Re: Design notes for BufMgrLock rewrite

>>>>> "Tom" == Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> writes:

Tom> and changing the buf_table hash table. The only common
Tom> operation that needs exclusive lock is reading in a page that
Tom> was not in shared buffers already, which will require at
Tom> least a kernel call and usually a wait for I/O, so it will be
Tom> slow anyway.

Why not a separate lock per bucket chain in the hash table in addition
to the system-wide LWLock ? It's not so much that such an operation will be
slow anyway but that such a slow operation will unnecessarily block
other operations.

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Sailesh
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