On 2008-12-06, at 11:29, David Lee Lambert wrote:
I use "ORDER BY random() LIMIT :some_small_number" frequently to get
a "feel"
for data. That always builds the unrandomized relation and then
sorts it. I
guess an alternate path for single-table queries would be to
randomly choose
a block number and then a tuple number; but that would be biased
toward long
rows (of which fewer can appear in a block).
but that's going to be extremely slow, due to speed of random()
function.
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