Oracle RMAN backup sets → Parquet

Datatypes conversion mapping when exporting a table from Oracle RMAN backup sets using the ArpeOraBackup ADBC driver (--connectiontype backup_rman) to Parquet format.

Platform availability

backup_rman is available on Windows x64 and Linux x64 only. It is not supported on Linux ARM64.

Compared with adbc_oracle

For the types both connectors read, the mapping is the one of adbc_oracle, with the same values.

Source	Oracle RMAN backup sets (backup_rman)
Format	Parquet
FastBCP	1.6.1.0
Test Status	OK (16/16 Nullable) — Oracle 19c, 23ai and 26ai backups, every compression

Parquet Schema

Oracle type	physical_type	converted_type	logical_type
NUMBER(10)	INT64	—	—
NUMBER	BYTE_ARRAY	UTF8	StringType()
NUMBER(18)	INT64	—	—
NUMBER(12,4)	FIXED_LEN_BYTE_ARRAY	DECIMAL	DecimalType(scale=4, precision=12)
NUMBER(38)	FIXED_LEN_BYTE_ARRAY	DECIMAL	DecimalType(scale=0, precision=38)
VARCHAR2(200)	BYTE_ARRAY	UTF8	StringType()
CHAR(10)	BYTE_ARRAY	UTF8	StringType()
NVARCHAR2(100)	BYTE_ARRAY	UTF8	StringType()
NCHAR(5)	BYTE_ARRAY	UTF8	StringType()
BINARY_FLOAT	FLOAT	—	—
BINARY_DOUBLE	DOUBLE	—	—
DATE	INT64	TIMESTAMP_MILLIS	TimestampType(isAdjustedToUTC=0, unit=MILLIS)
TIMESTAMP(0)	INT64	TIMESTAMP_MILLIS	TimestampType(isAdjustedToUTC=0, unit=MILLIS)
TIMESTAMP(6)	INT64	TIMESTAMP_MICROS	TimestampType(isAdjustedToUTC=0, unit=MICROS)
TIMESTAMP(9)	INT64	—	TimestampType(isAdjustedToUTC=0, unit=NANOS)
RAW(100)	BYTE_ARRAY	—	—

Notes

• NUMBER(p) and NUMBER(p,0) with p up to 18 are written as 64-bit integers; larger precisions and NUMBER(p,s) as decimals of the declared precision and scale.
• NUMBER without precision is written as text: the exact decimal value, without exponent (0.0123).
• DATE and TIMESTAMP keep the stored value, without time zone (isAdjustedToUTC=0). The unit follows the declared precision: milliseconds for DATE and TIMESTAMP(0) to TIMESTAMP(3), microseconds for TIMESTAMP(4) to TIMESTAMP(6), nanoseconds for TIMESTAMP(7) to TIMESTAMP(9).
• Text is converted to UTF-8 from the database character set (VARCHAR2, CHAR) or from the national character set (NVARCHAR2, NCHAR). CHAR and NCHAR values keep their trailing spaces, as Oracle stores them. Oracle stores an empty string as NULL: it is exported as NULL.
• BINARY_FLOAT and BINARY_DOUBLE keep their exact value.

Refused columns

LOB (CLOB, NCLOB, BLOB, BFILE), INTERVAL, ROWID / UROWID, JSON, VECTOR, XMLTYPE and object columns cannot be exported: a table with such a column is refused with a message naming the column. Export the other columns by listing them in --query.