Abstract: System and methods for temporary data management in shared disk cluster configurations is described. In one embodiment, a method for managing temporary data storage comprises: creating a global temporary database accessible to all nodes of the cluster on shared storage; creating a local temporary database accessible to only a single node (owner node) of the cluster; providing failure recovery for the global temporary database without providing failure recovery for the local temporary database, so that changes to the global temporary database are transactionally recovered upon failure of a node; binding an application or database login to the local temporary database on the owner node for providing the application with local temporary storage when connected to the owner node; and storing temporary data used by the application or database login in the local temporary database without requiring use of write ahead logging for transactional recovery of the temporary data.

Abstract: System and methods for temporary data management in shared disk cluster configurations is described. In one embodiment, a method for managing temporary data storage comprises: creating a global temporary database accessible to all nodes of the cluster on shared storage; creating a local temporary database accessible to only a single node (owner node) of the cluster; providing failure recovery for the global temporary database without providing failure recovery for the local temporary database, so that changes to the global temporary database are transactionally recovered upon failure of a node; binding an application or database login to the local temporary database on the owner node for providing the application with local temporary storage when connected to the owner node; and storing temporary data used by the application or database login in the local temporary database without requiring use of write ahead logging for transactional recovery of the temporary data.

Abstract: The SQL compiler and SQL executor in a database management system are extended to process queries requiring streaming mode processing of data stored in a table. A scan operator performs table access functions during execution of the streaming mode query. The scan operator first performs an initial scan to access rows in a specified database table, and then performs a delta scan to access new rows added to the table, as well as rows modified by other queries. The scan operator continues to process new data added to the table until the initiating user or application closes the associated cursor. A set of data structures are provided to keep track of active scan operators, including a session control block that includes fields for keeping track of whether the scan operator is performing an initial scan or a delta scan. The session control block also includes, for streaming mode scan operators, a delta scan list of new and modified rows to be processed in the delta scan.

Abstract: The SQL compiler and SQL executor in a database management system are extended to execute statements for dequeuing rows from a database table and statements that both updating tuples and return those tuples to a calling application. During execution of a select statement that includes an embedded update or delete operation, a table access operator accesses a defined range of rows in a database table. The table access operator receives from a calling application a request for rows dequeued from the database table. The table access operator responds to the requests for rows by returning to the calling application qualifying rows, if any, from the database table and also by performing the embedded delete or update operation. The SQL executor returns control to the calling application only after all rows deleted or updated by the table access operator have been sent to the calling application.

Abstract: A database management system includes an execution engine that, upon rollback of an aborted transaction, has the ability to set fields of the rows that are updated or deleted by the transaction prior to aborting. In particular, when a select, update or delete statement includes a “set on rollback” clause, the respective table access operator of the execution engine modifies the “before image” of each row that is stored by the transaction log manager. The modified before image includes the field updates specified by the set on rollback clause. If a transaction associated with the statement aborts, when the transaction log manager restores the before images of each row that was deleted or updated by the transaction, the restored before images include the field updates specified by the set on rollback clause.

Abstract: The SQL compiler and SQL executor in a database management system are extended to process queries requiring streaming mode processing of data stored in a table. A scan operator performs table access functions during execution of the streaming mode query. The scan operator first performs an initial scan to access rows in a specified database table, and then performs a delta scan to access new rows added to the table, as well as rows modified by other queries. The scan operator continues to process new data added to the table until the initiating user or application closes the associated cursor. A set of data structures are provided to keep track of active scan operators, including a session control block that includes fields for keeping track of whether the scan operator is performing an initial scan or a delta scan. The session control block also includes, for streaming mode scan operators, a delta scan list of new and modified rows to be processed in the delta scan.

Abstract: In a database management system, when the table to be accessed by a statement is partitioned, a respective partition scan operator is used to access rows of each respective database table partition. A fan out operator receives requests from a calling application to access rows from table, and responds by sending requests for rows to the partition scan operators. It receives rows of the table from the partition scan operators and sends the received rows of the database table to another node in the execution tree. Each of the partition scan operators responds to the requests for rows by returning to the fan out operator qualifying rows, if any, from the corresponding table partition. If the statement being executed includes an embedded delete or update operation, the qualifying rows are deleted or updated at the same time that the qualifying rows are returned to the fan out operator.

Abstract: The SQL compiler and SQL executor in a database management system are extended to process queries requiring streaming mode processing of data stored in a table. A scan operator performs table access functions during execution of the streaming mode query. The scan operator first performs an initial scan to access rows in a specified database table, and then performs a delta scan to access new rows added to the table, as well as rows modified by other queries. The scan operator continues to process new data added to the table until the initiating user or application closes the associated cursor. A set of data structures are provided to keep track of active scan operators, including a session control block that includes fields for keeping track of whether the scan operator is performing an initial scan or a delta scan. The session control block also includes, for streaming mode scan operators, a delta scan list of new and modified rows to be processed in the delta scan.

Abstract: A database management system is extended to process SQL statements so as to skip over rows that are locked in conflicting modes. Normally, a table access operator is blocked when it attempts to access a row that is locked in a conflicting mode, such as a write lock mode, that is inconsistent with the read or write access required by the operator. Generally, the lock in the conflicting mode will be held by a transaction other than the transaction associated with the operator in question. When the SQL statement being executed uses the “skip conflict” syntax provided by the present invention, the operator skips over rows that are locked in conflicting modes, which would otherwise cause the operator to suspend operation. Furthermore, if the operator is operating in streaming mode, a key that identifies such skipped rows is added to the operator's list of rows to be processed at a later time.