What are the components of the records defined in a schema in a database?

The correct answer highlights the essential elements that make up the records defined in a schema within a database. Each record in a database is structured according to the rules defined by the schema, which specifies the format, types, and relationships of the data.

A schema typically includes various attributes or fields, and each record consists of data entries that correspond to these attributes. A unique index number is often included as part of this structure to facilitate quick access and retrieval of records, ensuring that each entry can be identified distinctly among the dataset. This unique identifier, along with the actual data entries, allows for organized and efficient data management.

The other options describe aspects that are not foundational components of records in a database schema. While unique identifiers for the database and references to external data sources may play a role in managing the data, they do not constitute the direct structure of the records themselves. Moreover, outlines of queries and stored procedures relate to database functionalities for data manipulation and retrieval rather than the fundamental schema that defines how records are formed and structured.