PG_RANGE

PG_RANGE records information about range types.

This is in addition to the types' entries in PG_TYPE.

Table 1 PG_RANGE columns

Name

Type

Reference

Description

rngtypid

oid

PG_TYPE.oid

OID of the range type

rngsubtype

oid

PG_TYPE.oid

OID of the element type (subtype) of this range type

rngcollation

oid

PG_COLLATION.oid

OID of the collation used for range comparisons, or 0 if none

rngsubopc

oid

PG_OPCLASS.oid

OID of the subtype's operator class used for range comparisons

rngcanonical

regproc

PG_PROC.oid

OID of the function to convert a range value into canonical form, or 0 if none

rngsubdiff

regproc

PG_PROC.oid

OID of the function to return the difference between two element values as double precision, or 0 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.