Finally, persistent classes have zero memory overhead.
There are no hidden "database" members that each class must have nor are there per-object data structures allocated by ODB.
ODB has been designed for high performance and low memory overhead.
Prepared statements are used to send and receive object state in binary format instead of text which reduces the load on the application and the database server.
As such, this document is intended for C application developers and software architects who are looking for a C object persistence solution.
Prior experience with C is required to understand this document.
It provides tools, APIs, and library support that allow you to persist C objects to a relational database (RDBMS) without having to deal with tables, columns, or SQL and without manually writing any of the mapping code. It can either completely hide the relational nature of the underlying database or expose some of the details as required.
For example, you can automatically map basic C types to suitable SQL types, generate the relational database schema for your persistent classes, and use simple, safe, and yet powerful object query language instead of SQL.
From the application developer's perspective, ODB consists of three main components: the ODB compiler, the common runtime library, called .
A basic understanding of relational database systems is advantageous but not expected or required.
Beyond this manual, you may also find the following sources of information useful: ODB is an object-relational mapping (ORM) system for C .
Or you can assign SQL types to individual data members, use the existing database schema, run native SQL a convenient way to handle results of native SQL queries. It does not dictate how you should write your application.
Rather, it is designed to fit into your style and architecture by only handling object persistence and not interfering with any other functionality.
For each input header file the ODB compiler generates a set of C source files implementing conversion between persistent C classes defined in this header and their database representation.