Abstract: A query is received. Based on statistics for a database, a first query access plan is generated for executing the query on the database. A first result set for the query is obtained by implementing the first query access plan on the database. Based on at least one trend in the statistics, a target time after which implementing the first query access plan will fail a set of criteria is forecasted. In response to the forecasting and based on the statistics, a replacement query access plan is generated prior to the target time. After the target time, a second result set for the query is obtained by implementing the replacement query access plan rather than the first query access plan.

Abstract: Method, system, and computer program product are provided to guarantee no tuple loss and/or corruption in a real-time data streaming environment. In some embodiments, a stream of tuples is sent from an entry operator to downstream operator(s), and, at the entry operator, a mark is placed on each tuple in the stream of tuples. In an embodiment where the stream of tuples includes first, second, and subsequent tuple(s), for example, the mark may comprise a tuple-unique number and a tuple-data hash of data contained in the tuple, and the mark on the second and each subsequent tuple may further comprise a link-back hash associated with the immediately preceding tuple in the stream of tuples. In some embodiments, the link-back hash is used to check whether a tuple is lost or received out of order, and the tuple-data hash is used to check whether a received tuple is corrupt.

Abstract: A computer-implemented method for determining a query execution plan based on transaction state may include determining that a first set of database values in a database table are in a committed transaction state and that a second set of database values in the database table are in an uncommitted transaction state. In response to the determining, the first set of database values may have a first set of statistics generated and the second set of database values may have a second set of statistics generated. The first and second set of statistics may be for use in determining a query execution plan.

Abstract: Disclosed aspects relate to query plan management associated with a shared pool of configurable computing resources. A query, which relates to a set of data located on the shared pool of configurable computing resources, is detected. A virtual machine includes the set of data. With respect to the virtual machine, a set of burden values of performing a set of asset actions is determined. Based on the set of burden values, a query plan to access the set of data is established. Using at least one asset action of the set of asset actions, the query plan is processed.

Abstract: A streams manager includes a connection converter that allows converting at run-time a static connection to a dynamic connection, and converting at run-time a dynamic connection to a static connection. One or more conversion criteria are defined that determine when a conversion of one or more connections is needed at run-time. When conversion criteria for converting a static connection from a first processing element to a second processing element to a dynamic connection is satisfied, the first processing element interacts with the streams manager and with the second processing element to dynamically change the static connection to a dynamic connection. When conversion criteria for converting a dynamic connection from a first processing element to a second processing element to a static connection is satisfied, the first processing element interacts with the streams manager and with the second processing element to dynamically change the dynamic connection to a static connection.

Abstract: Disclosed aspects relate to transforming a user-defined table function (UDTF) to a derived table in a database management system (DBMS). It may be detected by the DBMS that a query indicates the UDTF. A derived table may be constructed from the UDTF. The derived table may be derived from a set of statements of the UDTF. The derived table may be introduced to the query to fulfill the UDTF. A query plan may be generated for the query by the DBMS. The query plan may be generated in response to introducing the derived table in the query.

Abstract: An index shared between a plurality of tables is used to access a data sharing space (DSS) storing a set of rows from a base table having a plurality of rows with stored data. First data values of the index are identified in response to a query for a table. A subset of rows is then retrieved from the DSS using the index elements corresponding to the first data values. Second data values and some of the first data values are then identified in response to a second query for a table. A second subset of rows are then retrieved from the DSS using the index elements corresponding to the second data values and some of the first data values and the query is then applied to the subset of rows.

Abstract: A computer system can generate a materialized query table (MQT) for data from a base table that has a plurality of rows and columns that each contain stored data. The computer system can receive a query to data stored in a row from the base table. The system can identify a column in the row and determine that data from a cell in the row and the column is above a threshold memory size. The system can generate, in response to determining that the data being above the threshold memory size, an MQT that includes data for the row and that includes a reference pointer that points to a location shared with another table.

Abstract: Method, system, and computer program product are provided to guarantee no tuple loss and/or corruption in a real-time data streaming environment. In some embodiments, a stream of tuples is sent from an entry operator to downstream operator(s), and, at the entry operator, a mark is placed on each tuple in the stream of tuples. In an embodiment where the stream of tuples includes first, second, and subsequent tuple(s), for example, the mark may comprise a tuple-unique number and a tuple-data hash of data contained in the tuple, and the mark on the second and each subsequent tuple may further comprise a link-back hash associated with the immediately preceding tuple in the stream of tuples. In some embodiments, the link-back hash is used to check whether a tuple is lost or received out of order, and the tuple-data hash is used to check whether a received tuple is corrupt.

Abstract: A tuple manager of a database system processes partial tuples from a streaming application and stores them in a database. The partial tuples may include a large object (LOB) that arrives at the database at a different time than the rest of the corresponding tuple. A tuple manager stores partial tuples and uses a partial tuples index to track the partial tuples and coordinate recombination of corresponding partial tuples. The database allows queries to be run on the partial data before the tuples are reconstructed allowing faster access to potentially important data before the arrival and processing of a partial tuple such as an LOB.

