Abstract: An approach for implementing function semantic based partition-wise SQL execution and partition pruning in a data processing system is provided. The system receives a query directed to a range-partitioned table and determines if operation key(s) of the query include function(s) over the table partitioning key(s). If so, the system obtains a set of values corresponding to each partition by evaluating the function(s) on a low bound and/or a high bound table partitioning key value corresponding to the partition. The system may then compare the sets of values corresponding to different partitions and determine whether to aggregate results obtained by executing the query over the partitions based on the comparison. The system may also determine whether to prune any partitions from processing based on a set of correlations between the set of values for each partition and predicate(s) of the query including function(s) over the table partitioning key(s).

Abstract: Techniques are described that are performed by one or more database management system (DBMS) of the plurality of DBMS nodes comprising one or more database servers performing database operations on one or more databases of the DBMS nodes. The techniques describe receiving, at a QC node, a distributed query that specifying a database of a target DBMS node. Without requesting from the target DBMS node a current logical timestamp of the DBMS node, calculating a synchronization timestamp for the distributed query. In one embodiment, the calculation of the synchronization timestamp for the distributed query is based on a current logical timestamp of the QC node and one or more previous logical timestamps of the target DBMS node that were received prior to the receiving the distributed query. The QC node sends a request to the target DBMS node to execute an operation of the query at the target DBMS node based on the synchronization timestamp.

Abstract: An approach for implementing function semantic based partition-wise SQL execution and partition pruning in a data processing system is provided. The system receives a query directed to a range-partitioned table and determines if operation key(s) of the query include function(s) over the table partitioning key(s). If so, the system obtains a set of values corresponding to each partition by evaluating the function(s) on a low bound and/or a high bound table partitioning key value corresponding to the partition. The system may then compare the sets of values corresponding to different partitions and determine whether to aggregate results obtained by executing the query over the partitions based on the comparison. The system may also determine whether to prune any partitions from processing based on a set of correlations between the set of values for each partition and predicate(s) of the query including function(s) over the table partitioning key(s).

Abstract: Techniques are described that are performed by one or more database management system (DBMS) of the plurality of DBMS nodes comprising one or more database servers performing database operations on one or more databases of the DBMS nodes. The techniques describe receiving, at a QC node, a distributed query that specifying a database of a target DBMS node. Without requesting from the target DBMS node a current logical timestamp of the DBMS node, calculating a synchronization timestamp for the distributed query. In one embodiment, the calculation of the synchronization timestamp for the distributed query is based on a current logical timestamp of the QC node and one or more previous logical timestamps of the target DBMS node that were received prior to the receiving the distributed query. The QC node sends a request to the target DBMS node to execute an operation of the query at the target DBMS node based on the synchronization timestamp.

Abstract: A method, system, and computer program product is disclosed for interacting with a client supported by a client-side cache. Embodiments of a method, a system, and a computer program product are disclosed that retrieve a first snapshot, indicating a state of the database after a last database request by the client, associated with the client, determine any number of invalid cached results for the client based on the first snapshot, and transmit the any number of invalid cached results and a second snapshot, an update for the first snapshot.

Abstract: A method, system, and computer program product is disclosed for caching results in a client-side cache. Embodiments of a method, a system, and a computer program product are disclosed that associate a first snapshot of a database with a client that indicates a state of the database after a last database request by the client, and indicate any number of invalid cached results in the client cache for the client based upon the first snapshot. In some embodiments, the method further includes receiving a second snapshot that indicates a state of the database upon receipt of a database server request by the client, and updating the first snapshot with the second snapshot.

Abstract: A method and apparatus for managing sessions across the nodes of a multi-node system is provided. When a session is first initiated on any node of a multi-node system, a global session identifier is assigned to the session. The global session identifier uniquely identifies the session relative to all other sessions managed by the multi-node system. A session monitor may use the global session identifier to collect and store cumulative statistics about the activity of the session, regardless of which node of the multi-node system is currently managing the session, since the global session identifier uniquely identifies the session relative to all other sessions managed by the multi-node system. As a session may be uniquely identified across the lifetime of the session, the session state may be cleaned-up when the session ceases to be maintained, and the activity of the session during its lifetime may be analyzed.

Abstract: A system, method, computer program and system for suspending a result set and continuing from a suspended result set for a cursor is disclosed. The rows from a row source corresponding to the cursor result set are suspended into storage so that when a fetch is requested the data can be sent (continued) from the suspended storage and does not depend on the original cursor row source or session to be available.

Abstract: A system, method, computer program and system for suspending a result set and continuing from a suspended result set for transparent session migration is disclosed. The rows from a row source are suspended into storage, so that after session migration, the client fetches can transparently continue from the suspended result set.

Abstract: A system, method, computer program and system for suspending a result set and continuing from a suspended result set for a scrollable cursor is disclosed. The rows from a row source corresponding to the scrollable cursor result set are suspended into storage so that when a fetch is requested the data can be sent (continued) from the suspended storage and does not depend on the original scrollable cursor row source or session to be available.

Abstract: A method and system for implementing scrollable cursors is described. A multi-tier caching structure is maintained, in which a partial result set is cached at the client computer and a more-complete result set is cached at the server computer. If the cursor is scrolled in either the forward or backward directions, the partial result set cached at the client computer is first checked to see if requested data is present. If so, then the requested data is fetched from the client cache and the current position of the cursor is moved to the appropriate position in the result set. If the requested data is not present in the client cache, then those data items are fetched from the cache at the server computer.

Abstract: A method and system for implementing failover in a computer system is provided. For a failover involving an order-sensitive dataset or application, a mechanism is provided to detect order inconsistencies between a first set of data and a second set of data, in which the first set of data corresponds to a first connection established before the failover and the second set of data corresponds to a second connection established after the failover.