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The Ultimate Index-Less Foreign-Key Finder

By Jesse Roberge, 2009/10/15

Total article views: 572 | Views in the last 30 days: 145

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Util_FKsWithoutIndexes
By Jesse Roberge - YeshuaAgapao@Yahoo.com

Searches for foreign key constraints that don't have fully matching indexes.
The best partial matching indexes are outputted with MatchCounts and column comparisons
Generates a CREATE INDEX template for each foreign-key with no matching index or a partial-matching index.
Customize as needed (add includes, if you want it clustered, or if it should be a part of the primary key, or if you want to merge with another index)
FKs missing full matching indexes can severely hurt the performance of DELETES on the referenced table due to table-scans for checking referential integrity,
as well as SELECTS on the referencing tables where the foreign-key column(s) are in the WHERE or JOIN predicates (This will affect you whether a constraint exists or not).
This only checks the first N columns of the index where N is the number of columns in the foreign key constraint.
Index column order is not verified beyond this (A two-col FK that has 1 matching column in the 2nd col of a 3-col index will be outputted as a partial match)
If your database has no foreign key constraints, then this tool will be worthless to you.
Many databases have partial foreign key constraint coverage. This only works on related tables where constraints are declared.

Required Input Parameters:
None

Optional Input Parameters:
@Delimiter VarChar(1)=','

Usage:
EXECUTE Util.Util_FKsWithoutIndexes

Copyright:
Licensed under the L-GPL - a weak copyleft license - you are permitted to use this as a component of a proprietary database and call this from proprietary software.
Copyleft lets you do anything you want except plagiarize, conceal the source, or prohibit copying & re-distribution of this script/proc.

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation, either version 3 of the
License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.

see <http://www.fsf.org/licensing/licenses/lgpl.html> for the license text.

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By Jesse Roberge, 2009/10/15

Total article views: 572 | Views in the last 30 days: 145
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Related tags

Administration     Search    
foreign key constraints     SQL Server 2005    
foreign keys     tables    
Index Management     TSQL    
Indexes     T-SQL    
Maintenance and Management     T-SQL Aids    
Performance     Utility    
Performance Tuning    
 
 
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