Oracle中锁定行的查找方法

锁定行的查找

要查找session锁定的行，可以有两种方式：

1. 通过v$session中的row_wait_row#查询

set serverout on size 1000000

set lines 132

declare

cursor cur_lock is

select sid,id1,id2,inst_id, ctime

from gv$lock

where block = 1;

vid1 number;

vid2 number;

cursor cur_locked is

select sid, inst_id, ctime

from gv$lock

where id1 = vid1

and id2 = vid2

and block <> 1;

vlocks varchar2(30);

vsid1 number;

vobj1 number;

vfil1 number;

vblo1 number;

vrow1 number;

vrowid1 varchar2(20);

vcli1 varchar2(64);

vobj2 number;

vfil2 number;

vblo2 number;

vrow2 number;

vrowid2 varchar2(20);

vcli2 varchar2(64);

vobjname varchar2(30);

vlocked varchar2(30);

ctim1 number;

ctim2 number;

begin

dbms_output.put_line('=====================================================');

dbms_output.put_line('Blocking lock list.');

dbms_output.put_line('=====================================================');

dbms_output.put_line('Block / Is blocked SID INST_ID OBJECT TIME(secs) ROWID CLIENT_IDENTIFIER');

dbms_output.put_line('------------------------- --------- ------- ------------------------------ ---------- ------------------ -----------------');

for c1 in cur_lock loop

vid1 := c1.id1;

vid2 := c1.id2;

select username,sid,row_wait_obj#,row_wait_file#,row_wait_block#,row_wait_row#,client_identifier

into vlocks,vsid1,vobj1,vfil1,vblo1,vrow1,vcli1

from gv$session where sid = c1.sid and inst_id = c1.inst_id;

if vobj1 = -1 then

vobjname := 'UNKNOWN';

else

select name into vobjname from sys.obj$ where obj# = vobj1;

select decode(vrow1,0,'MANY ROWS',dbms_rowid.rowid_create(1, vobj1, vfil1, vblo1, vrow1)) into vrowid1 from dual;

end if;

dbms_output.put_line(rpad(vlocks,25) || ' ' ||

to_char(vsid1,'999999999') || ' ' ||

to_char(c1.inst_id,'9999999') || ' ' ||

rpad(vobjname,30) || ' ' ||

to_char(c1.ctime,'999999999') || ' ' || rpad(vrowid1,18) || ' ' || vcli1);

for c2 in cur_locked loop

select username, row_wait_obj#,row_wait_file#,row_wait_block#,row_wait_row#

into vlocked, vobj2, vfil2, vblo2, vrow2

from gv$session where sid = c2.sid and inst_id = c2.inst_id;

if vobj2 = -1 then

vobjname := 'UNKNOWN';

else

select name into vobjname from sys.obj$ where obj# = vobj2;

select decode(vrow2,0,'MANY ROWS',dbms_rowid.rowid_create(1, vobj2, vfil2, vblo2, vrow2)) into vrowid2 from dual;

end if;

dbms_output.put_line(chr(9) || '--> ' || rpad(vlocked,12) || ' ' ||

to_char(c2.sid,'999999999') || ' ' ||

to_char(c2.inst_id,'9999999') || ' ' || rpad(vobjname,30) || ' ' ||

to_char(c2.ctime,'999999999') || ' ' || rpad(vrowid2,18) || ' ' || vcli2 ) ;

end loop;

end loop;

commit;

end;

这种查询方式的局限是只能查询出来一行，如果是多行，则row_wait_row#返回的是锁定的开始行。

2. 通过for update查询所有加锁行

create or replace procedure locksmith(table_name varchar2) is
type tabcurtype is ref cursor;
type tabrowstype is table of varchar2(50) index by binary_integer;
table_cursor tabcurtype;
rowid_table tabrowstype;
row_id rowid;
status number;
aud_sid number;
test_sid number;
test_serial number;
locker_sid number;
locker_name varchar2(1000);
message varchar2(1000);

resource_busy exception;
pragma exception_init(resource_busy, -54);

begin
rowid_table(0) := '0';
dbms_output.enable(1000000);
open table_cursor for 'select rowid from ' || table_name;
loop
begin
fetch table_cursor
into row_id;
exit when table_cursor%notfound;
savepoint one_register;
execute immediate 'select 1 from ' || table_name ||
' where rowid =:r for update nowait'
using row_id;
exception
when resource_busy then
rowid_table(rowid_table.last + 1) := row_id;
end;
rollback to savepoint one_register;
end loop;
close table_cursor;

for r in rowid_table.first + 1 .. rowid_table.last loop
dbms_output.put_line(rowid_table(r));
end loop;
rollback;
end;

使用nowait在表中循环所有记录，判断出所有加锁的行。

SQL> exec locksmith('TEST');

AAAM1tAAEAAAANWAAB

AAAM1tAAEAAAANWAAC

PL/SQL procedure successfully completed