Questions

[jomon_s]

Hi All.

I have a set of questions for you

1 ) Whats the protocol oracle uses to communicate between background processes & SGA.

2 ) One user has given a DML statement & a set of users are waiting for that lock.So once the lock is released who will lock next.Is this something related to latches.


Please help me.


Regards

Joe

[bang_dba]

hi,
May be it is Bequeth protocl....but i am not so sure about it.

Oracle keeps tracks of request for lock by a mechanism called Enques.
It knows which process has requested the lock first and services accordingly.

[vastdba]

Originally posted by bang_dba
hi,
May be it is Bequeth protocl....but i am not so sure about it.

Oracle keeps tracks of request for lock by a mechanism called Enques.
It knows which process has requested the lock first and services accordingly.

Hi,

1.It is the Server Process which is mediating between the BG processes to the SGA.

2. If a user is locking the particular ROW it will be under the process of manipulation so it will be locked otherwise will fall into deadlock.

OR
If it is a table lock then it is in construction of its meta data and will be locked till he evokes it.

Hope you got some idea with it.

VAST

[pando]

1) IPC, semaphores
2) It´s lock so we are in first in first out fashion, latches dont uses FIFO

[stmontgo]

read the concepts guide for an excellent description on latches and the various types of locking mechanisms oracle employs

[launchpad]

I recommend 'Oracle8i Internal Services for Waits, Latches, Locks, and Memory' by Steve Adams. It should give you clearer view of what's happening in background..

[stmontgo]

Originally posted by launchpad
I recommend 'Oracle8i Internal Services for Waits, Latches, Locks, and Memory' by Steve Adams. It should give you clearer view of what's happening in background..

I bought that and yeah is good but honestly I don't see anything
in that book that is not in the concepts guide. It's prety cheap anyway but it's all their in the concepts guide

[pando]

before read steve adams book read concept guide, that book is pretty advanced