# Generated API

> The database schema identifies the database, defines each data class, its elements, its relationship to other data classes, and data access methods. When compiled with the eXtremeDB DDL compiler produces two files, `<DatabaseName>.h`, and `<DatabaseName>.c`, which contain the structure (typedef) definitions and specific functions generated for each of the DDL elements. The generated functions will have names that are prefixed with dbname_ (the database name), classname_, classname_indexname_, classname_fieldname_ or structname_fieldname depending on the type of function. Many of the generated functions will have an argument of type class handle which is simply a typedef classname.

> Please use the links below to view the functions by category:

> Database | Database level functions
> Class | Class related functions
> Index | Index related functions
> Field | Field access functions
> Event | Event functions
> Top | The top function, one of the most popular queries against time series data is to locate the top N performing instruments