This Oracle DML Locks Technical Documentation describes about the following
- What is a Lock?
- What are the types of Locks?
- Why Locks Occur?
- What we can do to prevent locks?
- An Example scenario of when a lock occurs and how it can be prevented next time.
Attached Document contains the below table of contents
Oracle Lock Modes
Share Lock Mode
Exclusive Lock Mode
Difference between Exclusive and shared lock
Oracle DML Lock Types
Row Level Locks [TX]
Table Level Locks [TM]
Row Share Table Lock (RS)
Row Exclusive Table Lock (RX)
Share Table Lock (S)
Share Row Exclusive Table Lock (SRX)
Exclusive Table Lock (X)
TM Lock Example
Locking with No Index on a Foreign Key
Locking with Index on a Foreign Key
Effects of Table Lock
Table Dead Lock Recovery
Preventing the Deadlocks
Identifying and fixing the cause for locks
Query to find Blocking Locks
Query to find all the Missing Foreign Key Indexes
Download Oracle DML Locks Technical Documentation