latch: cache buffers chains – Oracle wait event

The Buffer cache is implemented as a chain of blocks linked together under a hash value known as cache buffer chains (CBC). When a buffer is requested the hash value of the chain where the buffer is, will be calculated and then that chain is scanned by walking the chain until the buffer is found.…

Oracle Locking Mechanism – Latches & Enqueues

This article is part of Oracle Performance Tuning Series and is created to describe Oracle’s locking mechanism. A lock is a resource that you need to hold to get access to the resource. Oracle has two kind of locks: enqueues and latches, we would now focus on these locking mechanism individually. Enqueues Enqueues are sophisticated…