Abstract: System, method, and computer program product to perform an operation comprising determining that a sort sequence of a query specifying to access data in a first column of a shared weight object based on a first selection predicate applied to the first column does not match a sort sequence of the shared weight object, adding a second selection predicate to the query based on the sort sequence of the first selection predicate and the shared weight sort sequence of the first column of the shared weight object, and executing the query by using the second selection predicate as a key selection against the first column in the shared weight object to return a result set, wherein the result set does not include a shared weight data value of a first row of the first column that would have been returned using the shared weight object to process the query.

Abstract: Dynamic connections between processing elements of a streaming application are managed in a distributed manner by the processing elements to increase efficiency and performance of real-time connection updates. A streams application management service includes a connection manager that notifies all processing elements when a job with a new processing element is submitted. Each processing element dynamically maintains its own connections based on one or more of the following conditions: connection data received from the streams management service, and a behavior change of the processing element. Then the processing element reports connection updates to the connection manager in the streams management service. The connection manager may store updated connection information in the connection data.

Abstract: A sequence object manager provides a sequence object with a dynamic cache block size that indicates a block size of values to be added to the sequence object when the cache values are exhausted. The dynamic block size allows the sequence object manager to optimize performance and storage space depending on applications using the sequence object. The dynamically block size is set and maintained by the sequence object manager based on observed performance and historical trends of the applications. A seed value may be provided by the user to initially set the dynamic block size.

Abstract: A journal optimizer in a computer database system with an adaptive journal mechanism. The adaptive journal mechanism dynamically adjusts adaptive parameters of the journal optimizer to optimize the journal based on one or more journal conditions to more efficiently utilize system resources. The adaptive parameters used to adapt the optimization include aggressiveness parameters and the location of the optimizer, where the aggressiveness parameters specify the intensity of optimization of the journal by the journal optimizer. For example, the adaptive journal mechanism may dynamically adjust an adaptive parameter of the optimizer to increase optimization of the journal when the resource utilization indicates the resources are underutilized and decrease optimization of the journal when the resource utilization indicates resources are strained.

Abstract: A journal optimizer in a computer database system with an adaptive journal mechanism. The adaptive journal mechanism dynamically adjusts adaptive parameters of the journal optimizer to optimize the journal based on one or more journal conditions to more efficiently utilize system resources. The adaptive parameters used to adapt the optimization include aggressiveness parameters and the location of the optimizer, where the aggressiveness parameters specify the intensity of optimization of the journal by the journal optimizer. For example, the adaptive journal mechanism may dynamically adjust an adaptive parameter of the optimizer to increase optimization of the journal when the resource utilization indicates the resources are underutilized and decrease optimization of the journal when the resource utilization indicates resources are strained.

Abstract: Disclosed aspects relate to transforming a user-defined table function (UDTF) to a derived table in a database management system (DBMS). It may be detected by the DBMS that a query indicates the UDTF. A derived table may be constructed from the UDTF. The derived table may be derived from a set of statements of the UDTF. The derived table may be introduced to the query to fulfill the UDTF. A query plan may be generated for the query by the DBMS. The query plan may be generated in response to introducing the derived table in the query.

Abstract: A structured query language (SQL) query is configured to present a selected portion of a result set to a user interface. The selected portion of the result set can be based on an offset criteria appended to the SQL query. The offset criteria determines a location of a first presented instance of the selected portion of the result set. The offset criteria is configured to determine the location of the first presented instance of the selected portion of the result set independent of a number of instances appearing between a first instance of the result set and the first presented instance of the selected portion of the result set.

Abstract: Systems, methods, and computer program products to perform an operation comprising receiving, by a database management system (DBMS) from an application, a request specifying to generate a global temporary table (GTT) of a first format, identifying a first GTT, of a plurality of GTTs stored by the DBMS, that has a second format, different than the first format, modifying the first GTT such that at least a portion of the modified first GTT is of the first format, and providing the modified first GTT to the application.

Abstract: Disclosed aspects relate to transforming a user-defined table function (UDTF) to a derived table in a database management system (DBMS). It may be detected by the DBMS that a query indicates the UDTF. A derived table may be constructed from the UDTF. The derived table may be derived from a set of statements of the UDTF. The derived table may be introduced to the query to fulfill the UDTF. A query plan may be generated for the query by the DBMS. The query plan may be generated in response to introducing the derived table in the query.

Abstract: A public operator processes data streams from multiple operators in different streaming applications to reduce resource costs and increase efficiency in a streaming system. The public operator uses tuple level security with a unique key for each streaming application to securely process the data streams. A stream security module (SSM) manages encryption to and from the public operators to insure other streaming applications with access to the shared public operator don't have access to data of other applications that may belong to other customers or users. The stream security module may be incorporated into the streams manager of a streaming system.