Data type mappings in BigQuery

This page describes how Datastream maps data types from various source databases to their corresponding BigQuery data types. Learn how different data types convert when you migrate data to BigQuery, how BigQuery represents MongoDB binary JSON (BSON) documents, and how to query PostgreSQL array data as a BigQuery ARRAY data type.

Map data types

The following table lists data type conversions from supported source databases to the BigQuery destination.

Source database Source data type BigQuery data type
MySQL BIGINT(size) INT64
MySQL BIGINT (unsigned) DECIMAL
MySQL BINARY(size) STRING (hex encoded)
MySQL BIT(size) INT64
MySQL BLOB(size) STRING (hex encoded)
MySQL BOOL INT64
MySQL CHAR(size) STRING
MySQL DATE DATE
MySQL DATETIME(fsp) DATETIME
MySQL DECIMAL(precision, scale) If the precision value is ≤ 38 and the scale value is ≤ 9, then NUMERIC. Otherwise, BIGNUMERIC.
MySQL DOUBLE(size, d) FLOAT64
MySQL ENUM(val1, val2, val3, ...) STRING
MySQL FLOAT(precision) FLOAT64
MySQL FLOAT(size, d) FLOAT64
MySQL INTEGER(size) INT64
MySQL INTEGER (unsigned) INT64
MySQL

