Re: Relation extension scalability

One thing that is slightly unclear is that whether there is any overhead due to buffer eviction especially when the buffer to be evicted is already dirty and needs XLogFlush().  One reason why it might not hurt is that by the time we tries to evict the buffer, corresponding WAL is already flushed by WALWriter or other possibility could be that even if it is getting done during buffer eviction, the impact for same is much lesser.  Can we try to measure the number of flush calls which happen during buffer eviction?

 

Proc Sleep test for Insert test when data don't fits in shared buffer and inserting big record of 1024 bytes, is currently running

once I get the data will post the same.

Okay.  However, I wonder if the performance data for the case when data doesn't fit into shared buffer also shows similar trend, then it might be worth to try by doing extend w.r.t load in system.  I mean to say we can batch the extension requests (as we have done in ProcArrayGroupClearXid) and extend accordingly, if that works out then the benefit could be that we don't need any configurable knob for the same.