Hi
so 14. 1. 2023 v 15:51 odesÃlatel hehaoc...@hotmail.com < hehaoc...@hotmail.com> napsal: > The default is enable_bitmapscan on. However, TPC-H.query17 get slower > running on my NVMe SSD (WD SN850) after switching on the parameter: latency > drop from 9secs to 16secs. During a B-tree Index Scan, bitmapscan > optimization converts random I/O into sequential. However, many users use > SSDs rather than HDDs. But they may not know the trick. Is there a > possibility that can change the default value to off? > I don't think it can be disabled by default. When you have fast SSD disk, then common setting is decreasing random_page_cost to some value to 2 or maybe 1.5 Regards Pavel > > Thanks! >
