公开(公告)号：CA2427071C

公开(公告)日：2010-07-06

申请号：CA2427071

申请日：2003-04-28

Applicant: IBM CANADA

Inventor： CRANSTON LESLIE A ,  BHATTACHARJEE BISHWARANJAN ,  HURAS MATTHEW A ,  LINDSAY BRUCE G ,  MALKEMUS TIMOTHY R ,  MCARTHUR CATHERINE S ,  PADMANABHAN SRIRAM K ,  WINER MICHAEL J

IPC: G06F16/22

Abstract: An information retrieval system and method of operation therefor, wherein a plurality of dimensions for a table are identified, and at least one block in a plurality of blocks in the table is associated with a dimension value for each dimension in the plurality of dimensions, where each block comprises a plurality of contiguous storage pages. Additionally, the at least one block can be further associated with an associated cell, wherein the associated cell has a unique combination of dimension values comprising an associated dimension value for each dimension in the plurality of dimensions. A unique associated bit list for each dimension value for each dimension in the plurality of dimensions has a unique corresponding list entry for each block associated with that dimension value, and a unique associated bit list for each cell has a unique corresponding list entry for each block associated with that cell. These unique associated bit lists facilitate searching, insertion and deletion of records. Each list entry in the unique associated bit lists may also have an associated storage space indicia bit for its associated block for indicating whether the block is likely to be full for further facilitating insertion of records and management of data storage space. Each block may also have a unique associated empty page bitmap for indicating when pages in the block are empty and for identifying when the entire block is empty so that the block may be disassociated from its associated dimension values and associated cell.

公开(公告)号：CA2281287C

公开(公告)日：2003-03-11

申请号：CA2281287

申请日：1999-09-01

Applicant: IBM CANADA

Inventor： HOP HING NELSON ,  WINER MICHAEL J ,  HURAS MATTHEW A ,  LINDSAY BRUCE G ,  CRANSTON LESLIE A

IPC: G06F17/30

Abstract: A method of searching a table in a database management system for free space for inserting a new record into the table. The table resides in a storage media, and includes a series of pages capable of storing a plurality of records. The table has a clustering index defined in a column of the table. The new record has a new record attribute for storing in the column o f the table when the new record is stored in the table. The method comprises searching for a target page in the series of pages, the target page being selected to maintain clustering when the new record is inserted thereon. Once the target page has been located, it is searched for sufficient free space t o accommodate the new record. If sufficient free space is found on the target page, then the new record is inserted on the target page. If sufficient free space is not found on the target page, then a target neighbourhood of pages in the series of pages is searched for sufficient free space to accommodate the new record. The target neighbourhood of pages surrounds the target page. If sufficient free space is found on a page in a target neighbourhood of pages, then the new record is inserted on to this page in the target neighbourhood of pages. If sufficient free space is not found in the target neighbourhood of pages, then the methodfurther comprises searching for sufficient free space to accommodate the new record outside the target neighbourhood of pages. If sufficient free space is found outside the target neighbourhood of pages, then the new record is inserted on a non-neighbourin g page outside the target neighbourhood of pages. If sufficient free space is not found outside the target neighbourhood of pages, then a new page having the new record is appended to the end of table.

公开(公告)号：CA2369621C

公开(公告)日：2009-06-09

申请号：CA2369621

申请日：2002-01-25

Applicant: IBM CANADA

Inventor： WINER MICHAEL J ,  ZHENG ROGER L Q ,  HURAS MATTHEW A ,  GOSS JEFFREY J ,  FLASZA MIROSLAW A ,  POSNER SARAH ,  MEADOWCROFT LORYSA M ,  MCARTHUR CATHERINE S

IPC: G06F9/50 ,  G06F9/46 ,  G06F12/00 ,  G06F12/14 ,  G06F13/14 ,  G06F17/30

Abstract: The present invention is directed at a method and apparatus for handling resource transaction requests. By marking a waiting transaction request, having an access mode which is incompatible with the access mode of at least one of the executing transactions, with an ignore bit, a subsequent transaction request with an access mode compatible with the access mode(s) o f the executing transaction(s) may receive access to the resource. The subsequent transactio n request is then marked with a bypass indicator such that when the executing transactions are finish ed accessing the resource, the waiting transaction request may be notified it may have access to the resource. By including the ignore bit, each subsequent transaction request which arrives after ignore b it has been set, does not suffer from starvation.

公开(公告)号：CA2322603C

公开(公告)日：2005-04-12

申请号：CA2322603

申请日：2000-10-06

Applicant: IBM CANADA

Inventor： HURAS MATTHEW A ,  WINER MICHAEL J ,  GORALWALLA IQBAL A ,  SHARPE DAVID C

IPC: G06F17/30 ,  G06F12/02 ,  G06F9/312

Abstract: An optimization for updatable scrollable cursors in database systems. To ensure that a temporary copy of a data record matches the data record maintained in the database, th e temporary copy is associated with a timestamp included on each page storing the data records o f the database. The timestamp on a page in the database is updated whenever any record stored on the page is updated. The optimization compares the timestamp stored with the temporary record wit h the current timestamp associated with the page on which the data record is stored in the database. If the two timestamps are matching then the temporary record is identical to the databa se table record and there is no need to carry out a comparison of the attribute values of the temporar y record with the record in the database table.

公开(公告)号：CA2249080A1

公开(公告)日：2000-03-25

申请号：CA2249080

申请日：1998-09-25

Applicant: IBM CANADA

Inventor： WINER MICHAEL J ,  HOP HING NELSON ,  HURAS MATTHEW A ,  LINDSAY BRUCE G ,  ROMANUFA KERILEY K ,  GOSS JEFFREY J

IPC: G06F17/30

Abstract: A method for efficiently searching free space in a relational database management system. The method limits the search to a finite number of space map pages in the free space map. If the configured number of space map pages in the free space map are searched and a page with free space is not found for the row, the row is inserted on the last page, or if no space is available on the last page a new page is created and the row is inserted on the new page. New rows are then appended until some predefined amount of space is filled before a search is done again. As a result, insertion of a row into the database management system does not incur the worst-case cost of searching the entire free space map.

