
How to Write Performant Queries
Query.make() is the heart of all database queries. Queries are made against entities (e.g. .eti, .etx) which are complex database objects. xCenter uses an Object Relational Mapper (ORM) to retrieve and save all data from the Database Management System (DBMS). By using an ORM, the query logic remains DBMS agnostic, so it does not matter if we are using MS SQL, Oracle, DB2 or H2, the query language is abstracted away from us. Most of the SQL produced by the ORM is ANSI SQL with some exceptions for specific DBMS implementations.