# SQL Reference The FDB relational subproject provides a SQL API for interacting with Record Layer databases. This SQL API is currently under active development and is expected to change frequently. This reference is currently also a work in progress to be updated as the SQL engine develops. ```{toctree} :caption: SQL :maxdepth: 2 reference/sql_types reference/sql_commands reference/Functions ``` ```{toctree} :caption: Data Model :maxdepth: 2 reference/Databases_Schemas_SchemaTemplates reference/Tables reference/Indexes ``` ```{toctree} :caption: Miscellaneous :maxdepth: 2 reference/Direct_Access_Api reference/understanding_bitmap ```