Abstract: Validating a query execution includes determining whether a condition of a query has changed and recompiling the query if the condition has changed.

Abstract: A method for modifying an original data object in a database using a single command is disclosed. The single command is first validated. Once the command has been validated a ghost data object is created using the new definition. The ghost data object is populated with data from the original object. The transaction log records from the original data object are applied to the ghost data object. The original data object is then locked for exclusive access. The final transaction log records from the original data object are applied to the ghost data object. In the final step the database switches to the new data object. Dependent objects are automatically transformed as part of the same operation.

Abstract: A method for modifying an original data object in a database using a single command is disclosed. The single command is first validated. Once the command has been validated a ghost data object is created using the new definition. The ghost data object is populated with data from the original object. The transaction log records from the original data object are applied to the ghost data object. The original data object is then locked for exclusive access. The final transaction log records from the original data object are applied to the ghost data object. In the final step the database switches to the new data object. Dependent objects are automatically transformed as part of the same operation.

Abstract: A database computer system includes memory, residing in a plurality of interconnected computer nodes, for storing database tables. Each database table has a plurality of columns, a primary key index based on a specified subset of the columns, and an associated table schema. At least a subset of the database tables are partitioned into a plurality of partitions, each partition storing records having primary key values in a primary key range distinct from the other partitions. A transaction manager generates and stores an audit trail, each audit entry denoting a database table record event, such as an addition, deletion or alteration of a specified database table record in a specified one of said database tables. Four online data definition procedures allow the structure of a database table to be altered while the database table remains available to execution of transactions, with minimal impact of the availability of the database table for transaction execution.