International Business Machines Corporation

Columbia University

Lucent Technologies Inc.

At+t Corp.

Globalfoundries Inc.

Kenneth Andrew Ross

Bishwaranjan Bhattacharjee

Mustafa Canim

Mohammad Sadoghi Hamedani

Divesh Srivastava

Adam J Storm

Yuan-Chi Chang

Daniel Francis Lieuwen

Bassem Makni

Akira Kawaguchi

Inderpal Singh Mumick

George Andrei Mihaila

Christian Alexander Lang

Jun Rao

Sundararajarao Sudarshan

Latha S Colby

Fabian Nagel

Zhe Li

Hui Lei

Dallan Wendell Quass

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.

Preplaying transactions that mix hot and cold data

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.

Supporting transient snapshot with coordinated/uncoordinated commit protocol

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.

Access frequency approximation for remote direct memory access

Staging data record changes from a faster storage medium to a slower storage medium using data query rewriting is provided. In response to receiving a data query corresponding to a particular data record, it is determined whether the data query is one of a transactional data query or an analytical data query. In response to determining that the data query is a transactional data query, the transactional data query is rewritten to apply transactional delta changes to the particular data record on a storage-class memory of a computer. In response to determining that the data query is an analytical data query, the analytical data query is rewritten to select and reconcile each data record corresponding to the particular data record stored on the storage-class memory with the particular data record stored on a persistent data storage device of the computer.

Deferring data record changes using query rewriting

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.

Adaptive concurrency control using hardware transactional memory and locking mechanism

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.

Reducing database locking contention using multi-version data record concurrency control

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.

Compressing a multi-version database

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.

Method and system for automatic space organization in tier2 solid state drive (SSD) cache in databases for multi page support

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.

Managing a multi-version database

A system and method for managing a cache includes monitoring a temperature of regions on a secondary storage based on a cumulative cost to access pages from each region of the secondary storage. Similar temperature pages are grouped in logical blocks. Data is written to a cache in a logical block granularity by overwriting cooler blocks with hotter blocks.

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Kenneth Andrew Ross