Abstract: A method includes the following steps. Runtime statistics related to data transaction processing in a concurrent system are collected. A given request to access shared data in the concurrent system is receive. Based on the collected runtime statistics, the number of reattempts the given request can make to access the shared data prior to access control being switched from a hardware transactional memory to a locking mechanism is adaptively determined.

Abstract: A method includes the following steps. One or more records are accessed from a database memory bypassing a database access mechanism of a database system. Data representing access frequency of the one or more records are collected. The collected access frequency data for the one or more records are maintained. The access frequency data for the one or more records are aggregated until the access frequency reaches a threshold value. The aggregated access frequency data are asynchronously reported for the one or more records to the database system.

Abstract: A method includes the following steps. Runtime statistics related to data transaction processing in a concurrent system are collected. A given request to access shared data in the concurrent system is receive. Based on the collected runtime statistics, the number of reattempts the given request can make to access the shared data prior to access control being switched from a hardware transactional memory to a locking mechanism is adaptively determined.

Abstract: A method includes the following steps. Runtime statistics related to data transaction processing in a concurrent system are collected. A given request to access shared data in the concurrent system is receive. Based on the collected runtime statistics, the number of reattempts the given request can make to access the shared data prior to access control being switched from a hardware transactional memory to a locking mechanism is adaptively determined.

Abstract: Atomically updating shared data in a transactional memory system comprising transactional memory storage and a transactional memory enabled processor. The computer creates a pointer stored in a stable memory location that is used to locate a shared data stored in a second memory location. The computer accesses the shared data and loads the pointer used to locate the accessed shared data into transactional memory storage. The computer updates the accessed shared data using copy-on-write, whereby the updated shared data is stored in a third memory location, and performs the atomic update of the shared data by updating the pointer such that it locates the updated shared data stored in the third memory location.

Abstract: Atomically updating shared data in a transactional memory system comprising transactional memory storage and a transactional memory enabled processor. The computer creates a pointer stored in a stable memory location that is used to locate a shared data stored in a second memory location. The computer accesses the shared data and loads the pointer used to locate the accessed shared data into transactional memory storage. The computer updates the accessed shared data using copy-on-write, whereby the updated shared data is stored in a third memory location, and performs the atomic update of the shared data by updating the pointer such that it locates the updated shared data stored in the third memory location.

Abstract: In an approach for supporting queries for hash-based data structures, a processor creates an ordered set of seeds, wherein the ordered set of seeds are a subset of values in a key domain. A processor links each hashed key of a plurality of hashed keys to at least another hashed key of the plurality of hashed keys using the ordered set of seeds, wherein the ordered set of seeds allows retrieval access to data located in the hash-based data structure.

Abstract: A concurrent transaction validate phase with the transaction operations read, compute, and write allows for a rendezvous-based optimistic concurrency control process.

Abstract: Managing a multi-version data record database is provided. A mapping is maintained between a logical record identifier and committed and uncommitted physical record identifiers corresponding to data records using an indirection mapping table. Entries are updated within an index to point to the logical record identifier instead of the committed and uncommitted physical record identifiers. The committed physical record identifier corresponding to a data record is read from the indirection mapping table to access a committed version of the data record while a writer is modifying the data record to prevent the writer from blocking a reader. An uncommitted physical record identifier corresponding to the data record is written in the indirection mapping table to insert a new uncommitted version of the data record within a data table while the reader is reading the committed version of the particular data record to prevent the reader from blocking the writer.

Abstract: Methods and a system are provided. A method includes maintaining an in-page log for records in each of a plurality of data pages of a multi-version database. The method further includes adding record update information to the in-page log when a corresponding one of the records is deleted or updated. The method also includes consulting the in-page log for a recently updated one of the records or a recently deleted one of the records to determine a record status thereof. The method additionally includes spilling, by a processor-based overflow manager, to overflow pages when the in-page log is full. The data pages include any of row-oriented data pages and column-oriented data pages.

