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The PostgreSQL 9.0 Reference Manual - Volume 1A - SQL Language Reference
by The PostgreSQL Global Development Group
Paperback (6"x9"), 454 pages
ISBN 9781906966041
RRP £14.95 ($19.95)

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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.

ISBN 9781906966041The PostgreSQL 9.0 Reference Manual - Volume 1A - SQL Language ReferenceSee the print edition