native barcode generator for crystal reports free download LOCKING AND LATCHING in Objective-C

Drawer ECC200 in Objective-C LOCKING AND LATCHING

CHAPTER 6 LOCKING AND LATCHING
Making DataMatrix In Objective-C
Using Barcode generator for iPhone Control to generate, create Data Matrix 2d barcode image in iPhone applications.
www.OnBarcode.com
USS Code 128 Creator In Objective-C
Using Barcode creation for iPhone Control to generate, create Code 128A image in iPhone applications.
www.OnBarcode.com
ops$tkyte%ORA11GR2> create table dept 2 as select * from scott.dept; Table created. ops$tkyte%ORA11GR2> create table emp 2 as select * from scott.emp; Table created. ops$tkyte%ORA11GR2> alter table dept 2 add constraint dept_pk 3 primary key(deptno); Table altered. ops$tkyte%ORA11GR2> alter table emp 2 add constraint emp_pk 3 primary key(empno); Table altered. ops$tkyte%ORA11GR2> alter table emp 2 add constraint emp_fk_dept 3 foreign key (deptno) 4 references dept(deptno); Table altered. ops$tkyte%ORA11GR2> create index emp_deptno_idx 2 on emp(deptno); Index created. Let s start a transaction now: ops$tkyte%ORA11GR2> update dept 2 set dname = initcap(dname); 4 rows updated. Now, let s look at the state of the system at this point. This example assumes a single-user system; otherwise, you may see many rows in V$TRANSACTION. Even in a single-user system, do not be surprised to see more than one row in V$TRANSACTION, as many of the background Oracle processes may be performing a transaction as well. ops$tkyte%ORA11GR2> select username, 2 v$lock.sid, 3 trunc(id1/power(2,16)) rbs, 4 bitand(id1,to_number('ffff','xxxx'))+0 slot, 5 id2 seq, 6 lmode, 7 request 8 from v$lock, v$session 9 where v$lock.type = 'TX' 10 and v$lock.sid = v$session.sid 11 and v$session.username = USER;
Encode Barcode In Objective-C
Using Barcode printer for iPhone Control to generate, create Barcode image in iPhone applications.
www.OnBarcode.com
USS-128 Maker In Objective-C
Using Barcode generation for iPhone Control to generate, create UCC - 12 image in iPhone applications.
www.OnBarcode.com
CHAPTER 6 LOCKING AND LATCHING
GTIN - 13 Encoder In Objective-C
Using Barcode encoder for iPhone Control to generate, create EAN-13 image in iPhone applications.
www.OnBarcode.com
DataMatrix Maker In Objective-C
Using Barcode generator for iPhone Control to generate, create Data Matrix ECC200 image in iPhone applications.
www.OnBarcode.com
USERNAME SID RBS SLOT SEQ LMODE REQUEST --------- ---------- ---------- ---------- ---------- ---------- ---------OPS$TKYTE 703 2 26 8297 6 0 ops$tkyte%ORA11GR2> select XIDUSN, XIDSLOT, XIDSQN 2 from v$transaction; XIDUSN XIDSLOT XIDSQN ---------- ---------- ---------2 26 8297 The interesting points to note here are as follows: The LMODE is 6 in the V$LOCK table and the request is 0. If you refer to the definition of the V$LOCK table in the Oracle Server Reference manual, you will find that LMODE=6 is an exclusive lock. A value of 0 in the request means you are not making a request; you have the lock. There is only one row in this table. This V$LOCK table is more of a queuing table than a lock table. Many people expect four rows in V$LOCK since we have four rows locked. Remember, however, that Oracle does not store a master list of every row locked anywhere. To find out if a row is locked, we must go to that row. I took the ID1 and ID2 columns and performed some manipulation on them. Oracle needed to save three 16-bit numbers, but only had two columns in order to do it. So, the first column ID1 holds two of these numbers. By dividing by 2^16 with trunc(id1/power(2,16)) rbs, and by masking out the high bits with bitand(id1,to_number('ffff','xxxx'))+0 slot, I am able to get back the two numbers that are hiding in that one number. The RBS, SLOT, and SEQ values match the V$TRANSACTION information. This is my transaction ID.
