US6334128B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for efficiently refreshing sets of summary tables and materialized views in a database management system
Assignee: Oracle International Corp
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Filing: 1998-12-28
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Granted: 2001-12-25
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Expires: 2018-12-28
Abstract
Abstract A method and apparatus for refreshing stale materialized views is provided. Prior to executing a query to refresh a materialized view from data in the base tables of the materialized view, the query is rewritten to refresh the materialized view from data in one or more other materialized views. To take advantage of the efficiency gained by refreshing a materialized view based on another materialized view, a refresh sequence is established based on the dependencies between materialized views in the database system. The dependencies indicate which materialized views can be refreshed from which other materialized views. When a materialized view can be refreshed based on any one of a number of eligible materialized views, the refresh sequence may additionally take into account the relative benefit associated with refreshing the materialized view with each of the eligible materialized views.
Inventors
- 👤 William D. Norcott
- 👤 Mohamed Ziauddin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 12:03
CPC Classifications
G; G06; G06F; G06F16/00; G06F16/20; G06F16/23; G06F16/2393; Y; Y10; Y10S; Y10S707/00; Y10S707/99931; Y10S707/99933; Y10S707/99935; Y10S707/99938; Y10S707/99941; Y10S707/99943
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
49 words
A method for refreshing a stale materialized view in a database system, the method comprising the steps of: executing a query that retrieves data from a fresh materialized view in said database system; and refreshing said stale materialized view based on the data retrieved from said fresh materialized view.
Claim 2
Independent Claim
49 words
A method for refreshing a stale materialized view in a database system, the method comprising the steps of: executing a query that retrieves data from a fresh materialized view in said database system; and refreshing said stale materialized view based on the data retrieved from said fresh materialized view.
Claim 3
Dependent Claim
55 words
The method of claim 1 further comprising the step of creating the query that retrieves data from the fresh materialized view by automatically rewriting a refresh query for said stale materialized view, wherein said refresh query references a plurality of base tables for said stale materialized view but does not reference said fresh materialized view.
Claim 4
Dependent Claim
32 words
The method of claim 1 further comprising the step of establishing a refresh sequence that dictates that said fresh materialized view is to be refreshed before said stale materialized view is refreshed.
Claim 5
Dependent Claim
52 words
The method of claim 3 further comprising the steps of: determining dependencies between a plurality of materialized views in said database system, said plurality of materialized views including said stale materialized view and said fresh materialized view; and determining said refresh sequence based on said dependencies between said plurality of materialized views.
Claim 6
Dependent Claim
45 words
The method of claim 3 wherein the step of establishing a refresh sequence includes scheduling the stale materialized view to be refreshed after any one of a plurality of other materialized views are refreshed, said plurality of other materialized views including said fresh materialized view.
Claim 7
Dependent Claim
41 words
The method of claim 4 wherein: the method includes the step of building a dependency graph based on said dependencies between said plurality of materialized views; and the step of determining said refresh sequence is performed based on said dependency graph.
Claim 8
Dependent Claim
119 words
The method of claim 4 wherein: the step of determining said refresh sequence based on said dependencies includes establishing parents for a subset of said plurality of materialized views; generating a plurality of refresh jobs to refresh said plurality of materialized views; initially setting to an active state the refresh jobs associated with materialized views that do not have predecessors; initially setting to a suspended state the refresh jobs associated with materialized views that have parents; executing refresh jobs that are in the active state; and upon completing execution of a refresh job for a particular materialized view, setting to the active state all refresh jobs associated with materialized views for which the particular materialized view is a parent.
Claim 9
Dependent Claim
27 words
The method of claim 7 wherein the step of executing refresh jobs that are in the active state includes executing at least two refresh jobs in parallel.
Claim 10
Dependent Claim
24 words
The method of claim 4 wherein the step of establishing a refresh sequence includes establishing said refresh sequence based on a greedy scheduling approach.