JSON

 JSON
MySQL LONGBLOB STRING (hex encoded)
MySQL LONGTEXT STRING
MySQL MEDIUMBLOB STRING (hex encoded)
MySQL MEDIUMINT(size) INT64
MySQL MEDIUMTEXT STRING
MySQL SET(val1, val2, val3, ...) STRING
MySQL SMALLINT(size) INT64
MySQL TEXT(size) STRING
MySQL TIME(fsp) INTERVAL
MySQL TIMESTAMP(fsp) TIMESTAMP
MySQL TINYBLOB STRING (hex encoded)
MySQL TINYINT(size) INT64
MySQL TINYTEXT STRING
MySQL VARBINARY(size) STRING (hex encoded)
MySQL VARCHAR STRING
MySQL YEAR INT64
Oracle ANYDATA UNSUPPORTED
Oracle BFILE UNSUPPORTED
Oracle BINARY DOUBLE FLOAT64
Oracle BINARY FLOAT FLOAT64
Oracle BLOB BYTES
Oracle CHAR STRING
Oracle CLOB STRING
Oracle DATE DATETIME
Oracle DOUBLE PRECISION FLOAT64
Oracle FLOAT(p) FLOAT64
Oracle INTERVAL DAY TO SECOND UNSUPPORTED
Oracle INTERVAL YEAR TO MONTH UNSUPPORTED
Oracle LONG or LONG RAW UNSUPPORTED
Oracle NCHAR STRING
Oracle NCLOB STRING
Oracle NUMBER STRING
Oracle NUMBER(precision=*) STRING
Oracle NUMBER(precision, scale<=0) If precision ≤ 18, then INT64. If 18 < precision ≤ 78, then map to parameterized decimal types. If precision ≥ 79, map to STRING.
Oracle NUMBER(precision, scale>0) If 0 < precision ≤ 78, then map to parameterized decimal types. If precision ≥ 79, map to STRING.
Oracle NVARCHAR2 STRING
Oracle RAW STRING
Oracle ROWID STRING
Oracle SDO_GEOMETRY UNSUPPORTED
Oracle SMALLINT INT64
Oracle TIMESTAMP TIMESTAMP
Oracle TIMESTAMP WITH TIME ZONE TIMESTAMP
Oracle UDT (user-defined type) UNSUPPORTED
Oracle UROWID UNSUPPORTED
Oracle VARCHAR STRING
Oracle VARCHAR2 STRING
Oracle XMLTYPE UNSUPPORTED
PostgreSQL ARRAY JSON
PostgreSQL BIGINT INT64
PostgreSQL BIT BYTES
PostgreSQL BIT VARYING BYTES
PostgreSQL BOOLEAN BOOLEAN
PostgreSQL BOX UNSUPPORTED
PostgreSQL BYTEA BYTES
PostgreSQL CHARACTER STRING
PostgreSQL CHARACTER VARYING STRING
PostgreSQL CIDR STRING
PostgreSQL CIRCLE UNSUPPORTED
PostgreSQL DATE DATE
PostgreSQL DOUBLE PRECISION FLOAT64
PostgreSQL ENUM STRING
PostgreSQL INET STRING
PostgreSQL INTEGER INT64
PostgreSQL INTERVAL INTERVAL
PostgreSQL JSON JSON
PostgreSQL JSONB JSON
PostgreSQL LINE UNSUPPORTED
PostgreSQL LSEG UNSUPPORTED
PostgreSQL MACADDR STRING
PostgreSQL MONEY FLOAT64
PostgreSQL NUMERIC If precision = -1, then STRING (BigQuery NUMERIC types require fixed precision). Otherwise, BIGNUMERIC or NUMERIC. For more information, see the Arbitrary precision numbers section in the PostgreSQL documentation.
PostgreSQL OID INT64
PostgreSQL PATH UNSUPPORTED
PostgreSQL POINT UNSUPPORTED
PostgreSQL POLYGON UNSUPPORTED
PostgreSQL REAL FLOAT64
PostgreSQL SMALLINT INT64
PostgreSQL SMALLSERIAL INT64
PostgreSQL SERIAL INT64
PostgreSQL TEXT STRING
PostgreSQL TIME TIME
PostgreSQL TIMESTAMP TIMESTAMP
PostgreSQL TIMESTAMP WITH TIME ZONE TIMESTAMP
PostgreSQL TIME WITH TIME ZONE TIME
PostgreSQL TSQUERY STRING
PostgreSQL TSVECTOR STRING
PostgreSQL TXID SNAPSHOT STRING
PostgreSQL UUID STRING
PostgreSQL XML STRING
SQL Server BIGINT INT64
SQL Server BINARY BYTES
SQL Server BIT BOOL
SQL Server CHAR STRING
SQL Server DATE DATE
SQL Server DATETIME2 DATETIME
SQL Server DATETIME DATETIME
SQL Server DATETIMEOFFSET TIMESTAMP
SQL Server DECIMAL If the scale value is ≤ 9 and the (precision - scale) value is ≤ 29, then NUMERIC. Otherwise, BIGNUMERIC.
SQL Server FLOAT FLOAT64
SQL Server IMAGE BYTES
SQL Server INT INT64
SQL Server MONEY NUMERIC
SQL Server NCHAR STRING
SQL Server NTEXT STRING
SQL Server NUMERIC If the scale value is ≤ 9 and the (precision - scale) value is ≤ 29, then NUMERIC. Otherwise, BIGNUMERIC.
SQL Server NVARCHAR STRING
SQL Server NVARCHAR(MAX) STRING
SQL Server REAL FLOAT64
SQL Server SMALLDATETIME DATETIME
SQL Server SMALLINT INT64
SQL Server SMALLMONEY NUMERIC
SQL Server TEXT STRING
SQL Server TIME TIME
SQL Server TIMESTAMP or ROWVERSION BYTES
SQL Server TINYINT INT64
SQL Server UNIQUEIDENTIFIER STRING
SQL Server VARBINARY BYTES
SQL Server VARBINARY(MAX) BYTES
SQL Server VARCHAR STRING
SQL Server VARCHAR(MAX) STRING
SQL Server XML STRING
Salesforce BOOLEAN BOOLEAN
Salesforce BYTE BYTES
Salesforce DATE DATE
Salesforce DATETIME DATETIME
Salesforce DOUBLE BIGNUMERIC
Salesforce INT INT64
Salesforce STRING STRING
Salesforce TIME TIME
Salesforce ANYTYPE
(can be either STRING, DATE, NUMBER, or BOOLEAN)		 STRING
Salesforce COMBOBOX STRING
Salesforce CURRENCY FLOAT64

Maximum allowed length is 18 digits.
Salesforce DATACATEGORYGROUPREFERENCE STRING
Salesforce EMAIL STRING
Salesforce ENCRYPTEDSTRING STRING
Salesforce ID STRING
Salesforce JUNCTIONIDLIST STRING
Salesforce MASTERRECORD STRING
Salesforce MULTIPICKLIST STRING
Salesforce PERCENT FLOAT64

Maximum allowed length is 18 digits.
Salesforce PHONE STRING
Salesforce PICKLIST STRING
Salesforce REFERENCE STRING
Salesforce TEXTAREA STRING

