Tag: Mutex

High “cursor: pin S wait on X” waits?

If your system meets any of the following criteria: – Oracle 12.1.0.2.0 or higher – Partitioned tables – Parallel query heavily used – Bind variables in use, as they should be and, you’re seeing unusually high “cursor: pin S wait…

Read More >

Log Buffer #429: A Carnival of the Vanities for DBAs

This Log Buffer Edition gathers a wide sample of blogs and then purifies the best ones from Oracle, SQL Server and MySQL.

Read More >

Locks, Latches, Mutexes, and CPU Usage

So how is the actual “waiting on lock” implemented? How does session B, waiting for a transaction to commit started by session A, knows that the resource is free for use? To find out how it is implemented, I have traced Oracle foreground processes. I tried this on Oracle RDBMS 11.2.0.3 running on Linux. This is a excerpt of system calls being executed during a session waiting for a lock…

Read More >