Claim 11
Dependent Claim
25 words
The method of claim 4 wherein the step of establishing a refresh sequence includes establishing said refresh sequence based on an optimal predecessor scheduling approach.
Claim 12
Dependent Claim
25 words
The method of claim 4 wherein the step of establishing a refresh sequence includes establishing said refresh sequence based on a critical path scheduling approach.
Claim 13
Dependent Claim
56 words
A computer-readable medium for refreshing a stale materialized view in a database system, the computer-readable medium bearing instructions for performing the steps of: executing a query that retrieves data from a fresh materialized view in said database system; and refreshing said stale materialized view based on the data retrieved from said fresh materialized view is refreshed.
Claim 14
Dependent Claim
56 words
A computer-readable medium for refreshing a stale materialized view in a database system, the computer-readable medium bearing instructions for performing the steps of: executing a query that retrieves data from a fresh materialized view in said database system; and refreshing said stale materialized view based on the data retrieved from said fresh materialized view is refreshed.
Claim 15
Dependent Claim
59 words
The computer-readable medium of claim 12 further comprising instructions for performing the step of creating the query that retrieves data from the fresh materialized view by automatically rewriting a refresh query for said stale materialized view, wherein said refresh query references a plurality of base tables for said stale materialized view but does not reference said fresh materialized view.
Claim 16
Dependent Claim
34 words
The computer-readable medium of claim 12 further comprising instructions for performing the step of establishing a refresh sequence that dictates that said fresh materialized view is to be refreshed before said stale materialized view.
Claim 17
Dependent Claim
56 words
The computer-readable medium of claim 14 further comprising instructions for performing the steps of: determining dependencies between a plurality of materialized views in said database system, said plurality of materialized views including said stale materialized view and said fresh materialized view; and determining said refresh sequence based on said dependencies between said plurality of materialized views.
Claim 18
Dependent Claim
46 words
The computer-readable medium of claim 14 wherein the step of establishing a refresh sequence includes scheduling the stale materialized view to be refreshed after any one of a plurality of other materialized views are refreshed, said plurality of other materialized views including said fresh materialized view.
Claim 19
Dependent Claim
46 words
The computer-readable medium of claim 15 wherein: the computer-readable medium includes instructions for performing the step of building a dependency graph based on said dependencies between said plurality of materialized views; and the step of determining said refresh sequence is performed based on said dependency graph.
Claim 20
Dependent Claim
131 words
The computer-readable medium of claim 15 wherein: the step of determining said refresh sequence based on said dependencies includes establishing parents for a subset of said plurality of materialized views; the computer-readable medium further includes instructions for performing the steps of generating a plurality of refresh jobs to refresh said plurality of materialized views; initially setting to an active state the refresh jobs associated with materialized views that do not have parents; initially setting to a suspended state the refresh jobs associated with materialized views that have predecessors; executing refresh jobs that are in the active state; and upon completing execution of a refresh job for a particular materialized view, setting to the active state all refresh jobs associated with materialized views for which the particular materialized view was a predecessor.
Claim 21
Dependent Claim
28 words
The computer-readable medium of claim 18 wherein the step of executing refresh jobs that are in the active state includes executing at least two refresh jobs in parallel.
Claim 22
Dependent Claim
25 words
The computer-readable medium of claim 15 wherein the step of establishing a refresh sequence includes establishing said refresh sequence based on a greedy scheduling approach.
Claim 23
Dependent Claim
26 words
The computer-readable medium of claim 15 wherein the step of establishing a refresh sequence includes establishing said refresh sequence based on an optimal predecessor scheduling approach.
Claim 24
Dependent Claim
26 words
The computer-readable medium of claim 15 wherein the step of establishing a refresh sequence includes establishing said refresh sequence based on a critical path scheduling approach.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-12-24 | 2005-06-25 | 2005-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-12-24 | 2009-06-25 | 2009-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-12-24 | 2013-06-25 | 2013-12-25 | $7700.00 | Window Closed / Lapsed |