Hello , Need to know about monetdb eviction policy ? My understanding is Monetdb creates a buffer pool {BBP} and inserts all the bats that are used . But not sure when does Monetdb deletes the bat from the buffer pool and what eviction policy does it use (like LRU or based on some threshold) ?
Thanks
Hi Narendra,
despite its possibly misleading name, MonetD's BBP has nothing to do with a classical database buffer pool. No such thing exists in MonetDB. BBP is more a catalog of all (both persistent and transient) BATs rather than a buffer pool.
And to also answer one of your recent questions, there is no way to determine whether a BAT is physically in memory or not in MonetDB. Using memory mapped files, MonetDB leaves it to the operting systems virtual memory management to control when which (parts of --- on a memory page-wise granularity --- which) BAT(s) are in physical memory.
Best, Stefan
----- On Sep 15, 2016, at 8:52 AM, Narendra Pradeep narenpradeeptigers@gmail.com wrote:
Hello , Need to know about monetdb eviction policy ? My understanding is Monetdb creates a buffer pool {BBP} and inserts all the bats that are used . But not sure when does Monetdb deletes the bat from the buffer pool and what eviction policy does it use (like LRU or based on some threshold) ?
Thanks
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participants (2)
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Narendra Pradeep
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Stefan Manegold