公开(公告)号：CA2279092C

公开(公告)日：2002-09-10

申请号：CA2279092

申请日：1999-07-29

Applicant: IBM CANADA

Inventor： CRANSTON LESLIE A ,  MCARTHUR CATHERINE S ,  HURAS MATTHEW A

IPC: G06F17/30

Abstract: A method executed by a data processor for scanning a reverse range. The scan is conducted in an index for a table having an upper end and a lower end. The reverse ran ge has a start key value for defining the reverse range, and the index has a set of keys representing a set of records and record attributes in the table. Each key in the set of keys has a RID designating a record in the table and a key value corresponding to an attribute of the record in the table. The method includes the steps of searching the index for a start key, selecting an upper bound of the reverse range, and, if the upper bound is the first key in the index, indicating that the index does not contain any key value within the reverse range, or, if the upper bound is not the first key in the index, then fetching each key below the upper bound in the index.

公开(公告)号：CA2427071A1

公开(公告)日：2004-10-28

申请号：CA2427071

申请日：2003-04-28

Applicant: IBM CANADA

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

IPC: G06F16/22 ,  G06F17/30

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 plurali ty 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 t he 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 uniq ue 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 whe n pages in the block are empty and for identifying when the entire block is empty so that t he block may be disassociated from its associated dimension values and associated cell.

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：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.

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：CA2279092A1

公开(公告)日：2001-01-29

申请号：CA2279092

申请日：1999-07-29

Applicant: IBM CANADA

Inventor： MCARTHUR CATHERINE S ,  CRANSTON LESLIE A ,  HURAS MATTHEW

IPC: G06F17/30

Abstract: A method executed by a data processor for scanning a reverse range. The scan is conducted in an index for a table having an upper end and a lower end. The reverse ran ge has a start key value for defining the reverse range, and the index has a set of keys representing a set of records and record attributes in the table. Each key in the set of keys has a RID designating a record in the table and a key value corresponding to an attribute of the record in the table. The method includes the steps of searching the index for a start key, selecting an upper bound of the reverse range, and, if the upper bound is the first key in the index, indicating that the index does not contain any key value within the reverse range, or, if the upper bound is not the first key in the index, then fetching each key below the upper bound in the index.