Abstract: Processing of a request is optimized. The request has one or more predicates. A list of the one or more predicates in the request is created and predicates for which an actual cost has not been stored or for which a cost cannot be estimated are pruned from the list. An access path for the each of the predicates is selected. The request is processed using the selected access paths producing one or more actual predicate costs. The one or more actual predicate costs are stored.

Abstract: A method, computer program and computer system for collecting data from one or more data sources, into which data is continuously stored, and for loading the collected data into one or more data targets is disclosed. One or more events are defined and one or more rules are associated with each event. When one of the one or more events occurs, unmarked data is collected from the one or more data sources in accordance with the rules associated with the one event, the collected, unmarked data in the one or more data sources is marked, and the collected data is stored in one or more of the data targets.

Abstract: A continuous dynamic mobile query system including a mobile device is disclosed. The mobile device includes a mobile device memory, a query stored in the mobile device memory, a transmitter for continuously transmitting the query, a receiver for receiving a response, a mobile device output device for displaying the response. The system also includes a location source device for providing the location of the mobile device and a network adapted to receive the query and the location of the mobile device. The system also includes a database management system adapted to receive the query and the location of the mobile device from the network. The database management system is further adapted to execute the query taking into account the location of the mobile device to produce a response and provide the response to the network. The network is further adapted to receive the response from the database management system and transmit the response to the mobile device.

Abstract: A method, computer program and database system for use in analyzing associations in the order of transactions are disclosed. Data is loaded from the transactions into the database system. The data includes an entry for each transaction and the transactions are grouped into groups. The transactions within each group are put into an order. An analysis of the groups of transactions is performed to find associations in the order of the transactions in the groups.

Abstract: A method, system and computer program for mapping business concepts related to the processing of requests on a database system to database system feature settings is disclosed. Rules limit the requests that will be submitted to the database system for processing and establish workload definitions that can be used to map each request submitted to the database system for processing to database feature settings, based on business concepts associated with each request.

Abstract: A method and computer program for reducing the restart time for a parallel application are disclosed. The parallel application includes a plurality of parallel operators. The method includes repeating the following: setting a time interval to a next checkpoint; waiting until the time interval expires; sending checkpoint requests to each of the plurality of parallel operators; and receiving and processing messages from one or more of the plurality of parallel operators. The method also includes receiving a checkpoint. request message on a control data stream, waiting to enter a state suitable for checkpointing, and sending a response message on the control data stream.

Abstract: A method, computer program, and database system are disclosed for executing database queries. The database includes a first table (T1) having a primary key (PK) column and a first correlated value column (CV1) and a second table (T2) having a foreign key (FK) column related to the primary key column of the first table and a second correlated value column (CV2). One implementation of the method includes preparing a database query for execution based at least in part on application of a derived constraint rule (DCR) having the form, (PK=FK)?CV2+C1?CV1?CV2+C2, where C1 and C2 are constants and “?” means “implies,” to produce an execution plan. A frequency of errors due to changes in DCRs is taken into account when preparing the execution plan. The plan is then executed.

Abstract: A method, computer program and system for regulating the workload of a database system as it processes one or more requests are disclosed. The requests are grouped into workload groups and are processed by one or more of a plurality of subsystems within the database system. Each subsystem has resources. The system has resources. The subsystem resources and the system resources are allocated across the workload groups. The method, computer program and system include monitoring, at a subsystem level, the processing of the requests and adjusting the allocation of subsystem resources to workload groups to achieve a subsystem goal and monitoring, at a system level, the processing of the requests and adjusting the allocation of system resources to workload groups to achieve a system goal. The subsystems are arranged in a hierarchical network.

Abstract: Request processing is optimized. The request has elements. The method, computer program and database system includes selecting an access path for the request taking into consideration a stored actual request element cost, processing the request using the selected access path, producing one or more actual request element costs, and storing the one or more actual request element costs.

Abstract: A method and computer program for clustering a string are described. The string includes a plurality of characters. R unique n-grams T1 . . . R are identified in the string. For every unique n-gram TS, if the frequency of TS in a set of n-gram statistics is not greater than a first threshold, the string is associated with a cluster associated with TS. Otherwise, for every other n-gram TV in the string T1 . . . R, except S, if the frequency of n-gram TV is greater than the first threshold, and if the frequency of n-gram pair TS-TV is not greater than a second threshold, the string is associated with a cluster associated with the n-gram pair TS-TV. Otherwise, for every other n-gram TX in the string T1 . . . R, except S and V, the string is associated with a cluster associated with the n-gram triple TS-TV-TX. Otherwise, nothing is done.

