dump_dir as '&user_dump_directory';
create or replace type varchar2_array as table of varchar2(4000);
/ -- create get_trace_file1 function
create or replace function get_trace_file1(s_id number default userenv('sid'))
return varchar2_array
pipelined
as
v_handle utl_file.file_type;
v_filename varchar2(2000);
v_line varchar2(4000);
begin
-- get exact file_name
-- below code can be repaced by a query against v$diag_info if you are on Oracle 11G.
select i.value||'_ora_'||p.spid||decode(t.value,null,'','_'||t.value)||'.trc' into v_filename
from v$process p, v$session s,
(select value from v$parameter where name = 'instance_name') i,
(select value from v$parameter where name = 'tracefile_identifier') t
where p.addr = s.paddr and s.sid = s_id;
v_handle := utl_file.fopen('USER_DUMP_DIR', v_filename, 'R', 32767);
loop
begin
utl_file.get_line(v_handle, v_line);
exception when no_data_found then
exit;
end;
pipe row(v_line);
end loop;
utl_file.fclose(v_handle);
return;
end;
/ -- create get_trace_file2 function
create or replace function get_trace_file2(file_name in varchar2)
return varchar2_array
pipelined
as
v_handle utl_file.file_type;
v_line varchar2(20000);
begin
v_handle := utl_file.fopen('USER_DUMP_DIR', file_name, 'R', 32767);
loop
begin
utl_file.get_line(v_handle, v_line);
exception
when no_data_found then
exit;
end;
pipe row(v_line);
end loop;
utl_file.fclose(v_handle);
return;
end;
/ -- create get_trace_file3 function
create or replace function get_trace_file3(dir_name in varchar2, file_name in varchar2)
return varchar2_array
pipelined
as
v_handle utl_file.file_type;
v_line varchar2(20000);
begin
v_handle := utl_file.fopen(dir_name, file_name, 'R', 32767);
loop
begin
utl_file.get_line(v_handle, v_line);
exception
when no_data_found then
exit;
end;
pipe row(v_line);
end loop;
utl_file.fclose(v_handle);
return;
end;
/
然后开启10046,并执行一个查询. alter session set events '10046 trace name context forever, level 8';
select count(*) from t1;
alter session set events '10046 trace name context off';
用函数get_trace_file1去查看内容.
select * from table(get_trace_file1); Dump file c:\oracle\admin\ukja10\udump\ukja10_ora_2820.trc
Thu Mar 19 15:10:10 2009
ORACLE V10.2.0.1.0 - Production vsnsta=0
vsnsql=14 vsnxtr=3
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options
Windows XP Version V5.1 Service Pack 2
CPU : 2 - type 586
Process Affinity : 0x00000000
Memory (Avail/Total): Ph:1481M/3070M, Ph+PgF:3140M/4960M, VA:1359M/2047M
Instance name: ukja10 Redo thread mounted by this instance: 1 Oracle process number: 16 Windows thread id: 2820, image: ORACLE.EXE (SHAD) *** ACTION NAME:() 2009-03-19 15:10:10.109
*** MODULE NAME:(SQL*Plus) 2009-03-19 15:10:10.109
*** SERVICE NAME:(UKJA10) 2009-03-19 15:10:10.109
*** SESSION ID:(157.1205) 2009-03-19 15:10:10.109
=====================
PARSING IN CURSOR #1 len=68 dep=0 uid=61 oct=42 lid=61 tim=172367882897 hv=740818757 ad='27e12b14'
alter session set events '10046 trace name context forever, level 8'
END OF STMT
...
Now I sort the buffer busy waits event by class# like this.
col class# format a10
col elapsed format 99.99 with t as (
select /*+ materialize */
column_value as line,
instr(column_value, 'ela=') ei,
instr(column_value, 'file#=') fi,
instr(column_value, 'block#=') bi,
instr(column_value, 'class#=') ci,
instr(column_value, 'obj#=') oi,
instr(column_value, 'tim=') ti
from table(get_trace_file2('trc_1.trc'))
--from table(get_trace_file2('trc_2.trc'))
where
instr(column_value, 'WAIT #2: nam=''buffer busy waits''') > 0
--instr(column_value, 'WAIT #11: nam=''buffer busy waits''') > 0
)
select
class#
, count(1) as cnt
, sum(elapsed)/1000000 as elapsed
from
(
select
substr(line, ei+4, fi-ei-4) as elapsed,
substr(line, fi+6, bi-fi-6) as file#,
substr(line, bi+7, ci-bi-7) as block#,
substr(line, ci+7, oi-ci-7) as class#,
substr(line, oi+5, ti-oi-5) as obj#,
substr(line, ti+4) as tim
from
t
) x
group by
class#
order by
2 desc, 3 desc;
What I’m actually doing is:
- trc_1.trc file contains the 10046 trace result with 40K extent size in ASSM.
- trc_2.trc file contains the 10046 trace result with 10M extent size in ASSM.
- 10 concurrent sessions insert into the table with 10046 trace enabled.
- I’d like to analyze how extent size affects the pattern of buffer contention.
Here is the result.
--when extent size is 40K
CLASS# CNT ELAPSED
---------- ---------- -------
8 285 1.40
1 215 4.64
4 42 .01
9 2 .00
19 1 .00
33 1 .00 -- when extent size is 10M
CLASS# CNT ELAPSED
---------- ---------- -------
8 1456 3.01
1 420 1.54
4 5 .00
35 2 .00
77 1 .00
See the diffference. With big extent size, we have major buffer contention on 1st level bitmap block(8). With (too) smaller extent size, the major contention is on data block(1).
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