When should a primary key be declared non-clustered?
Nov 11, 2011 · Having a clustered index key with this low selectivity key as the leftmost key, e.g. , often makes sense because of ranges scans that look for all entries in a particular 'state'. One last note …
performance - Guid vs INT - Which is better as a primary key ...
Use: a Key Mapping Table The TableA.ID is used locally in your database as the Primary Key, and the key to use for JOINing. TableAMap.ID is the same as TableA.ID, and TableAMap.UniversalID is …
Should every table have a single-field surrogate/artificial primary key?
Sep 24, 2011 · However, it sometimes seems to be a matter of policy to have an auto-incrementing integer field as the primary key of each table. Is this always the best idea to have such a single-field …
Primary Key Int vs String - Database Administrators Stack Exchange
Sep 9, 2019 · While it is possible to cascade primary key changes to child tables it is a pain. On balance, for your case, I'd go with the int-keyed design. If the names were set by some external authority and …
MySQL: Should I add NOT NULL UNIQUE to the field for primary key?
Apr 21, 2021 · The PRIMARY KEY column (s) will become NOT NULL. More correct "columns mentioned in PK expression" - PK may be built by any valid expression and not refer to column …
Should a composite primary key out of 3-4 attributes or a unique ...
Dec 3, 2018 · Should a composite primary key out of 3-4 attributes or a unique artificial ID should be used for the situation below? Ask Question Asked 7 years, 1 month ago Modified 7 years, 1 month ago
What is the difference between a primary key and a superkey in a DBMS
Jul 20, 2014 · A Primary Key is a minimal Candidate Key, which is to say all constituent columns are strictly required in order to ensure uniqueness. As a database developer/designer of 30 years …
Retrieving all PK and FK - Database Administrators Stack Exchange
Mar 19, 2013 · I have a big database that I need to extract all primary keys and foreign keys from each table. I have pgAdmin III. Is there a way to do this automatically and not go over each table manually?
database design - When should a primary key be meaningful?
Mar 18, 2018 · A Primary Key uniquely identifies a row. There are possibly other columns in a table with unique values, so they can also uniquely identify a row (Candidate Keys), but the Primary Key is the …
database design - Difference between candidate key & primary key ...
Apr 16, 2017 · What is the differences between candidate key and primary key?