Josh Berkus <josh(at)agliodbs(dot)com> writes:
>> One drawback to this is that it would require an additional lseek per table
>> while planning, but that doesn't seem like a huge penalty.
> Hmmm ... would the additional lseek take longer for larger tables, or would it
> be a fixed cost?
Should be pretty much a fixed cost: one kernel call per table.
regards, tom lane