Abstract: According to an aspect, a database management system (DBMS) is operated to perform data replication. The DBMS includes a source database and a target database. The source database includes a plurality of first tables respectively comprising one or more first columns, and the target database includes a plurality of second tables respectively comprising one or more second columns. Each of multiple ones of the first columns is mapped to one of the second columns, and each one of the second columns is adapted to store replicated data changes of the first column mapped to the second column. Each of the second columns has an assigned update time, the update time being a moment in time when the second column most recently received incremental data changes from its mapped first column. The DBMS operates to process requested database statements while providing data replication.

Abstract: A computer-implemented method for operating a database management system which includes a source database and a target database. A database management system is configured for asynchronously replicating data changes of the source database to the target database. The database management system receiving a request to perform a database statement. The method can identify the most recently committed one of a plurality of transactions having been committed in the source database before the receiving of the request. Identifying repeatedly the one of the plurality of transactions having been replicated most recently to the target database. Execution of the requested statement in the target database is delayed until an evaluation of the repeatedly identified most recently replicated transaction returns that the identified most recently committed transaction has been replicated to the target database. After the delaying execution, the method executes the requested statement in the target database.

Abstract: Embodiments of the present invention provide a system, method and computer program products for memory space management for storage class memory. One embodiment comprises a method for information storage in an information technology environment. The method comprises storing data in a storage class memory (SCM) space, and storing storage management metadata corresponding to said data, in the SCM in a first data structure. The method further includes buffering storage management metadata corresponding to said data, in a main memory in a second data structure.

Abstract: According to one embodiment of the present invention, a method for processing a query in a column database is provided. The method for analyzing test results may include a computer, associating a first set of metadata values with a set of records in a table, wherein each record has an associated state indicated by a metadata value. The method may further include the computer receiving a query to return one or more records of the set of records. The method may further include the computer determining that one or more records in the set of records satisfies the query. The method may further include the computer determining whether at least a first record in the one or more records that satisfies the query is in a returnable state based, at least in part, on the metadata value.

Abstract: According to one embodiment of the present invention, a method for processing a query in a column database is provided. The method for analyzing test results may include a computer, associating a first set of metadata values with a set of records in a table, wherein each record has an associated state indicated by a metadata value. The method may further include the computer receiving a query to return one or more records of the set of records. The method may further include the computer determining that one or more records in the set of records satisfies the query. The method may further include the computer determining whether at least a first record in the one or more records that satisfies the query is in a returnable state based, at least in part, on the metadata value.

Abstract: Embodiments of the present invention provide a system, method and computer program products for memory space management for storage class memory. One embodiment comprises a method for information storage in an information technology environment. The method comprises storing data in a storage class memory (SCM) space, and storing storage management metadata corresponding to said data, in the SCM in a first data structure. The method further includes buffering storage management metadata corresponding to said data, in a main memory in a second data structure.

Abstract: Embodiments relate to database systems. An aspect includes deferring row insert operations until occurrence of a triggering event. One method includes receiving a row insert for a tuple into a column group store table, where the tuple includes one or more tuplets and each of the tuplets corresponds to a column group in the column group store table. The method also includes copying at least one of the tuplets into an insert buffer that is specific to one of the column groups in the column group store table. The method also includes deferring the row insert into the column group store table until an occurrence of one or more triggering events. The method also includes flushing the row insert into storage associated with the column group store table, in response to the occurrence of the one or more triggering events.

Abstract: Provided are techniques for using parallel inserts to insert into a column store. A list of sub-ranges for a columnar table is created. A change statement for one or more rows to be inserted into the columnar table is received. For each of the received change statements, a sub-range from the list of sub-ranges is identified and data is serially inserted into the identified sub-range of the columnar table, while allowing parallel processing of each change statement for different sub-ranges of the columnar table.

Abstract: Provided are techniques for using parallel inserts to insert into a column store. A list of sub-ranges for a columnar table is created. A change statement for one or more rows to be inserted into the columnar table is received. For each of the received change statements, a sub-range from the list of sub-ranges is identified and data is serially inserted into the identified sub-range of the columnar table, while allowing parallel processing of each change statement for different sub-ranges of the columnar table.

Abstract: Embodiments of the present invention provide a system, method and computer program products for memory space management for storage class memory. One embodiment comprises a method for information storage in an information technology environment. The method comprises storing data in a storage class memory (SCM) space, and storing storage management metadata corresponding to said data, in the SCM in a first data structure. The method further includes buffering storage management metadata corresponding to said data, in a main memory in a second data structure.

