Db* ..... open source database management.

Db.*, is an open source database solution for database management that supports the use of both the relational and network database models.

In the relational model, data is stored in tables, composed of columns and rows. Data in separate tables are related through common columns. A join operation is used to access related data in separate tables using the common column(s). While the relational model is easy to use and flexible, performance is limited by the need to create new tables to hold results from relational operations, and storage requirements are increased because redundant columns are stored in related tables. Join processing is normally done through an index that consumes system resources and requires the storage and maintenance of index files.

In the network model, relationships are defined between records using "sets", where pointers are used to relate records directly. Compared to the relational model, the network model is faster (one can find a related record in a single logical disk access instead of three or more with a relational model), more reliable (pointers to "member' records are maintained directly in the "owner' record), more efficient (disk space is saved when sets are used since no indexes are required), and better at expressing real life complexity. Combined Database Models

Since db.

* supports both models, you can optimize your schema by using relational design where it is most efficient and network design where it is most effective. For real performance, one could use an index to access records that require fast random or sorted access, while information that falls naturally into one-to-many relationships can be organized into sets.

db.

* gives users low-level control over the database. Database manipulation and control are performed through calls to C language functions contained in the db.

* runtime library. The functions contained in the library control all database operations such as opening/closing databases, creating and modifying records and fields, and connecting/disconnecting sets. This low-level control makes it possible to define exactly how data is to be accessed, allowing opimization.

IT also supports multiple users. A back ground lock manager program provides currency control and fast processing of lock requests. the lock manager cm reside on any node: no dedicated server is required.

db.

* lets users take advantage of transactions. A transaction is a group of related database updates is written as a unit first to a log file (to support recovery), then to the database. This helps to insure database integrity, even if the system is unexpectedly stopped.