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3.3.6 Exclusion constraints

Exclusion constraints ensure that if any two rows are compared on the specified columns or expressions using the specified operators, at least one of these operator comparisons will return false or null. The syntax is:

CREATE TABLE circles (
    c circle,
    EXCLUDE USING gist (c WITH &&)
);

See also CREATE TABLE ... CONSTRAINT ... EXCLUDE (see Volume 1B: 1.59 CREATE TABLE) for details.

Adding an exclusion constraint will automatically create an index of the type specified in the constraint declaration.