P pulmonale), but have a low predictive value (~20%). A P wave with increased amplitude can indicate hypokalemia. It can also indicate right atrial enlargement. A P wave with decreased amplitude can indicate hyperkalemia. Bifid P waves (known as P mitrale) indicate left-atrial abnormality-e.g. dilatation or hypertrophy.
SYSTEM is a schema..... Technically -- A schema is the set of metadata (data dictionary) used by the database, typically generated using DDL. A schema defines attributes of the database, such as tables, columns, and properties. A database schema is a description of the data in a database.
The star schema is an important special case of the snowflake schema, and is more effective for handling simpler queries. The star schema gets its name from the physical model's resemblance to a star shape with a fact table at its center and the dimension tables surrounding it representing the star's points.