Abstract: A method and mechanism for reducing the expense of data transmissions and storage between a first node and a second for a remote-mapped query or a query involving a distributed join operation is disclosed. Data prefetching can be utilized to predictably retrieve information. Data redundancy management can be employed to reduce the expense of transmitting and storing redundant data.

Abstract: A system and method is disclosed that allows resources to be shared among multiple entities, but which can appropriately release system resources after the failure or shutdown of the calling entity. In one approach, a monitoring entity is available to check for session failures. If a session failure is detected, the session is identified in a shared list that is accessible to other related entities. The related entities can be configured to piggyback a message to an appropriate node to kill, shutdown, or release resources associated with the failed session. Alternatively, a related entity can be specifically initiated to send a message to the appropriate node to kill, shutdown, or release the resources.

Abstract: An improved method, mechanism, and system for implementing, generating, and maintaining for implementing session pools is disclosed. Disclosed is a method, mechanism, and system for dynamic sizing of session pools, in which the number of sessions in a given session pool or sub-session pool can be dynamically adjusted upwards or downwards. Also disclosed is an approach for customizing a session in a session pool with a specific set of affinities and attributes, in which tags can be associated with the customized sessions. Tagging can be used to identify sessions to deallocate/reallocate to dynamically size the session or sub-session pools.

Abstract: Disclosed are improved methods, systems, and mediums for implementing a dynamic cursor cache. Cached cursors are tagged to facilitate identification and reuse of cursors from a cursor cache. Cursor caches and cursor usage are managed in an integrated and/or coordinated manner between multiple nodes that have related sets of cursors or cursor resources.

Abstract: A method and system for implementing an improved access interface infrastructure is disclosed. In one approach, an access interface methods is directly supported by an application. The directly supported access interface method corresponds to an access interface implementation. Other access interface methods are transparently processed by being converted or mapped into a generic interface format, which is then translated into the directly supported format.

Abstract: Techniques that promote a fault-tolerant patching system are described. According to one such technique, a patching operation is performed in two phases. During the first phase, before the updates specified in the patching operation are actually applied, an attempt is made to backup files, or portions thereof, which are going to be updated by the patching operation. If a failure is detected during the first phase, then the patching operation aborts without proceeding to the second phase. During the second phase, an attempt is made to perform the updates that the patching operation specifies. If a failure is detected during the second phase, then all of the updated files, or portions thereof, are restored; those files or file portions are replaced with their corresponding backed-up copies, which were made during the first phase. The foregoing technique is extensible to a system in which prospectively affected files are distributed among nodes.

Abstract: Techniques for performing a multi-level patching operation are described. According to one such technique, before a particular patch is applied, the data containers that are targeted by the particular patch are identified. A determination is made as to whether any of these target data containers already has been targeted by any previously applied patch. A determination also is made as to whether any other data container that contains (immediately or otherwise) any of the target data containers already has been targeted by any previously applied patch. If any target data container or any other data container that contains a target data container already has been targeted by a previously applied patch, then the particular patch is not applied to the target data containers.

Abstract: Direct memory accessed is used to perform database operations between two or more machines. Data is read from a first buffer located on a first machine. The data was written into the first buffer in response to the data being written into a second buffer at a second machine. In one embodiment, based, at least in part, on whether the data represents a partial read, a determination is made as to whether to transmit, to the second machine, an explicit acknowledgement that the data was read from the first buffer. In another embodiment, based on whether the amount of unacknowledged data received by the first machine from the second machine exceeds a threshold quantity, a determination is made as to whether to transmit, in response to the data being read from the first buffer, any acknowledgement that the data was read from the first buffer.

Abstract: A method and apparatus are provided for providing access to a remotely located nested object in a distributed database system. For example, a first server receives a request to access a complex database object that is not situated at the first server. When this occurs, the first server sends a second request to a second server. When the first server receives data in response to the second request, it detects whether the received data includes a reference to a nested object. If the first server detects a reference to a nested object, the first server modifies the received data by replacing the reference with a virtual reference to the nested object. The first server stores mapping data that associates the virtual reference with the reference and with an associated server, wherein the associated server is capable of resolving the reference. The first server forwards the modified data to the requestor.

Abstract: A method for applying patches to one or more applications is provided. The method includes receiving a patch for a feature where the patch includes applicability requirements. The applicability requirements detail requirements that should be met for the patch to be applied. Usage information for the feature is then determined. For example, it is determined if a feature has been used by a client. The patch is then applied to an application if the usage information meets the applicability requirements for the feature.