Abstract: Embodiments of a system are described. In one embodiment, the system is a device for performing operations and supporting transactions. The device is configured to receive a transaction comprising a command and data. The device writes the data to a transaction manager on a persistent memory device. The transaction manager also maintains a status of the transaction and reference to entries within memory that are manipulated by the transaction. The device also creates an in-memory log of the transaction in a first hash directory. The device then commits a copy of the first hash directory to a second hash directory maintained on a persistent memory device.

Abstract: Embodiments of a method are described. In one embodiment, the method is a method for executing and supporting transactions. The method includes receiving a transaction comprising a command and data. The method includes writing the data to a transaction manager on a persistent memory device. The transaction manager also maintains a status of the transaction and reference to entries within memory that are manipulated by the transaction. The method also includes creating an in-memory log of the transaction in a first hash directory. The method includes committing a copy of the first hash directory to a second hash directory maintained on a persistent memory device.

Abstract: Described herein are techniques for supporting bi-temporal data in a key value cache system. An embodiment provides bi-temporal data as the basic functionality of a key value cache system. An embodiment provides a redesign of the core data structures of a key value cache system, adds bi-temporal data storage in the key value hashing structure, and provides a temporality-aware memory space manager. Embodiments can achieve the same performance as current key value cache systems for regular queries (that is, the queries that only access the current versions of data) while supporting bi-temporal data.

Abstract: A computer program product, including: a computer readable storage device to store a computer readable program, wherein the computer readable program, when executed by a processor within a computer, causes the computer to perform operations for logging. The operations include: receiving a transaction including data and a log record corresponding to the data; writing the data to a data storage device; and writing the log record to a log space on a persistent memory device coupled to the data storage device.

Abstract: A local database cache enabling persistent, adaptive caching of either full or partial content of a remote database is provided. Content of tables comprising a local cache database is defined on per-table basis. A table is either: defined declaratively and populated in advance of query execution, or is determined dynamically and asynchronously populated on-demand during query execution. Based on a user input query originally issued against a remote DBMS and referential cache constraints between tables in a local database cache, a Janus query plan, comprising local, remote, and probe query portions is determined. A probe query portion of a Janus query plan is executed to determine whether up-to-date results can be delivered by the execution of a local query portion against a local database cache, or whether it is necessary to retrieve results from a remote database by executing a remote query portion of Janus query plan.

Abstract: A local database cache enabling persistent, adaptive caching of either full or partial content of a remote database is provided. Content of tables comprising a local cache database is defined on per-table basis. A table is either: defined declaratively and populated in advance of query execution, or is determined dynamically and asynchronously populated on-demand during query execution. Based on a user input query originally issued against a remote DBMS and referential cache constraints between tables in a local database cache, a Janus query plan, comprising local, remote, and probe query portions is determined. A probe query portion of a Janus query plan is executed to determine whether up-to-date results can be delivered by the execution of a local query portion against a local database cache, or whether it is necessary to retrieve results from a remote database by executing a remote query portion of Janus query plan.

Abstract: A local database cache enabling persistent, adaptive caching of either full or partial content of a remote database is provided. Content of tables comprising a local cache database is defined on per-table basis. A table is either: defined declaratively and populated in advance of query execution, or is determined dynamically and asynchronously populated on-demand during query execution. Based on a user input query originally issued against a remote DBMS and referential cache constraints between tables in a local database cache, a Janus query plan, comprising local, remote, and probe query portions is determined. A probe query portion of a Janus query plan is executed to determine whether up-to-date results can be delivered by the execution of a local query portion against a local database cache, or whether it is necessary to retrieve results from a remote database by executing a remote query portion of Janus query plan.

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, apparatus, and article of manufacture for maintaining a materialized view derived from at least one base table in a database stored on a computer. An update is performed to the base table in a transaction. Thereafter, the materialized view is accessed to identify affected records therein using at least one mechanism, such as an isolation level or update- and exclusive-locks, to guarantee consistency while avoiding deadlocks with other transactions that modify at least one base table of the materialized view and to improve concurrency with other transactions that are accessing the materialized view when the modification to the base table is applied to the materialized view.

Abstract: In a database system with linkage between data in the database system and files in a system for filing data which is external to the database system (“the filing system”), backup and restoration of the database are coordinated with the filing system. Backup of a referenced file is initiated when the file is linked to the database system. The file backup is asynchronous to the linking process. When database backup occurs, all unfinished file backups are accelerated and completed before the database backup is declared successful. When a database is restored to a state with reference to files in a file manager, the database system causes the file manager to ensure that referenced files are linked to the database system.