pub const HAS_DOUBLE: u8 = 1;Expand description
Set in ATTR_IDX when the block holds at least one double-typed
attribute.
Doubles are the one type not indexed. The canonical text of a float is not
unique — 200, 200.0 and 2e2 are the same number and three different
strings, and a query writing one of the forms the writer did not would be
pruned away. So the block declares that it has some, and any query whose
value could be read as a number scans it. Blocks with no double attributes,
which is most of them, pay nothing for the rule.