PG_CAST
PG_CAST records conversion relationships between data types.
Table 1 PG_CAST columnsName | Type | Description |
|---|
castsource | oid | OID of the source data type |
casttarget | oid | OID of the target data type |
castfunc | oid | OID of the conversion function. If the value is 0, no conversion function is required. |
castcontext | "char" | Conversion mode between the source and target data types e indicates that only explicit conversion can be performed (using the CAST or :: syntax). i indicates that only implicit conversion can be performed. a indicates that both explicit and implicit conversion can be performed between data types.
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castmethod | "char" | Conversion method f indicates that conversion is performed using the specified function in the castfunc column. b indicates that binary forcible conversion rather than the specified function in the castfunc column is performed between data types.
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