Abstract: One or more usage models are provided for a database. Each usage model includes a set of rules that are used to analyze database performance. A usage model in one or more usage models is determined. Database information is determined based on the usage model. The database information is then analyzed based on rules associated with the usage model. One or more performance problems are determined based on the analysis.

Abstract: A self-managing workload repository (AWR) infrastructure useful for a database server to collect and manage selected sets of important system performance statistics. Based on a schedule, the AWR runs automatically to collect data about the operation of the database system, and stores the data that it captures into the database. The AWR is advantageously designed to be lightweight and to self manage its use of storage space so as to avoid ending up with a repository of performance data that is larger than the database that it is capturing data about. The AWR is configured to automatically capture snapshots of statistics data on a periodic basis as well as purge stale data on a periodic basis. Both the frequency of the statistics data capture and length of time for which data is kept is adjustable. Manual snapshots and purging may also be performed. The AWR captured data allows for both system level and user level analysis to be automatically performed without unduly impacting system performance, e.g.

Abstract: A method for receiving a database query language statement and performance information about the statement at an optimizer and generating one or more tuning actions for the statement with the performance information is disclosed.

Abstract: Systems and methods to define and store performance baselines. A baseline may be defined as a pair of snapshots, each snapshot containing the same set of statistics and having a timestamp value associated therewith. The present invention allows for the designation, automatically or manually, of statistics collected over a certain period of time to be stored and used for comparison. Baselines may be used, for example, to manually or automatically compare with current system performance, compare difference-difference values and set thresholds to monitor current system performance.

Abstract: An intelligent database infrastructure wherein the management of all database components is performed by and within the database itself by integrating management of various components with a central management control. Each individual database component, as well as the central management control, is self-managing. A central management control module integrates and interacts with the various database components. The database is configured to automatically tune to varying workloads and configurations, correct or alert about bad conditions, and advise on ways to improve overall system performance.

Abstract: One or more usage models are provided for a database. Each usage model includes a set of rules that are used to analyze database performance. A usage model in one or more usage models is determined. Database information is determined based on the usage model. The database information is then analyzed based on rules associated with the usage model. One or more performance problems are determined based on the analysis.

Abstract: Systems and methods to define and store performance baselines. A baseline may be defined as a pair of snapshots, each snapshot containing the same set of statistics and having a timestamp value associated therewith. The present invention allows for the designation, automatically or manually, of statistics collected over a certain period of time to be stored and used for comparison. Baselines may be used, for example, to manually or automatically compare with current system performance, compare difference-difference values and set thresholds to monitor current system performance.

Abstract: An intelligent database infrastructure wherein the management of all database components is performed by and within the database itself by integrating management of various components with a central management control. Each individual database component, as well as the central management control, is self-managing. A central management control module integrates and interacts with the various database components. The database is configured to automatically tune to varying workloads and configurations, correct or alert about bad conditions, and advise on ways to improve overall system performance.

Abstract: A self-managing workload repository (AWR) infrastructure useful for a database server to collect and manage selected sets of important system performance statistics. Based on a schedule, the AWR runs automatically to collect data about the operation of the database system, and stores the data that it captures into the database. The AWR is advantageously designed to be lightweight and to self manage its use of storage space so as to avoid ending up with a repository of performance data that is larger than the database that it is capturing data about. The AWR is configured to automatically capture snapshots of statistics data on a periodic basis as well as purge stale data on a periodic basis. Both the frequency of the statistics data capture and length of time for which data is kept is adjustable. Manual snapshots and purging may also be performed. The AWR captured data allows for both system level and user level analysis to be automatically performed without unduly impacting system performance, e.g.

Abstract: An approach for recovering after premature termination of a plurality of transactions involves: A) selecting a previously unselected transaction from the plurality of transactions; B) processing the selected transaction by undoing the lesser of a predetermined number of changes made by the selected transaction and all changes made by the selected transaction; and C) repeating steps A) and B) until all of the plurality of transactions have been processed. Another aspect of the approach involves: A) selecting a previously unselected transaction from the plurality of transactions, wherein the selected transaction is the previously unselected transaction from the plurality of transactions that made the fewest number of changes in the database; B) processing the selected transaction by undoing one or more changes in the database made by the selected transaction; and C) repeating steps A) and B) until all transactions from the plurality of transactions have been processed.

Abstract: A method and apparatus manage shared resources in a multiprocessing computer system. A coordinator process identifies resources to be operated upon by a plurality of worker processes. The coordinator process acquires locks to lock the resources on behalf of the plurality of worker processes. The plurality of worker processes then operate on the resources locked by the coordinator process.

Abstract: A method and apparatus for parallelizing operations that change a database is provided. A coordinator process receives a statement that requires data to be written into the database. In response to the statement, the coordinator process assigns granules of work to multiple processes. Each of the multiple processes executes the granule of work by writing to the database a distinct portion of the set of data that is to be added to the database. The various portions of data are then merged to update the set of data to be added to the database.

Abstract: A method for managing termination of a process that holds a resource lock on behalf of another process is described. A first process acquires a first lock to a resource on behalf of a second process to exclude other processes from accessing the resource. The second process then acquires a wait lock to the resource. Later, when a third process acquires the first lock to the resource, the third process determines whether the first process terminated without releasing the lock. If the first process did terminate without releasing the lock, the third process attempts to acquire the wait lock. In attempting to acquire the wait lock, execution of the third process is suspended until the second process releases the wait lock. Consequently, acquisition of the wait lock by the third process prevents concurrent access to the resource by the third process and the second process.

Abstract: A method and system for recovering after a crash of an instance in a database is disclosed. According to the method, transaction information corresponding to all the transactions that existed in the failed instance is inspected. These transactions that were active at the time the instance crashed are marked as "dead." The database is made available to users after updating the transaction information and before undoing all of the changes or updates performed by dead transactions. The changes made by the dead transactions may be undone by new transactions on a on-demand basis after the database is made available. Specifically, when a new transaction is waiting to obtain a lock on a resource held by another transaction, the new transaction determines whether the owner of the lock is one of the dead transactions. If so, the new transaction rolls back some or all of the changes made by the dead transaction.

Abstract: A method and apparatus for recovering an object that includes logged data and a set of non-logged data is provided. According to the method, a copy of the object resides in volatile memory. A change is made to the copy of the object. If the change does not change any data within the object other than the non-logged data, then the change is made to the copy of the object without generating redo information. If the change changes any data within the object other than the non-logged data, then redo information is generated in response to the change. The redo information is stored on non-volatile storage. After a failure, the redo information is used to restore all data within the object other than the non-logged data. The non-logged data may be restored by retrieving the non-logged data from a different object for which redo information was generated for the non-logged data. A description of how this technique may be used to efficiently perform selective non-deferred block cleanout is also provided.