发明名称 |
Structured indexes on results of function applications over data |
摘要 |
Indexed views or materialized views are used as a secondary index on a base table with multi-valued attributes. This provides for using the index to search in the nested data. Moreover, indexing is provided on the result of an unnest operation. Indexing a view on the result of an unnesting operation provides the ability to index the contents of a nested collection. One such unnesting operation is "cross apply unnest". This provides additional options for a query execution plan, leading to a more optimized query. A back-join is provided from the indexed view to the base table to allow fields from the base table that are not present in the indexed view to be included in a result of a query on the table which is processed using the indexed view as an access path. This provides a means of including columns in the query result that are not in the indexed view but are in the base table. The back-join is supported from a single-table indexed view to the base table via a unique clustering key which acts as a logical row locator. Thus, the system can back-join to the base table from an indexed view via the unique clustering key. These features allow the use of indexed views to index a table on the contents of multi-set or multi-valued attributes.
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申请公布号 |
US2005198016(A1) |
申请公布日期 |
2005.09.08 |
申请号 |
US20050051447 |
申请日期 |
2005.02.04 |
申请人 |
MICROSOFT CORPORATION |
发明人 |
CUNNINGHAM CONOR J.;HANSON ERIC N.;JOSHI MILIND M.;GALINDO-LEGARIA CESAR A.;WAAS FLORIAN M. |
分类号 |
G06F7/00;G06F12/00;G06F17/30;(IPC1-7):G06F12/00 |
主分类号 |
G06F7/00 |
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