EP0422877A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
A method for invalidating access plans in a database system
Assignee: International Business Machines Corp
•
Filing: 1990-10-08
•
Granted: —
•
Expires: 2010-10-08
Abstract
Abstract For each access plan 14, 16 in a database system 10 , dependencies are determined for each database object 20, 22 on which that access plan is dependent. Each dependency has a type. When a relationship changes between database objects, the dependency types of each access plan for those objects is determined. If an access plan has dependencies on the affected database objects which fall within a preselected subset of dependency types, that access plan is invalidated (and subsequently recompiled). If the access plan dependencies are not within the preselected subset of dependency types, the plan remains valid and need not be recompiled.
Inventors
- 👤 Gary Randall Horn
- 👤 Timothy Ray Malkemus
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 20:37
CPC Classifications
G; G06; G06F; G06F17/00; G06F16/00; G06F16/20; G06F16/23; G06F16/2365
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
92 words
A method for identifying access plans ( 14 ) as invalid in a database system ( 10 ), characterised by comprising the steps of: if a relationship between a dependent and parent object changes by dropping ( 80 ) or adding ( 60 ) a foreign key in the dependent object for which the parent object has a primary key, determining for each access plan whether any procedural code within the access plan must be changed; and identifying as invalid all access plans for which any such procedural code must be changed.
Claim 2
Independent Claim
92 words
A method for identifying access plans ( 14 ) as invalid in a database system ( 10 ), characterised by comprising the steps of: if a relationship between a dependent and parent object changes by dropping ( 80 ) or adding ( 60 ) a foreign key in the dependent object for which the parent object has a primary key, determining for each access plan whether any procedural code within the access plan must be changed; and identifying as invalid all access plans for which any such procedural code must be changed.
Claim 3
Dependent Claim
64 words
The method of Claim 1, wherein said determining step comprises the steps of: determining types of access plan dependencies ( 62, 68 ) on the dependent and parent objects; and selecting access plans having dependencies on the parent and dependent objects which are within a preselected subset of all possible dependency types, wherein the procedural code within such selected access plans must be changed.
Claim 4
Dependent Claim
19 words
The method of Claim 2, wherein the possible dependency types comprises select, delete, insert, update, cascade, and key dependencies.
Claim 5
Dependent Claim
90 words
The method of Claim 3, wherein the preselected subset comprises: when the foreign key is added ( 60 ), insert and update dependencies on the dependent object, and delete, update, and cascade dependencies on the parent objects; and when the foreign key is dropped ( 80 ), insert dependency on the dependent table, delete and cascade dependencies on the parent table, combined update dependency on the parent table and key dependency on the dependent table, and combined update dependency on the dependent table and key dependency on the parent table.
Claim 6
Independent Claim
51 words
A method for maintaining referential integrity in a database comprising the steps of: identifying the access plan as invalid, according to the method of any preceding claim; and further comprising the step of: recompiling an access plan when it is next accessed if such a plan has been identified as invalid.
Claim 7
Dependent Claim
89 words
A data processing system including a relational database, said database including means for identifying access plans therein as invalid, said means comprising: means for determining for each access plan whether any procedural code within the access plan must be changed if a relationship between a dependent and a parent object changes by dropping or adding a foreign key in the dependent object for which the parent object has a primary key; and means for identifying as invalid all access plans for which any such procedural code must be changed.
Claim 8
Dependent Claim
89 words
A data processing system including a relational database, said database including means for identifying access plans therein as invalid, said means comprising: means for determining for each access plan whether any procedural code within the access plan must be changed if a relationship between a dependent and a parent object changes by dropping or adding a foreign key in the dependent object for which the parent object has a primary key; and means for identifying as invalid all access plans for which any such procedural code must be changed.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.