The pg_cast catalog provides information about data type conversion paths.
| Column name | Data type | Description |
|---|---|---|
oid |
oid |
A row identifier used to reference the catalog entry internally. |
castsource |
oid (references pg_type.oid) |
The OID of the source data type from which the cast starts. |
casttarget |
oid (references pg_type.oid) |
The OID of the target data type to which the cast converts values. |
castfunc |
oid |
The OID of the function used to perform the cast. 0 – The cast method does not require a function. |
castcontext |
char |
The context in which the cast can be invoked, whether explicitly (e), implicitly during assignment (a), or implicitly in expressions (i). |
castmethod |
char |
The method used to perform the cast, whether by calling a function (f), by using input/output functions (i), or by treating the types as binary-coercible (b), requiring no conversion. |