Overview

This section describes how you can migrate data to DLI in an efficient way. You can use Cloud Data Migration Service (CDM) to migrate data from other cloud services or platforms to DLI.

DLI is a serverless data processing and analysis service. It processes streaming data and batch data and supports interactive analysis. Its high-scalability framework supports the convergence of batch and streaming data analysis, and provides real-time, efficient, and diversified compute resources for TB-to EB-level data processing.

Best Practices of Data Migration

You can migrate Hive data to DLI. For details, see Migrating Data from Hive to DLI.
You can migrate Kafka data to DLI. For details, see Migrating Data from MRS Kafka to DLI.
You can migrate Elasticsearch data to DLI. For details, see Migrating Data from Elasticsearch to DLI.
You can migrate RDS data to DLI. For details, see Migrating Data from RDS to DLI.
You can migrate GaussDB(DWS) data to DLI. For details, see Migrating Data from GaussDB(DWS) to DLI.

Data Type Mapping

If you migrate data from other cloud services or platforms to DLI, data types need to be converted and source and destination data must be mapped by type. Table 1 lists the mapping relationships.

**Table 1** Data type mapping
MySQL	Hive	GaussDB(DWS)	Oracle	PostgreSQL	Hologres	DLI Spark
CHAR	CHAR	CHAR	CHAR	CHAR	CHAR	CHAR
VARCHAR	VARCHAR	VARCHAR	VARCHAR	VARCHAR	VARCHAR	VARCHAR/STRING
DECIMAL	DECIMAL	NUMERIC	NUMERIC	NUMERIC	DECIMAL	DECIMAL
INT	INT	INTEGER	NUMBER	INTEGER	INTEGER	INT
BIGINT	BIGINT	BIGINT	NUMBER	BIGINT	BIGINT	BIGINT/LONG
TINYINT	TINYINT	SMALLINT	NUMBER	SMALLINT	SMALLINT	TINYINT
SMALLINT	SMALLINT	SMALLINT	NUMBER	SMALLINT	SMALLINT	SMALLINT/SHORT
BINARY	BINARY	BYTEA	RAW	BYTEA	BYTEA	BINARY
VARBINARY	BINARY	BYTEA	RAW	BYTEA	BYTEA	BINARY
FLOAT	FLOAT	FLOAT4	FLOAT	DOUBLE	FLOAT4	FLOAT
DOUBLE	DOUBLE	FLOAT8	FLOAT	REAL/DOUBLE	FLOAT8	DOUBLE
DATE	DATE	TIMESTAMP	DATE	DATE	DATE	DATE
TIME	Not supported (use String instead)	TIME	DATE	TIME	TIME	Not supported (use String instead)
DATETIME	TIMESTAMP	TIMESTAMP	TIME	TIME	TIMESTAMP	TIMESTAMP
TINYINT	TINYINT	BOOLEAN	Not supported	TINYINT	BOOLEAN	BOOLEAN
Not supported (use TEXT instead)	Not supported (use String instead)	Not supported (use TEXT instead)	Not supported (use VARCHAR instead)	Not supported (use TEXT instead)	Not supported (use TEXT instead)	ARRAY
Not supported (use TEXT instead)	Not supported (use String instead)	Not supported (use TEXT instead)	Not supported (use VARCHAR instead)	Not supported (use TEXT instead)	Not supported (use TEXT instead)	MAP
Not supported (use TEXT instead)	Not supported (use String instead)	Not supported (use TEXT instead)	Not supported (use VARCHAR instead)	Not supported (use TEXT instead)	Not supported (use TEXT instead)	STRUCT