Dialects

db2md is dialect-aware for discovery and default schemas.

Behaviour matrix

Backend	Database discovery	Default schema
PostgreSQL	pg_database (connectable, non-template)	public when --schema is omitted
MySQL / MariaDB	SHOW DATABASES	current catalog (--schema optional)
SQLite	single file / :memory:	n/a (schema ignored)
Other	current database only	dialect-dependent

System databases (skipped by default)

Use --include-system to keep them.

• PostgreSQL: postgres, template0, template1
• MySQL / MariaDB: mysql, information_schema, performance_schema, sys

Template databases are also filtered in SQL with NOT datistemplate on PostgreSQL.

SQLite notes

• One database per file path; -d / --database does not switch files.
• If you pass a different -d name, db2md logs a warning and still documents the file in the URL.
• Comments and some constraint details depend on what SQLAlchemy’s SQLite inspector exposes.

Permissions

The connecting user needs read access to catalog metadata (table/column/FK/index listings). No write privileges are required.