Maximum allowed length is 255 characters.
Salesforce URL STRING
Spanner (GoogleSQL) ARRAY JSON
Spanner (GoogleSQL) BOOL BOOLEAN
Spanner (GoogleSQL) BYTES BYTES
Spanner (GoogleSQL) DATE DATE
Spanner (GoogleSQL) FLOAT32 FLOAT64
Spanner (GoogleSQL) FLOAT64 FLOAT64
Spanner (GoogleSQL) INT64 INT64
Spanner (GoogleSQL) JSON JSON
Spanner (GoogleSQL) NUMERIC STRING
Spanner (GoogleSQL) STRING STRING
Spanner (GoogleSQL) TIMESTAMP TIMESTAMP WITH TIME ZONE
Spanner (GoogleSQL) UUID STRING
Spanner (GoogleSQL) PROTO UNSUPPORTED
Spanner (GoogleSQL) ENUM UNSUPPORTED
Spanner (PostgreSQL) ARRAY JSON
Spanner (PostgreSQL) BIGINT INT64
Spanner (PostgreSQL) BOOL BOOLEAN
Spanner (PostgreSQL) BYTEA BYTES
Spanner (PostgreSQL) DATE DATE
Spanner (PostgreSQL) DECIMAL STRING
Spanner (PostgreSQL) DOUBLE PRECISION FLOAT64
Spanner (PostgreSQL) FLOAT8 FLOAT64
Spanner (PostgreSQL) INT8 INT64
Spanner (PostgreSQL) JSONB JSON
Spanner (PostgreSQL) NUMERIC STRING
Spanner (PostgreSQL) TIMESTAMP WITH TIME ZONE TIMESTAMP WITH TIME ZONE
Spanner (PostgreSQL) TIMESTAMPZ TIMESTAMP WITH TIME ZONE
Spanner (PostgreSQL) UUID STRING
Spanner (PostgreSQL) VARCHAR STRING

MongoDB data types

MongoDB binary JSON (BSON) documents are written to BigQuery in MongoDB Extended JSON (v1) strict mode format. The following table shows how data types are represented in BigQuery, along with example values.

Source data type Example value BigQuery JSON type value
DOUBLE 3.1415926535 3.1415926535
STRING "Hello, MongoDB!" "Hello, MongoDB!"
ARRAY 
[
    "item1",
    123,
    true,
    { subItem: "object in array" }
  ]
["item1",123,true,{"subItem":"object in array"}]
BINARY DATA new BinData(0, "SGVsbG8gQmluYXJ5IERhdGE=") {"$binary":"SGVsbG8gQmluYXJ5IERhdGE=","$type":"00"}
BOOLEAN true true
DATE 2024-12-25T10:30:00.000+00:00 {"$date": 1735122600000}
NULL null null
REGEX /^mongo(db)?$/i {"$options":"i","$regex":"^mongo(db)?$"}
JAVASCRIPT function() {return this.stringField.length;} {"$code":"function() {\n return this.stringField.length;\n }"}
DECIMAL128 NumberDecimal("1234567890.1234567890") {"$numberDecimal":"1234567890.1234567890"}
OBJECTID ObjectId('673c5d8dbfe2e51808cc2c3d') {"$oid": "673c5d8dbfe2e51808cc2c3d"}
LONG 3567587327 {"$numberLong": "3567587327"}
INT32 42 42
INT64 1864712049423024127 {"$numberLong": "1864712049423024127"}
TIMESTAMP new Timestamp(1747888877, 1) {"$timestamp":{"i":1,"t":1747888877}}

Query a PostgreSQL array as a BigQuery array data type

To query a PostgreSQL array as a BigQuery ARRAY data type, convert the JSON values to a BigQuery array by using the BigQuery JSON_VALUE_ARRAY function:

  SELECT
    ARRAY(
      SELECT CAST(element AS TYPE)
      FROM UNNEST(JSON_VALUE_ARRAY(BQ_COLUMN_NAME, '$')) AS element
    ) AS array_col

Replace the following:

  • TYPE: the BigQuery type that matches the element type in the PostgreSQL source array. For example, if the source type is an array of BIGINT values, then replace TYPE with INT64. For more information about how to map the data types, see Map data types.
  • BQ_COLUMN_NAME: the name of the relevant column in the BigQuery table.

There are two exceptions to the way that you convert the values:

  • For arrays of BIT, BIT_VARYING, or BYTEA values in the source column, run the following query:

    SELECT
  ARRAY(
    SELECT FROM_BASE64(element)
    FROM UNNEST(JSON_VALUE_ARRAY(BQ_COLUMN_NAME, '$')) AS element
  ) AS array_of_bytes

  • For arrays of JSON or JSONB values in the source column, use the JSON_QUERY_ARRAY function:

    SELECT
  ARRAY(
    SELECT element
    FROM UNNEST(JSON_QUERY_ARRAY(BQ_COLUMN_NAME, '$')) AS element
  ) AS array_of_jsons