52.43. pg_range
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## 52.43. pg_range #

The catalog pg_range stores information about range types. This is in addition to the types' entries in pg_type.

Table 52.43. pg_range Columns

Column Type Description
`rngtypid` oid (references pg_type.`oid`) OID of the range type
`rngsubtype` oid (references pg_type.`oid`) OID of the element type (subtype) of this range type
`rngmultitypid` oid (references pg_type.`oid`) OID of the multirange type for this range type
`rngcollation` oid (references pg_collation.`oid`) OID of the collation used for range comparisons, or zero if none
`rngsubopc` oid (references pg_opclass.`oid`) OID of the subtype's operator class used for range comparisons
`rngcanonical` regproc (references pg_proc.`oid`) OID of the function to convert a range value into canonical form, or zero if none
`rngsubdiff` regproc (references pg_proc.`oid`) OID of the function to return the difference between two element values as double precision, or zero if none

`rngsubopc` (plus `rngcollation`, if the element type is collatable) determines the sort ordering used by the range type. `rngcanonical` is used when the element type is discrete. `rngsubdiff` is optional but should be supplied to improve performance of GiST indexes on the range type.

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