G
gus bjorklund
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i’m not quite sure what you are asking, george. the terminology is a bit inconsistent in places and also the implementation details have changed over time some of the differences in terminology are due to the age of the writings. take the buffer pool for an example. currently, each buffer has its own latch. in promon these are grouped together and the counters are summed and reported under BUF1, BUF2, BUF3, and BUF4. so they are “multiplexed” only for reposting purposes. in earlier times, there were another type of locks that were called multiplexed latches or muxlatches, where each buffer was assigned to one of several multiplexed locks that were each under a governing latch (called BUF1, BUF2, BUF3, and BUF4). i wont explain how these work since they are obsolete. either way, those were all in shared memory and the latches can be manipulated by any local database connection. however, there is some code which is used to operate on shared data structures and on private data structures (i.e data structures that are in process private memory). since the code locks and unlocks latches, we put in”private latches” for the data structures that are in process private memory. given that they are process private, they can be manipluated only by threads in the process.
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