Abstract: A method for committing a distributed transaction in a distributed database system. The database system includes an interval coordinator, a plurality of database server programs, called coservers, and at least one transaction log. More than one coserver can operate on a single computer or node, and the coservers could share a transaction log. The interval coordinator sends each coserver a succession of interval messages, and each coserver flushes its associated transaction log to non-volatile storage in response. After flushing its transaction log, each coserver transmits a closure message to the interval coordinator. The coservers maintain a state which identifies the most recently received interval message. Each distributed transaction includes an owner and a non-owner, or helper. For a transaction, the owner transmits a request message to the helper identifying an operation in the distributed transaction for the coserver to execute.

Abstract: Logical schemas are used to allow an end user the ability to access and manipulate relational database data without knowledge of the structure of the relational database. A logical schema is first created specifying which tables are available to an end user, and the relationships between columns of those tables. The logical schema defines a structure for the data fields having a master level and a plurality of detail levels. An end user may manipulate the logical schema using a graphical interface to build customized forms, reports, and queries. An end user is not required to be familiar with a database query language, such as SQL, or the structure of the relational database.