Abstract: A design structure is described for dynamically aligning clocks in independent clock domains with minimal latency. In the preferred embodiments, a reference clock in the destination clock domain that is some multiple times the data clock of the destination clock domain is used to sample a data sample signal from the source domain. The sampled data is used to determine at what time slice of the reference clock the data sample signal is changing and therefore at what phase of time slice or phase of the data clock the clocks can be aligned to ensure valid data will be transferred between clock domains.

Abstract: A computer program communicates with a partition manager in the logical partition where the computer program is run. When resource allocation in the logical partition dynamically changes, the partition manager notifies the computer program of the configuration change. The computer program may autonomically adjust one or more configuration settings that affect performance of the computer program to dynamically tune the computer program to optimal performance each time the allocation of resources within the logical partition changes. The partition manager may notify the computer program of an impending change in resource allocation in the logical partition that runs the computer program, which allows the computer program to reconfigure its configuration setting(s) before the partition manager changes the resource allocation in the logical partition.

Abstract: A global key control mechanism provides a single point of overall control for key generation, but portions of the key generation and/or allocation tasks may be delegated to client computer systems, thereby reducing network traffic. The global key control mechanism may download a client key generation mechanism on one or more client computer systems, and may allocate a block of keys to the client key generation mechanism. Requests for keys may then be routed to the client key generation mechanism, which can generate and/or allocate keys within the block of keys that the global key control mechanism allocated to it. When the block of keys is used up, the client key generation mechanism may request another block from the global key control mechanism. The preferred embodiments also include the capability of downloading a client key generation mechanism with an associated block of keys once the requests from one or more client applications exceed a predetermined threshold.

Abstract: A deterministic UDF processing mechanism processes user-defined functions (UDFs) using multiple hash tables. Data access patterns for a UDF are collected, and an appropriate hash table set is then determined for the UDF from the data access patterns. If a UDF accesses some similar columns and some disjoint columns, the similar columns are grouped together, and one or more hash tables are allocated to the similar columns. Disjoint columns are allocated their own hash tables. In addition, the allocation of hash tables may be adjusted based on historical access patterns collected over time. By dynamically allocating and adjusting sets of hash tables to a deterministic UDF, the performance of the UDF is greatly increased.

Abstract: An apparatus and program product monitors performance of a computer system via a result size including a result set size of accesses to a database and a page size. Preferred embodiments are directed to a performance monitor that correlates data from existing tools that report data concerning access to the database and the use of system resources. Other embodiments are directed to a performance monitor that is included in an application server associated with the database.

Abstract: An apparatus and method allows processing sequenced records across multiple network connections. A “logical connection” is defined to include one or more network connections. Each message is assigned a sequence number that allows the messages to be ordered on the other end according to sequence number, regardless of which network connection in the logical connection is used to transfer the message. By defining messages, sequencing those messages, and transferring the messages over multiple network connections, the throughput and performance of networked computer systems are substantially increased.

Abstract: A minimized journaling mechanism stores minimized journal data in a format that allows for display and outputting the journal data in human-readable form. When a change to a record occurs, instead of writing only the changed bytes, all of the bytes in each field that changed are written to the journal, along with all of the bytes in each field selected to be always journaled. A default object is created with default data in all of the fields. When the journal entry needs to be output in human-readable form, the default object is read, and the minimized journal entry is then overlaid on the default object. The result is an object that contains default data in all non-selected fields that were not changed, with the journal data in all fields and that did change and in all fields that were selected to always be journaled.

Abstract: An apparatus and program product monitor performance of a computer system via a result size including a result set size of accesses to a database and a page size. Preferred embodiments are directed to a performance monitor that correlates data from existing tools that report data concerning access to the database and the use of system resources. Other embodiments are directed to a performance monitor that is included in an application server associated with the database.

Abstract: A partition migration mechanism migrates a logical partition executing an operating system and resumes the logical partition before all resources in the logical partition have been migrated. When a partition is being migrated, a call checkpoint mechanism creates checkpoints of the state of the operating system when the partition manager is called. Before performing the call to the partition manager, a check is made to determine if all resources required by the call are available. If so, the partition manager call is executed. If all resources required by the call are not available, a resource fault is indicated, which causes the operating system state from the last checkpoint to be restored and a corresponding virtual CPU to be preempted until the resource that caused the fault becomes available. Exceptions that do not require the missing resource may be performed while the virtual CPU awaits the resource to become available.

Abstract: In a clustered computer system with multiple power domains, a bus number manager within each power domain manages multiple nodes independently of other power domains. A node within a specified power domain includes a non-volatile memory that includes bus numbering information for its own buses as well as bus numbering information for two of its logically-interconnected neighbors. This creates a distributed database of the interconnection topology for each power domain. Because a node contains bus numbering information about its logical neighbor node(s), the bus numbers for the buses in the nodes are made persistent across numerous different system reconfigurations. The clustered computer system also includes a bus number manager that reads the non-volatile memories in the nodes during initial program load (i.e.

