为此新增优化器规则:识别JOIN+WHERE+ORDER BY+LIMIT组合模式,预扫描元数据表获取匹配键,通过DuckDB区域映射修剪跳过无关存储段,构建过滤位集执行ACORN-1筛选搜索,同时保留连接计划以便重新附加元数据列。
With named trait impls it would be possible to explicitly specify that BlanketTrait should be used, similarly it would also be possible to explicitly specify that TraitBound should be used.
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However, when you do have disk storage available (like an SSD), zram's block device architecture creates some significant constraints. The kernel is essentially naive to zram being any different from a typical block device on a slow disk, and so applies its normal disk-oriented defaults to it. As just one example, there is a kernel tunable called vm.page-cluster that decides how many pages we want to read ahead when we are faulting in a single swap page. It is logarithmic, so for example, if vm.page-cluster is 4, we would read in 2^4 pages to try to amortise disk work ahead of time while it's cheap and sequential. This is more important on hard drives, but there is still a meaningful performance delta between random and sequential reads even on modern NAND.
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