DDL (Data Definition Language) Commands

These topics provide reference information for the DDL (Data Definition Language) commands in Databend.

Database & Table Management

Component	Description
Database	Create, alter, and drop databases
Table	Create, alter, and manage tables
View	Create and manage virtual tables based on queries
Dictionary	Create key-value lookup tables for data enrichment

Performance & Indexing

Component	Description
Cluster Key	Define data clustering for query optimization
Aggregating Index	Pre-compute aggregations for faster queries
Inverted Index	Full-text search index for text columns
Ngram Index	Substring search index for LIKE patterns
Virtual Column	Extract and index JSON fields as virtual columns

Security & Access Control

Component	Description
User	Create and manage database users
Network Policy	Control network access to databases
Mask Policy	Apply data masking for sensitive information
Password Policy	Enforce password requirements and rotation

Data Integration & Processing

Component	Description
Stage	Define storage locations for data loading
Stream	Capture and process data changes
Task	Schedule and automate SQL operations
Sequence	Generate unique sequential numbers
Connection	Configure external data source connections
File Format	Define formats for data import/export

Functions & Procedures

Component	Description
UDF	Create custom functions in Python or JavaScript
External Function	Integrate external APIs as SQL functions
Procedure	Create stored procedures for complex logic
Notification	Set up event notifications and webhooks

Resource Management

Component	Description
Warehouse	Manage compute resources for query execution
Workload Group	Control resource allocation and priorities
Transaction	Manage database transactions
Variable	Set and use session/global variables