公开(公告)号：CA2306968C

公开(公告)日：2004-11-30

申请号：CA2306968

申请日：2000-04-28

Applicant: IBM CANADA

Inventor： MCARTHUR CATHERINE ,  WINER MICHAEL J ,  LINDSAY BRUCE G

IPC: G06F17/30

Abstract: A callback to a data manager is earned out from an index manager in a query processing system for an index-data fetch to enable an index page held stabilized by an index manager to remain stabilized during predicate checking or data consumption operations. The ind ex manager locates a data identifier in an index and calls back to a data manager to access the data indicated by the data identifier. The data manager may carry out a predicate check or a data consuming operation on the data and if this is the case the index manager may access the next da ta identifier in the index when the data manager callback is complete. The index page need not be destabilized in such a case.

公开(公告)号：CA2425033A1

公开(公告)日：2004-10-08

申请号：CA2425033

申请日：2003-04-08

Applicant: IBM CANADA

Inventor： BHATTACHARJEE BISHWARANJAN ,  PADMANABHAN SRIRAM K ,  WINER MICHAEL J ,  CRANSTON LESLIE A ,  HURAS MATTHEW A ,  MCARTHUR CATHERINE S ,  MALKEMUS TIMOTHY R

IPC: G06F16/20 ,  G06F17/30

Abstract: A multi-level locking hierarchy for a relational database includes a first locking level applied to a multi-dimensionally clustering table, a second locking level applied to blocks within the table, and a third locking level applied to rows within the blocks. The hierarchy leverages the multi-dimensional clustering of the table data for efficiency and to reduce lock overhead. Data is normally locked in order of coarser to finer granularity to limit deadlock. When data of finer granularity is locked, data of coarser granularity containing the finer granularity data is also locked. Block lock durations may be employed to ensure that a block remains locked if any contained row remains locked. Block level lock attributes may facilitate detection of at least one of a concurrent scan and a row deletion within a block. Detection of the emptying of a block during a scan of the block may bar scan completion in that block.

公开(公告)号：CA2370601A1

公开(公告)日：2003-08-05

申请号：CA2370601

申请日：2002-02-05

Applicant: IBM CANADA

Inventor： LEE JESSE ,  ZHENG ROGER LUO QUAN ,  WINER MICHAEL J

IPC: G06F12/00 ,  G06F17/30 ,  G06F17/40

Abstract: A method and apparatus for managing log records during rollback of a group o f changes within a unit of work in a database system. In one embodiment, a method includes determining for each change being rolled back if the change was performed on a temporary database object or a permanent database object; for each change that was performed on a permanent database object, creating an associated compensation log record indicating that the change ha s been rolled back; and for each change that was performed on a temporary database object, assessing if a compensation record is desired based on predetermined criteria, and selectively creating, based on the assessment, an associated compensation log record indicating that the change to the temporary object has been rolled back.

公开(公告)号：CA2279028C

公开(公告)日：2002-09-10

申请号：CA2279028

申请日：1999-07-29

Applicant: IBM CANADA

Inventor： ZHENG ROGER LUO Q ,  WINER MICHAEL J ,  HURAS MATTHEW A ,  MCINNIS DALE M ,  OFER EFFI

IPC: G06F17/00 ,  G06F17/30

Abstract: A database management system having a dropped table recovery flag. If the dropped table recovery flag is on, at the time that a table is dropped an entry will be made in a dropped table history file. The dropped table history file contains a timestamp of the time of table dro p, a unique dropped table identifier, and table definition information. The system includes a command to permit the table space of a dropped table to be restored and rolled forward to the point of t he dropped table drop. The restored and rolled forward dropped table data is written to a flat file. Th e flat file data is loaded into a recreated table in the current table space to recover the dropped table.

公开(公告)号：CA2281287A1

公开(公告)日：2001-03-01

申请号：CA2281287

申请日：1999-09-01

Applicant: IBM CANADA

Inventor： CRANSTON LESLIE A ,  HURAS MATTHEW A ,  HOP HING NELSON ,  LINDSAY BRUCE G ,  WINER MICHAEL J

IPC: G06F17/30

Abstract: A method of searching a table in a database management system for free space for inserting a new record into the table. The table resides in a storage media, and includes a series of pages capable of storing a plurality of records. The table has a clustering index defined in a column of the table. The new record has a new record attribute for storing in the column o f the table when the new record is stored in the table. The method comprises searching for a target page in the series of pages, the target page being selected to maintain clustering when the new record is inserted thereon. Once the target page has been located, it is searched for sufficient free space t o accommodate the new record. If sufficient free space is found on the target page, then the new record is inserted on the target page. If sufficient free space is not found on the target page, then a target neighbourhood of pages in the series of pages is searched for sufficient free space to accommodate the new record. The target neighbourhood of pages surrounds the target page. If sufficient free space is found on a page in a target neighbourhood of pages, then the new record is inserted on to this page in the target neighbourhood of pages. If sufficient free space is not found in the target neighbourhood of pages, then the methodfurther comprises searching for sufficient free space to accommodate the new record outside the target neighbourhood of pages. If sufficient free space is found outside the target neighbourhood of pages, then the new record is inserted on a non-neighbourin g page outside the target neighbourhood of pages. If sufficient free space is not found outside the target neighbourhood of pages, then a new page having the new record is appended to the end of table.