Although Six Mode Is Useful In Multiple-granularity Locking, An Exclu

1.	Although Six Mode Is Useful In Multiple-granularity Locking, An Exclusive And Intend-shared (xis) Mode Is Of No Use. Why Is It Useless?
Answer» An EXCLUSIVE lock is incompatible with any other lock kind. Once a node is locked in exclusive mode, NONE of the descendents can be SIMULTANEOUSLY accessed by any other transaction in any mode. Therefore an exclusive and intend-shared declaration has no MEANING. An exclusive lock is incompatible with any other lock kind. Once a node is locked in exclusive mode, none of the descendents can be simultaneously accessed by any other transaction in any mode. Therefore an exclusive and intend-shared declaration has no meaning.

Although Six Mode Is Useful In Multiple-granularity Locking, An Exclusive And Intend-shared (xis) Mode Is Of No Use. Why Is It Useless?

Answer»

An EXCLUSIVE lock is incompatible with any other lock kind. Once a node is locked in exclusive mode, NONE of the descendents can be SIMULTANEOUSLY accessed by any other transaction in any mode. Therefore an exclusive and intend-shared declaration has no MEANING.

An exclusive lock is incompatible with any other lock kind. Once a node is locked in exclusive mode, none of the descendents can be simultaneously accessed by any other transaction in any mode. Therefore an exclusive and intend-shared declaration has no meaning.

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