Hybrid Buffer Pool and PMEM
Eliminating latency is the goal of optimization and persistent memory. PMEM, or storage class memory, is a new tool that helps by bypassing making a copy of data in the clean pages area of the buffer pool and instead stores these pages in PMEM so that they can be directly accessed in a new feature called Hybrid Buffer Pool.
PMEM stands for persistent memory, and it's an area of non-volatile storage that performs similarly to memory. As the term can also be used to describe hardware, there may be some confusion as to what it's called, the following should clarify this:
- PMEM or PM (Persistent Memory) This is the correct term for SQL Server 2019
- Storage Class Memory (SCM)
- Non-Volatile Memory (NVM)
- Byte-Addressable Storage (BAS)
For SQL Server 2019, PMEM is part of the memory bus and eliminates I/O latency. It does this by eliminating the extra need to copy pages to DRAM or the I/O penalty of going...