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Remove the << >> &< and &> operators for contrib/cube, which were

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wrong, but nobody noticed because they were also useless.
This commit is contained in:
Tom Lane
2005-06-27 01:19:43 +00:00
parent 54c80a3434
commit dcf2e1c8c7
7 changed files with 13 additions and 978 deletions
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39
contrib/cube/README.cube
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@ -181,7 +181,7 @@ numbers with more than about 16 significant digits will be truncated.
USAGE
=====
The access method for CUBE is a GiST (gist_cube_ops), which is a
The access method for CUBE is a GiST index (gist_cube_ops), which is a
generalization of R-tree. GiSTs allow the postgres implementation of
R-tree, originally encoded to support 2-D geometric types such as
boxes and polygons, to be used with any data type whose data domain
@ -193,42 +193,21 @@ things, all geometric data types, regardless of their dimensionality
The operators supported by the GiST access method include:
a = b Same as
[a, b] << [c, d] Is left of
The cubements a and b are identical.
The left operand, [a, b], occurs entirely to the left of the
right operand, [c, d], on the axis (-inf, inf). It means,
[a, b] << [c, d] is true if b < c and false otherwise
a && b Overlaps
[a, b] >> [c, d] Is right of
The cubements a and b overlap.
[a, b] is occurs entirely to the right of [c, d].
[a, b] >> [c, d] is true if b > c and false otherwise
a @ b Contains
[a, b] &< [c, d] Over left
The cubement a contains the cubement b.
The cubement [a, b] overlaps the cubement [c, d] in such a way
that a <= c <= b and b <= d
a ~ b Contained in
[a, b] &> [c, d] Over right
The cubement [a, b] overlaps the cubement [c, d] in such a way
that a > c and b <= c <= d
[a, b] = [c, d] Same as
The cubements [a, b] and [c, d] are identical, that is, a == b
and c == d
[a, b] @ [c, d] Contains
The cubement [a, b] contains the cubement [c, d], that is,
a <= c and b >= d
[a, b] @ [c, d] Contained in
The cubement [a, b] is contained in [c, d], that is,
a >= c and b <= d
The cubement a is contained in b.
Although the mnemonics of the following operators is questionable, I
preserved them to maintain visual consistency with other geometric