Sukanya Srinivas

• Apr 20th, 2007

 

Lock is one of the component of DB2. IRLM(IMS-DBe Resource lock Manager) used for data locking and unlocking. Lock is of two types.

1) Share lock
2) Exclusive Lock      

A) Share lock is applicalble whenever any program reads data from DB2 table.           


B) Exclusive lock is applicable whenever any program updates  (INSERT,DELETE,UPDATE) any DB2 table.

Raghunathan Asari

• Jul 23rd, 2007

 

Lock is a DB2 mechanism by which DB2 can provide Concurrency and Consistency at 
the same time(not exactly).  Based on the SQL statement DB2 provides different  types
of locks. They are
   1. SHARED LOCK (S)
   2. UPDATE LOCK (U)
   3. EXCLUSIVE LOCK (X)
Apart from the above mentioned locks, DB2 uses another type of lock called "intent" lock. This intent lock can be converted into IS( Intent Share), IX( Intent Exclusive ) and
SIX (Share with Intent Exclusive) locks.