Abstract: A database query optimizer creates a main access plan for a query, and also creates one or more subplans for the same query. The subplans are used in executing a query. When a subplan is generated, all tautological predicates (i.e., predicates that do not narrow the query) are dropped, thereby enhancing the reusability of stored subplans. When a query is processed, its tautological predicates are dropped, and if a subplan for the query with the dropped tautological predicates is found, the subplan is used to execute the query. If the query to be run has no main access plan in the cache, a main access plan is generated, and a subplan is also generated that corresponds to the query to be run, with all tautological predicates dropped. The same query may thus generate many subplans, enhancing the reusability of the query by storing each subplan in the access plan cache.

Abstract: According to the preferred embodiments, a database relationship constraint is defined for a first column that specifies a set of allowable values for the first column that depend on a set of data values in a second column that may be of a different type than data in the first column. In a first embodiment, a database relationship constraint specifies allowable values for one column in a database table based on one or more data values in a different column in the same database table. In a second embodiment, a database relationship constraint specifies a set of allowable values in a first column based on one or more data values in a second column in a different database table. In both cases, the data in the second column may be of a different type than data in the second column.

Abstract: An apparatus and method for a graphical user interface allow performing operations simply by dragging a first object to touch a second object. The selection of the first object places a corresponding first object in a chain of objects. When the selected first object touches a second object, a corresponding second object is added to the chain of objects. This process may continue for the selection of many objects by merely touching each object with the selected first object, which causes a corresponding object to be added to the chain of objects. The chain of objects may then be processed as an atomic group of operations that may be rolled back if any of the operations in the group fail.

Abstract: An apparatus and method provide parallel installation of logical partitions on a computer system. The function of a hardware maintenance console is built into a logical partition configuration mechanism that resides in the system firmware. A virtual local area network (VLAN) is used by the logical partition configuration mechanism to define an I/O bridge that allows installing multiple logical partitions in parallel. Because multiple logical partitions may be installed in parallel, the time required to install logical partitions is greatly reduced.

Abstract: An apparatus and method for a multi-partition query governor in a partitioned computer database system. In preferred embodiments a query governor uses data of a query governor file that is associated with multiple partitions to determines how the query governor manages access to the database across multiple partitions. Also, in preferred embodiments, the query governor in a local partition that receives a query request communicates with a query governor in a target partition to accumulate the total resource demands of the query on the local and target partitions. In preferred embodiments, a query governor estimates whether resources to execute a query will exceed a threshold over all or a combination of database partitions.

Abstract: A method and apparatus for a scalable property viewer for a massively parallel computer system. The property viewer includes a graphical user interface to allow the user to view different properties of the computer system with several different types of views. The different views provide the user with both logical and graphical representations of the properties being monitored and allows the user to link between a logical and physical view of the system. The GUI provides the user with a convenient way to view the elements of a large system and determine elements that are different. Different properties could be placed together in the same view with different colors to allow the user to see the interaction of multiple properties.

Abstract: An apparatus and method for monitoring the performance of a computer system via an result size including a result set size of accesses to a database and a page size. Preferred embodiments are directed to a performance monitor that correlates data from existing tools that report data concerning access to the database and the use of system resources. Other embodiments are directed to a performance monitor that is included in an application server associated with the database.

Abstract: A method and apparatus improves the block allocation time in a parallel computer system. A pre-load controller pre-loads blocks of hardware in a supercomputer cluster in anticipation of demand from a user application. In the preferred embodiments the pre-load controller determines when to pre-load the compute nodes and the block size to allocate the nodes based on pre-set parameters and previous use of the computer system. Further, in preferred embodiments each block of compute nodes in the parallel computer system has a stored hardware status to indicate whether the block is being pre-loaded, or already has been pre-loaded. In preferred embodiments, the hardware status is stored in a database connected to the computer's control system. In other embodiments, the compute nodes are remote computers in a distributed computer system.

Abstract: An apparatus and method for sharing a resource (such as a modem or virtual private network) allow virtualizing the shared resource in a simple and efficient manner that allows both accepting and initiating virtual or physical connections through the shared resource across logical partitions or systems. An L2TP tunnel is established between the server that owns the shared resource and the client that desires to use the shared resource. Messages are defined that allow the client to initiate an outgoing connection through the shared resource, and that allow the client to accept an incoming connection received from the shared resource. Once the connection is made, the client and ultimate destination communicate through the shared resource via point-to-point communications.

Abstract: A debugger display groups threads according to user-specified criteria. The threads may be grouped by type, by current or historic breakpoints, according to historical debug patterns, based on what thread spawned the thread, based on execution pattern, based on object class in a Java environment, based on Java thread group in a Java environment, or base on other suitable criteria. The grouping of threads is displayed graphically to a user of the debugger, thereby allowing more efficient debugging of multi-threaded computer programs.