Abstract: Methods, computer programs, and database systems for performing a database query to join two or more tables on a condition are disclosed. Each table includes one or more join columns. Each of the join columns includes zero or more join-column values. The method includes excluding join-column values that do not satisfy the condition, using one or more value-count indexes and performing the database query on non-excluded join-column values.

Abstract: A method for processing a trigger are described. The trigger is associated with a subject table in a relational database and defines a triggering statement and one or more triggered actions. The method includes determining that a triggering statement of a trigger will execute on a subject table row of a subject table and requesting a transition table in response to determining that the triggering statement will execute. The transition table includes a transition table row. The transition table row includes a first value associated with the subject table row and a second value associated with the subject table row. The method further includes reading the transition table row from the transition table and identifying a processing unit to receive the transition table row and a triggered action of the trigger. The method also includes transmitting the transition table row and the triggered action to the identified processing unit to be processed.

Abstract: A method, data structure, and database system for synchronizing access to a global resource by a plurality of processes executing on a computer system are disclosed. A global lock is defined for the global resource and a local instantiation of the global lock is defined for each of the plurality of processes that will access the global resource.

Abstract: A method, computer system, and database system for automating a business rule in a database are disclosed. One or more database triggers associated with a business rule state machine are enabled and the business rule state machine is initialized.

Abstract: A method, computer program, and database system are disclosed for storing element-based descriptions of documents in a database. The database system includes one or more nodes. Each of the one or more nodes provides access to one or more of a plurality of CPUs. Each of the one or more CPUs provides access to one or more of a plurality of virtual processes. Each virtual process is configured to manage data stored in one of a plurality of data-storage facilities. The data stored in the plurality of data-storage facilities includes data representing a database table. A row of the table corresponds to an element of the element-based document description and includes: data describing the element, an order identifier corresponding to the element, and a range identifier corresponding to the element.

Abstract: A method, computer program, and database system for controlling operations that may be performed on a user-defined type (UDT) are disclosed. The UDT is derived from an underlying type that has a set of underlying operations. The method includes creating the UDT and activating zero or more underlying operations for the UDT.

Abstract: A computer program and system for redistributing data in a relational data base management system includes storing one or more rows of a database table in an allocated buffer associated with a program. The program is associated with a transmitting processing module and is capable of managing a redistribution of one or more rows associated with one or more database tables. The method includes comparing the allocated buffer to a portion of the buffer to be occupied by the one or more rows. If the allocated buffer is larger than the portion of the buffer to be occupied by the one or more rows, then the method includes communicating a message to one or more destination processing modules, the message comprising at least some of the one or more rows stored in the allocated buffer. Otherwise, the method includes executing a many-rows method to redistribute the one or more rows.

Abstract: In a method, computer program and process for administering the workload of a database system as it executes one or more requests the one or more requests are sorted into one or more workload groups. Each workload group has an associated level of service desired from the database system. The one or more requests are executed in an order intended to achieve the levels of service associated with each of the workload groups. The system resources are assigned to the one or more workload groups as necessary to provide the level of service associated with each workload group. The execution of requests is monitored on a short-term basis to detect a deviation from the level of service greater than a short-term threshold. If such a deviation is detected, the assignment of system resources to workload groups is adjusted to reduce the deviation. Monitoring is also performed on a long-term basis to detect deviations from the expected level of service greater than a long-term threshold.

Abstract: A method, database system, and computer program for collecting statistics about a table are disclosed. The table includes one or more rows and each row includes a respective value. The method includes creating zero or more histogram buckets. Each histogram bucket includes a width representing a respective range of values and a height representing a count of rows having values in the range of values. The method further includes creating one or more high-bias buckets, each high-bias bucket represents one or more values that appear in a minimum percentage of rows.

Abstract: Methods, computer programs, and database systems for analyzing one or more queries are disclosed. Queries may include one or more conditions and one or more sub-queries, with each sub-queries introduced by connecting condition. The method determines the satisfiability of the query, including the satisfiability of the connecting conditions and conditions in the sub-queries. Queries may include one or more conditions of the form (X+Y OP C). The method determines the satisfiability of the query, including the satisfiability of the conditions of the form (X+Y OP C).