Jim C. Nasby wrote:
... how many pages per bit ...
Are we trying to set up a complex solution to a problem that'll be mostly moot once partitioning is easier and partitioned tables are common? In many cases I can think of the bulk of the data would be in old partitions that are practically never written to (so would need no vacuuming and could always use index-only lookups); while the hot parts of large tables would be on partitions that would need frequent vacuuming and wouldn't benefit from index-only lookups. In these cases, 1 bit per partition would work well, and seems a lot easier to keep track of than bits-per-page. ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match