Postgresql 中文操作指南
53.43. pg_range #
目录 pg_range 存储有关范围类型的信息。这将添加到 pg_type 中类型的条目。
The catalog pg_range stores information about range types. This is in addition to the types' entries in pg_type.
Table 53.43. pg_range Columns
Table 53.43. 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（加上 rngcollation，如果元素类型可整理）决定范围类型所使用的排序顺序。如果元素类型是离散的，则使用 rngcanonical。rngsubdiff 是可选的，但应该提供以提高 GiST 对范围类型的索引性能。
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.