Abstract: Methods and a system are provided. A method includes maintaining an in-page log for records in each of a plurality of data pages of a multi-version database. The method further includes adding record update information to the in-page log when a corresponding one of the records is deleted or updated. The method also includes consulting the in-page log for a recently updated one of the records or a recently deleted one of the records to determine a record status thereof. The method additionally includes spilling, by a processor-based overflow manager, to overflow pages when the in-page log is full. The data pages include any of row-oriented data pages and column-oriented data pages.

Abstract: Managing a multi-version database is provided. A logical record identifier to physical record row identifier indirection mapping table on a solid-state storage device is extended to include a plurality of delta blocks. A delta block within the plurality of delta blocks is maintained for each primary key in a plurality of primary keys associated with a data table on a magnetic hard disk storage device.

Abstract: A method for searching the top-K simple shortest paths between a specified source node and a specified target node in a graph, with graph data partitioned and distributed across a plurality of computing servers, the method including a parallel path search initialized from either one or both of the source and target nodes and traversing the graph by building likely path sequences for a match. Each computing server determines and forwards a path sequence as discovery progresses until the top-K paths are discovered.

Abstract: A system and method for adjusting space allocated for different page sizes on a recording medium includes dividing the recording medium into multiple blocks such that a block size of the multiple blocks supports a largest page size, and such that each of the multiple blocks is used for a single page size, and assigning an incoming page to a block based on a temperature of the incoming page.

Abstract: Large graph data in many application domains dynamically changes with vertices and edges inserted and deleted over time. The problem of identifying and maintaining densely connected regions in the graph thus becomes a challenge. Embodiments of the invention describe a method using a k-core measure as a metric of dense connectivity over large, partitioned graph data stored in multiple computing servers in a cluster. The method describes steps to identify a k-core subgraph in parallel and to maintain a k-core subgraph when a new edge is inserted or an existing edge is deleted. The embodiments thus enable practitioners to identify and monitor large scale graph data, such as exemplified by multiple topical communities in a social network, in a scalable and efficient manner.

Abstract: Managing a multi-version database is provided. A logical record identifier to physical record row identifier indirection mapping table on a solid-state storage device is extended to include a plurality of delta blocks. A delta block within the plurality of delta blocks is maintained for each primary key in a plurality of primary keys associated with a data table on a magnetic hard disk storage device.

Abstract: Managing different versions of a data record is provided. A mapping is maintained between a version-independent logical record identifier and a version-dependent physical record row identifier that correspond to each data record within a plurality of data records of a data table using a logical record identifier to physical record row identifier indirection mapping table. Entries within leaf pages of an index associated with the data table are updated to point to the version-independent logical record identifier corresponding to a data record instead of pointing to the version-dependent physical record row identifier corresponding to the data record. The logical record identifier to physical record row identifier indirection mapping table is updated in response to performing an operation on the data record instead of updating the entries within the leaf pages of the index associated with the data table.

Abstract: A method for searching the top-K simple shortest paths between a specified source node and a specified target node in a graph, with graph data partitioned and distributed across a plurality of computing servers, the method including a parallel path search initialized from either one or both of the source and target nodes and traversing the graph by building likely path sequences for a match. Each computing server determines and forwards a path sequence as discovery progresses until the top-K paths are discovered.

Abstract: A method, information processing system, and computer program storage product optimize the placement of database objects on a multiplicity of storage devices. A set of database objects are placed on a first storage device in a multiplicity of storage devices. Each storage device comprises differing characteristics. A query workload is run on the set of database objects that have been placed on the first storage device. Profiling information associated with the query workload that is running is collected. A subset of database objects is selected from the set of the database objects to be stored on a second storage device. The subset of database objects is stored on the second storage device and all remaining database objects in the set of database objects on the first storage device.

Abstract: Methods and systems for performing database transactions include executing a first transaction request in a preplay mode that locks the requested data with a prefetch-lock and reads one or more requested data items from storage into a main memory buffer; locking the requested data items with a read/write lock after said data items are read into the main memory buffer; and performing the requested transaction on the data items in the main memory buffer using a processor.