Abstract: A high availability database can be provided having a plurality of interconnected nodes. Each node can having a processing engine, volatile memory and non-volatile memory. The database can be configured: at a participant node of a transaction performed within the database, to create a record of the transaction; to record a current status of the transaction by storing the record in volatile memory; and to record a long term record of the transaction by storing the record in non-volatile memory. In one example, nodes can be organized into neighbor groups, where each node in the neighbor group maintains a copy of the same data fragments and receives a copy of log records from a primary member of the group.

Abstract: A database server with a "shared nothing" system architecture has multiple nodes, each having its own central processing unit, primary and secondary memory for storing database tables and other data structures, and communication channels for communication with other ones of the nodes. The nodes are divided into at least two groups that share no resources. Each database table in the system is divided into fragments distributed for storage purposes over all the nodes in the system. To ensure continued data availability after a node failure, a "primary replica" and a "standby replica" of each fragment are each stored on nodes in different ones of the groups. Database transactions are performed using the primary fragment replicas, and the standby replicas are updated using transaction log records. Every node of the system includes a data dictionary that stores information indicating where each primary and standby fragment replica is stored.

Abstract: A database server with a "shared nothing" system architecture has multiple nodes, each having its own central processing unit, primary and secondary memory for storing database tables and other data structures, and communication channels for communication with other ones of the nodes. The nodes are divided into first and second groups that share no resources. Each database table in the system is divided into fragments distributed for storage purposes over all the nodes in the system. To ensure continued data availability after a node failure, a "primary replica" and a "standby replica" of each fragment are each stored on nodes in different ones of the first and second groups. Database transactions are performed using the primary fragment replicas, and the standby replicas are updated using transaction log records. Every node of the system includes a data dictionary that stores information indicating where each primary and standby fragment replica is stored.