Oracle Database Discussions

Hi

oracle has two type of locks

Dml locks and DDL locks.

DML LOCKS
Table level locks
row level locks
partition locks

I will only discuss DML locks so skiping DDL locks

Now row level lock (Rx) are set by a byte in the row head of a blocks.
TM lock is set by ........(dont know may be by set a byte at segament level)
Partition locks .......... find no information about it..

also from documentation i found the following locks

RS (row share) ......... How its set internal at block level
SRX (Share row exclusive ). ..................
X (Exclusive)

I know oracle locks at lowest level. The purpose of this thread should be under which conditions these locks were used and how they are implemented internal at block level ..

Thanks
Nicks