Database migration often starts with a familiar question: How much of our existing SQL can we keep?
GBase Database (GBase 8c) takes a multi-mode compatibility approach, supporting Oracle, PostgreSQL, and MySQL SQL dialects through a single distributed database kernel.
Instead of maintaining three separate database engines, GBase Database provides different compatibility modes while keeping its underlying execution, transaction, storage, and distributed capabilities native.
How Triple-Mode Compatibility Works
The architecture can be viewed in three layers.
1. Mode-Aware Parser
The parser identifies the selected SQL dialect and converts dialect-specific syntax into a common internal representation.
This allows developers to work with familiar SQL while the underlying engine maintains a consistent execution model.
2. Function Compatibility Layer
Common functions and expressions are mapped according to the selected compatibility mode.
For example, function equivalents such as NVL and COALESCE can be handled through the compatibility layer, reducing the amount of application-side rewriting required during migration.
3. Native Database Engine
Below the compatibility layer is the GBase Database kernel itself.
Distribution, transaction processing, storage, query execution, and other core database capabilities are implemented natively rather than inherited from Oracle, PostgreSQL, or MySQL.
This distinction matters: SQL compatibility does not mean the database behaves exactly like the original system.
What Developers Should Expect
Triple-mode compatibility can simplify migration, but it does not eliminate testing.
Common SQL:
Many standard statements and frequently used dialect features can be migrated with limited changes.
Deep ecosystem features:
Extensions and ecosystem-specific components, such as PostgreSQL plugins, may require separate evaluation or adaptation.
Application consistency:
Although applications can use different compatibility modes, choosing one primary mode per project generally makes development and maintenance easier.
Performance behavior:
Locking, query planning, execution strategies, and storage behavior ultimately follow GBase Database semantics. Existing SQL should therefore be tested under realistic workloads rather than assuming identical performance.
Why Triple-Mode Compatibility Matters
For migration projects, compatibility is more than a checklist item. It can reduce the distance between an existing application and a new database platform.
A team coming from Oracle, PostgreSQL, or MySQL can start with a familiar SQL environment while taking advantage of the distributed architecture of GBase Database (GBase 8c).
The key idea is simple:
Meet developers where their SQL already lives, while providing a native database engine underneath.
For any migration, however, compatibility should be validated across SQL syntax, interfaces, database objects, tools, and application behavior—not just basic queries.
How important is SQL compatibility when your team evaluates a new distributed database?