Abstract: Various embodiments of the invention provide solutions to allow more efficient management of clustered environments. Merely by way of example, some embodiments provide a framework for the relatively automated management of clusters, including the addition, deletion and/or modification of cluster nodes. In certain embodiments, this framework may be incorporated within a software application that can assist in the configuration of clusters. Other embodiments provide methods of managing clusters and/or their nodes, including, inter alia, methods of establishing and/or implementing such frameworks. Still other embodiments provide systems, including clustered systems, that provide relatively automated cluster management capabilities.

Abstract: Methods, systems, and machine-readable mediums are disclosed for validating a system environment for a software application. In one embodiment, an input file having a plurality of validation tests identifiers identifying validation tests to validate a system environment for an application is read. At least a portion of the validation tests are executed. The results of the validation tests are outputted.

Abstract: A method and apparatus is provided for providing access to a remotely located nested object in a distributed database system. According to one aspect of the invention, a first server receives a request to access a complex database object that is not situated at the first server. The first server translates the request to a remote mapped request, and transmits the remote mapped request to a second server. When the first server receives data in response to the remote mapped request, it detects whether the received data includes a reference to a nested object. If the first server detects a reference to a nested object, the first server modifies the received data by replacing the reference with a virtual reference to the nested object. The first server also stores mapping data that associates the virtual reference with the reference and with an associated server, wherein the associated server is capable of resolving the reference.

Abstract: A data base system coordinates the execution of a distributed transaction in which a set of participant database systems participates, each of the participants executing a subtransaction of the distributed transaction. The participants include at least one database system (“incompatible database system”) that does not follow a two-phase commit followed by the other participant database systems. The distributed transaction is executed as long as operations performed by the incompatible database system for the distributed transaction are read-only operations. To commit the distributed transaction, the incompatible database system aborts the subtransaction it is executing as part of the distributed transaction, while other participant database systems complete the distributed transaction using a two-phase commit to commit their respective subtransactions.

Abstract: Direct memory accessed is used to perform database operations between two or more machines. Data is read from a first buffer located on a first machine. The data was written into the first buffer in response to the data being written into a second buffer at a second machine. In one embodiment, based, at least in part, on whether the data represents a partial read, a determination is made as to whether to transmit, to the second machine, an explicit acknowledgement that the data was read from the first buffer. In another embodiment, based on whether the amount of unacknowledged data received by the first machine from the second machine exceeds a threshold quantity, a determination is made as to whether to transmit, in response to the data being read from the first buffer, any acknowledgement that the data was read from the first buffer.

Abstract: Direct memory accessed is used to perform database operations between two or more machines. A first segment of memory is allocated for a second machine, where at least one of the first machine and second machine is a database server. During performance of a database operation that involves the transfer of data from the second machine to the first machine, data in the first segment of memory is buffered in response to the second machine writing the data to a second segment of memory on the second machine.

Abstract: One embodiment of the present invention provides a system that modifies a function defined within an application programming interface (API) so that the function includes additional code. The system receives an additional code module to be integrated into the function within the API. The system also receives a command to integrate the additional code module into the function. This command is received through a pre-defined function within the API for integrating additional code into functions within the API. In response to the command, the system links the additional code into the function so that the additional code module is executed when the function is called. In one embodiment of the present invention, linking the additional code module into the function involves linking the additional code module as an entry function that is executed at the beginning of the function.

Abstract: An improved method, mechanism, and system for implementing, generating, and maintaining for implementing session pools is disclosed. A session in a session pool can be customized to with a specific set of affinities and attributes. Tags can be associated with the customized sessions. When a later request is made for a session having a set of desired characteristics, the tags can be used to search for and identify a session in the session pool having the requested characteristics. Also disclosed is a method, mechanism, and system for dynamic sizing of session pools.

Abstract: An improved method, mechanism, and system for implementing, generating, and maintaining for implementing session pools is disclosed. Disclosed is a method, mechanism, and system for dynamic sizing of session pools, in which the number of sessions in a given session pool or sub-session pool can be dynamically adjusted upwards or downwards. Also disclosed is an approach for customizing a session in a session pool with a specific set of affinities and attributes, in which tags can be associated with the customized sessions. Tagging can be used to identify sessions to deallocate/reallocate to dynamically size the session or sub-session pools.

Abstract: Disclosed are improved methods, systems, and mediums for implementing a dynamic cursor cache. Cached cursors are tagged to facilitate identification and reuse of cursors from a cursor cache. Cursor caches and cursor usage are managed in an integrated and/or coordinated manner between multiple nodes that have related sets of cursors or cursor resources.