Table Structure Conversion

Overview

DBConvert Streams provides automatic table structure conversion between different database types, enabling seamless heterogeneous data migration. When you create a stream with createStructure: true, the system automatically:

1. Analyzes source table structures
2. Maps data types between source and target databases
3. Creates corresponding tables in the target database
4. Sets up appropriate indexes and constraints

Supported Conversions

Current database type conversion paths:

• MySQL → PostgreSQL
• PostgreSQL → MySQL
• MariaDB → PostgreSQL
• PostgreSQL → MariaDB

Data Type Mapping

DBConvert Streams automatically maps data types between databases using the following principles:

MySQL to PostgreSQL

MySQL Type	PostgreSQL Type
TINYINT	SMALLINT
SMALLINT	SMALLINT
MEDIUMINT	INTEGER
INT/INTEGER	INTEGER
BIGINT	BIGINT
FLOAT	REAL
DOUBLE	DOUBLE PRECISION
DECIMAL	NUMERIC
CHAR	CHAR
VARCHAR	VARCHAR
TEXT	TEXT
DATETIME	TIMESTAMP
TIMESTAMP	TIMESTAMP
DATE	DATE
TIME	TIME
BOOLEAN/TINYINT(1)	BOOLEAN
JSON	JSONB

PostgreSQL to MySQL

PostgreSQL Type	MySQL Type
SMALLINT	SMALLINT
INTEGER	INT
BIGINT	BIGINT
REAL	FLOAT
DOUBLE PRECISION	DOUBLE
NUMERIC/DECIMAL	DECIMAL
CHAR	CHAR
VARCHAR	VARCHAR
TEXT	TEXT
TIMESTAMP	DATETIME
DATE	DATE
TIME	TIME
BOOLEAN	TINYINT(1)
JSONB/JSON	JSON

Configuration

Example : Skipping Index Creation

{
    "name": "skip_indexes_stream",
    "source": "conn_source",
    "target": "conn_target",
    "mode": "convert",
    "createStructure": true,
    "tables": [
        {
            "name": "large_table"
        }
    ],
    "target": {
        "options": {
            "tables": [
                {
                    "name": "large_table",
                    "noCreateIndexes": true
                }
            ]
        }
    }
}

Available target options:

• createStructure: Create table structure on target
• noCreateIndexes: Skip index creation for specified tables
• schema: Specify target schema (PostgreSQL only)

Primary Keys and Indexes

By default, DBConvert Streams:

1. Preserves primary key definitions
2. Creates corresponding indexes in the target database
3. Maintains foreign key relationships when possible

To skip index creation for specific tables, use the noCreateIndexes option.

Related Documentation

• Stream Configuration Guide
• MySQL Writer Configuration
• PostgreSQL Writer Configuration