Indexing

GiST and SP-GiST indexes can be created for table columns of the tbox and stbox types. The GiST index implements an R-tree and the SP-GiST index implements an n-dimensional quad-tree. An example of creation of a GiST index in a column Box of type stbox in a table Trips is as follows:

CREATE TABLE Trips(TripID integer PRIMARY KEY, Trip tgeompoint, Box stbox);
CREATE INDEX Trips_Box_Idx ON Trips USING GIST(bbox);

A GiST or SP-GiST index can accelerate queries involving the following operators: &&, <@, @>, ~=, -|-, <<, >>, &<, &>, <<|, |>>, &<|, |&>, <</, />>, &</, /&>, <<#, #>>, &<#, and #&>.

In addition, B-tree indexes can be created for table columns of a bounding box type. For these index types, basically the only useful operation is equality. There is a B-tree sort ordering defined for values of bounding box types, with corresponding < and > operators, but the ordering is rather arbitrary and not usually useful in the real world. The B-tree support is primarily meant to allow sorting internally in queries, rather than creation of actual indexes.