NexusDB

The Server layer is the core of NexusDB and provides transactional data storage and retrieval services. The two main components of this layer are: TnxServerEngine and TnxSQLEngine.  Other auxiliary components of this layer are responsible for monitoring server engine activity, providing security and logging events.

The Server Engine provides session, database and cursor support. The Server Engine contains object instances for each opened table and a cursor for each client.

Each table object uses the particular sub-engines that are registered for that table as specified in the data dictionary. These sub-engines communicate with the Buffer Manager to store and retrieve the data.  The buffer manager provides transactional support for storage and retrieval of this data.

The SQL Engine parses SQL queries and interacts with the Server Engine to execute those requests.  The SQL Engine supports DML, DDL of the ANSI standard.  The specific SQL grammar supported is detailed in the SQL Reference chapter.