pg_range
The catalog pg_range stores information about
range types. This is in addition to the types' entries in
pg_type.
Table 51.42. pg_range Columns
| Name | Type | References | Description |
|---|---|---|---|
rngtypid | oid | | OID of the range type |
rngsubtype | oid | | OID of the element type (subtype) of this range type |
rngcollation | oid | | OID of the collation used for range comparisons, or 0 if none |
rngsubopc | oid | | OID of the subtype's operator class used for range comparisons |
rngcanonical | regproc | | OID of the function to convert a range value into canonical form, or 0 if none |
rngsubdiff | regproc | | 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. rngsubdiff is optional but should be supplied to
improve performance of GiST indexes on the range type.