Data Definition Language (DDL)

Data Definition Language (DDL) statements define and change the structure of your data — virtual databases, schemas, tables, views, indexes, functions and roles. Because Querona virtualizes data, these structures are metadata mapped over the connected sources rather than physical storage; see Materialization for when they are materialized into a backing store.

Create

Statement	Description
CREATE DATABASE	Creates a virtual database over a connection.
CREATE SCHEMA	Creates a schema in a virtual database.
CREATE TABLE	Creates a new table in the virtual database.
CREATE VIRTUAL TABLE	Creates a metadata-only virtual table that maps to a source object without copying data.
CREATE VIEW	Creates a view in the virtual database.
CREATE INDEX	Creates an index on a view.
CREATE FUNCTION	Creates a user-defined function (UDF).
CREATE ROLE	Creates a database role.

Alter

Statement	Description
ALTER TABLE	Adds a column or constraint to a table, or renames it.
ALTER VIEW	Changes the definition of an existing view.
ALTER INDEX	Modifies an existing index.

Drop

Statement	Description
DROP DATABASE	Removes a virtual database.
DROP SCHEMA	Removes a schema.
DROP INDEX	Removes an index from a view.
DROP FUNCTION	Removes a user-defined function.