Draw Code 3 Of 9 In Objective-C
Using Barcode drawer for iPhone Control to generate, create Code 39 image in iPhone applications.
www.OnBarcode.com
EAN / UCC - 8 Drawer In Objective-C
Using Barcode printer for iPhone Control to generate, create GTIN - 8 image in iPhone applications.
www.OnBarcode.com
Now we ll start another session using the same username, update some rows in EMP, and then try to update DEPT: ops$tkyte%ORA11GR2> update emp set ename = upper(ename); 14 rows updated. ops$tkyte%ORA11GR2> update dept set deptno = deptno-10; We re now blocked in this session. If we run the V$ queries again, we see the following: ops$tkyte%ORA11GR2> select username, 2 v$lock.sid, 3 trunc(id1/power(2,16)) rbs, 4 bitand(id1,to_number('ffff','xxxx'))+0 slot, 5 id2 seq, 6 lmode, 7 request 8 from v$lock, v$session 9 where v$lock.type = 'TX' 10 and v$lock.sid = v$session.sid 11 and v$session.username = USER;
Decoding Data Matrix ECC200 In .NET
Using Barcode recognizer for VS .NET Control to read, scan read, scan image in VS .NET applications.
www.OnBarcode.com
Making Data Matrix In None
Using Barcode printer for Font Control to generate, create Data Matrix 2d barcode image in Font applications.
www.OnBarcode.com
CHAPTER 6 LOCKING AND LATCHING
Draw Barcode In Visual Studio .NET
Using Barcode creator for VS .NET Control to generate, create Barcode image in Visual Studio .NET applications.
www.OnBarcode.com
UPC-A Supplement 2 Decoder In Java
Using Barcode decoder for Java Control to read, scan read, scan image in Java applications.
www.OnBarcode.com
USERNAME SID RBS SLOT SEQ LMODE REQUEST --------- ---------- ---------- ---------- ---------- ---------- ---------OPS$TKYTE 7 2 26 8297 0 6 OPS$TKYTE 703 2 26 8297 6 0 OPS$TKYTE 7 7 13 8215 6 0 ops$tkyte%ORA11GR2> ops$tkyte%ORA11GR2> select XIDUSN, XIDSLOT, XIDSQN 2 from v$transaction; XIDUSN XIDSLOT XIDSQN ---------- ---------- ---------2 26 8297 7 13 8215 What we see here is that a new transaction has begun, with a transaction ID of (7,13,8215). Our new session, SID=7, has two rows in V$LOCK this time. One row represents the locks that it owns (where LMODE=6). It also has a row that shows a REQUEST with a value of 6. This is a request for an exclusive lock. The interesting thing to note here is that the RBS/SLOT/SEQ values of this request row are the transaction ID of the holder of the lock. The transaction with SID=703 is blocking the transaction with SID=7. We can see this more explicitly simply by doing a self-join of V$LOCK: ops$tkyte%ORA11GR2> select 2 (select username from v$session where sid=a.sid) blocker, 3 a.sid, 4 ' is blocking ', 5 (select username from v$session where sid=b.sid) blockee, 6 b.sid 7 from v$lock a, v$lock b 8 where a.block = 1 9 and b.request > 0 10 and a.id1 = b.id1 11 and a.id2 = b.id2; BLOCKER SID 'ISBLOCKING' BLOCKEE SID --------- ---------- ------------- --------- ---------OPS$TKYTE 703 is blocking OPS$TKYTE 7 Now, if we commit our original transaction, SID=703, and rerun our lock query, we find that the request row has gone: ops$tkyte%ORA11GR2> select username, 2 v$lock.sid, 3 trunc(id1/power(2,16)) rbs, 4 bitand(id1,to_number('ffff','xxxx'))+0 slot, 5 id2 seq, 6 lmode, 7 request 8 from v$lock, v$session 9 where v$lock.type = 'TX' 10 and v$lock.sid = v$session.sid 11 and v$session.username = USER;
UCC - 12 Drawer In .NET Framework
Using Barcode encoder for Reporting Service Control to generate, create GTIN - 128 image in Reporting Service applications.
www.OnBarcode.com
Generating ECC200 In Java
Using Barcode creation for Java Control to generate, create Data Matrix ECC200 image in Java applications.
www.OnBarcode.com
Barcode Recognizer In Visual C#
Using Barcode reader for Visual Studio .NET Control to read, scan read, scan image in .NET framework applications.
www.OnBarcode.com
Scanning GS1 128 In C#
Using Barcode scanner for .NET framework Control to read, scan read, scan image in Visual Studio .NET applications.
www.OnBarcode.com
Generating Barcode In .NET Framework
Using Barcode creation for ASP.NET Control to generate, create Barcode image in ASP.NET applications.
www.OnBarcode.com
Code 3 Of 9 Decoder In VB.NET
Using Barcode recognizer for .NET framework Control to read, scan read, scan image in Visual Studio .NET applications.
www.OnBarcode.com
Barcode Creation In .NET Framework
Using Barcode creator for .NET framework Control to generate, create Barcode image in .NET framework applications.
www.OnBarcode.com
Generating Denso QR Bar Code In None
Using Barcode creator for Online Control to generate, create QR Code image in Online applications.
www.OnBarcode.com
Copyright © OnBarcode.com . All rights reserved.