Strict and Conservative 2PL

Question

We know, Conservative 2PL is another name of Strict 2PL. But According to Navathe book

Conservative 2PL is deadlock free,but Strict 2PL can have deadlock.

Then how both could be same??

Comments

Conservative is another name for static 2PL.

Ref:- https://www.coursehero.com/file/p5mk1tc/conservative-2PL-or-static-2PL-requires-a-transaction-to-lock-all-the-items-it/

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2PL...Problem with 2PL is that it serializable but not..

1.not recoverable

2.not casadeless

3. deadlock possible....

therefor we study modified 2PL....

which is ..

1.strict 2PL

2.Regrous 2PL

3.Conservative 2PL ...s

Note:- Strict 2PL is the modified 2PL(here we are strict to unlock the x-clusive locks only after the commitement of transaction)

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but any book u search

it is told Conservative 2PL or Stict 2 PL

ok,

So, conservative 2PL is a extension on strict 2PL

right??

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yes .....

i think u must read definition of all these three once for more clarification.......

Answer 1

As far as I know, Strict 2PL and Conservative 2PL are different.

In Strict 2PL, xclusive locks are held until commit is performed.

In Conservative 2PL, first all locks are held and then any action is performed. In this case, the transaction would be deadlock free.

Source- RBR lectures