Abstract: Methods, computer program products, and systems are presented. The method computer program products, and systems can include, for instance: examining data of breaches of a geofence by client computer devices to determine respective positions of the breaches; receiving by a database system transaction data from client computer devices, the transaction data defined by insert query data; changing a structure of an index of a certain table of the database system in response to the receiving; generating logging data in response to the receiving of the transaction data; providing using the logging data prediction specifying data, the prediction specifying data specifying one or more change predicted to occur with respect to the index; and modifying the index in dependence on the prediction specifying data.

Abstract: Methods, computer program products, and systems are presented. The method computer program products, and systems can include, for instance: examining data of breaches of a geofence by client computer devices to determine respective positions of the breaches; receiving by a database system transaction data from client computer devices, the transaction data defined by insert query data; changing a structure of an index of a certain table of the database system in response to the receiving; generating logging data in response to the receiving of the transaction data; providing using the logging data prediction specifying data, the prediction specifying data specifying one or more change predicted to occur with respect to the index; and modifying the index in dependence on the prediction specifying data.

Abstract: A shared memory device called the Coupling Facility (CF) is used to record the indoubt transaction entries for each member of the database cluster, avoiding the CPU cost and elapsed time impact of persisting this information to disk (either via a log write or a relational table I/O). The CF provides full read/write access and data coherency for concurrent access by all the members in the database cluster. At any given point in time, the CF will contain the full list of indoubt transactions for the entire database cluster. CF duplexing is used to guarantee the integrity of the CF structure used for the indoubt list. In the event of complete loss of both CF structures (which will not happen except in major disaster situations), data sharing group restart processing can reconstruct the CF structures from the individual member logs.

Abstract: A partial index availability system places, in a restricted state, all pages in the index associated with a structure modification, when an error occurs in processing a log of the said structure modification. This maintains traversability of the rest of the index that is not in restricted state. The system locates and marks a left sentinel and a right sentinel associated with a non-leaf page that is in a restricted state preventing an undo of a transaction. The sentinels prevent a transaction from accessing an uncommitted change associated with the non-leaf page. After a recovery procedure is run the entire index is made available. During the period between the placement of the index pages in LPL or rebuild pending to the time of final removal of these pages from their restrictive states as a result of a recovery procedure being run, the users are given access to the non-restricted portion of the index.

Abstract: A system, method a computer usable storage medium tangibly embodying a program of instructions executable by the computer to perform a computer-based method for restoration of a database from a failed data recovery. For each failed data recovery the method generates a log error data set having log records of a faulty transaction unapplied to data due to inconsistency. Log error data set is directly useable by a log analysis tool to regenerate and redo the unapplied faulty transaction to recover the data and by a print log tool to diagnose the faulty transaction. Log records mimic format of records of an archive log data set and identify data objects, faulty transactions on the data objects and a range of the unapplied data objects' updates.

Abstract: A method for performing a system level backup of a log-ahead database management system (DBMS) without suspending updates by application programs is described. The DBMS comprises a database mainline system, a backup utility and a restore utility. The data and log records are stored on separate storage volumes. Log records are written to identify objects that require special handling during the point-in-time recovery. The database engine operates normally during a backup except for suspending actions that would alter the file system catalog or write updates across a storage volume boundary; and by freezing the REDO log point in its checkpoint information. The backup utility copies the data volumes first and optionally the log volumes second while updates are allowed. The resulting inconsistencies are resolved either during a DBMS restart or during a point-in-time (PIT) recovery performed by the restore utility.

Abstract: A shared memory device called the Coupling Facility (CF) is used to record the indoubt transaction entries for each member of the database cluster, avoiding the CPU cost and elapsed time impact of persisting this information to disk (either via a log write or a relational table I/O). The CF provides full read/write access and data coherency for concurrent access by all the members in the database cluster. At any given point in time, the CF will contain the full list of indoubt transactions for the entire database cluster. CF duplexing is used to guarantee the integrity of the CF structure used for the indoubt list. In the event of complete loss of both CF structures (which will not happen except in major disaster situations), data sharing group restart processing can reconstruct the CF structures from the individual member logs.

