-- PLE QUERY /* 1. All NUMAs have good PLE if (ple_per_4GB is > 300 sec) 2. If ple_per_4gb<300, memory is not reused efficiently as the performance will rely on the disk which is much slower than memory, and will generate a lot of disk IO and stress the storage. So, by looking at the PLE normalized to 4GB and per numa node, we can spot the opportunity for optimization and investigate further (which objects are using the most of buffer cache memory, the distribution of “hotness” of it’s indexes and partitions etc). */
-- DBCC DROPCLEANBUFFERS only drops clean pages /* DROPCLEANBUFFERS drops clean pages from the buffer pool only. A clean page is one that has not been changed since it was read into memory or last written to disk. A dirty page is one that has not been written to disk since it was last changed. Dirty pages are not dropped by DBCC DROPCLEANBUFFERS, they are only made clean by writing them to disk (either through one of the various kinds of checkpoints or by the lazy writer – or one of the per-NUMA node lazy writers if you have NUMA configured). */