描述

如果柵格 A 的邊界框與柵格 B 的邊界框重疊或位於其左側，或者更準確地說，如果與柵格 B 的邊界框重疊或「不在」其右側，則 &< 運算子返回 TRUE。

範例

SELECT A.rid As a_rid, B.rid As b_rid, A.rast &< B.rast As overleft
 FROM dummy_rast AS A CROSS JOIN dummy_rast AS B;

a_rid | b_rid | overleft
------+-------+----------
    2 |     2 | t
    2 |     3 | f
    2 |     1 | f
    3 |     2 | t
    3 |     3 | t
    3 |     1 | f
    1 |     2 | t
    1 |     3 | t
    1 |     1 | t