Abstract: Disclosed is a system, method, and program for transferring data. When a transaction commits, multiple data objects that have been changed by the transaction are identified. The multiple data objects are written from local storage to a cache structure using a batch write command. When changed data objects at a first system that are not cached in the shared external storage are written to disk, a batch cross invalidation command is used to invalidate the data objects at a second system. Additionally, multiple data objects are read from the cache structure into a processor storage using a batch castout command.

Abstract: A system, computer usable medium and computer-based method for altering a sequence number assignment pattern while preserving integrity and high concurrency in an environment having a plurality of applications on at least one computer system sharing a direct access storage device (DASD). The method generates and assigns sequence numbers for a shared sequence object located on the shared DASD to a plurality of applications executing concurrently and using the shared sequence object. When an application starts altering the shared sequence object attribute(s) during concurrent assignment of sequence numbers by other applications, it notifies all computer systems using the shared sequence object to locally refresh the sequence object attribute descriptor and discard unused reserved sequence numbers, and then updates the altered shared sequence object attribute and last assigned sequence number on the shared DASD.

Abstract: A method, apparatus, article of manufacture, and data structure for use in efficiently generating sequence numbers in a multi-system data-sharing environment. Sequence number assignment logic, performed by a computer system, generates a recoverable, unique sequence number for assignment to an application, wherein the sequence number is contained in a control page stored in a database on a data storage device coupled to the computer system and shared with other computer systems, and updates to the control page are serialized across all of the computer systems.

Abstract: A method, apparatus, article of manufacture, and data structure for use in providing transaction control for a computer-implemented database management system. The database management system manages one or more databases. A transaction processing system provides transaction control for one or more of the databases managed by the database management system, wherein the transaction processing system assigns a recoverable, unique sequence number whenever a request is made by an application.

Abstract: A method for performing a system level backup of a log-ahead database management system (DBMS) without suspending updates by application programs is described. The DBMS comprises a database mainline system, a backup utility and a restore utility. The data and log records are stored on separate storage volumes. Log records are written to identify objects that require special handling during the point-in-time recovery. The database engine operates normally during a backup except for suspending actions that would alter the file system catalog or write updates across a storage volume boundary; and by freezing the REDO log point in its checkpoint information. The backup utility copies the data volumes first and optionally the log volumes second while updates are allowed. The resulting inconsistencies are resolved either during a DBMS restart or during a point-in-time (PIT) recovery performed by the restore utility.

Abstract: A system, computer usable medium and computer-based method for altering a sequence number assignment pattern while preserving integrity and high concurrency in an environment having a plurality of applications on at least one computer system sharing a direct access storage device (DASD). The method generates and assigns sequence numbers for a shared sequence object located on the shared DASD to a plurality of applications executing concurrently and using the shared sequence object. When an application starts altering the shared sequence object attribute(s) during concurrent assignment of sequence numbers by other applications, it notifies all computer systems using the shared sequence object to locally refresh the sequence object attribute descriptor and discard unused reserved sequence numbers, and then updates the altered shared sequence object attribute and last assigned sequence number on the shared DASD.

Abstract: Disclosed is a system, method, and program for transferring data. When a transaction commits, multiple data objects that have been changed by the transaction are identified. The multiple data objects are written from local storage to a cache structure using a batch write command. When changed data objects at a first system that are not cached in the shared external storage are written to disk, a batch cross invalidation command is used to invalidate the data objects at a second system. Additionally, multiple data objects are read from the cache structure into a processor storage using a batch castout command.

Abstract: A method, apparatus and article of manufacture for ensuring cache coherency in a database containing a data store on a central data storage device connected to a plurality of computers. When an immediate write option is set, the data in a local buffer pool changed by a first transaction on a first computer is immediately written to a group buffer pool at the central data storage device, prior to initiating a second transaction upon a second computer that relies upon the modified data. Local buffer pools are then invalidated thereby facilitating local buffer pool updates from the group buffer pool. The immediate write (IW) option may be a subsystem parameter set at a system level or a bind option set at a plan level. The immediate write option may be set so that data is written to the group buffer pool at or before a phase one commit.

Abstract: A computer-implemented method for minimizing the amount of time to access current data in a database which may be stored wholly in a DASD-oriented external storage subsystem or partly in DASD and partly in a stored high-speed electronic store while maintaining coherency of the data with respect to multiple user systems.