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A candidate key is the estimated substantial value that the join operator assigns. The candidate key is a set index used for each row in the result set. A candidate key is a small set of characters.A super key is the composite key of two or more index attributes, which form a representative and unique value to determine from the fact of one row.The candidate key is the primary key you specify in your CREATE TABLE statement. A superkey is a column or set of columns not included in the created table’s candidate key.
What is Super key?
Super keys were the first feature of a database to be added to DBMS. They perform complicated set operations, such as insert, merge and update. Super keys can also be used as indexes on specific columns of a table.A super key is a candidate key comprised of more than one attribute, each equal to the data type allowed by the database server (INTEGER or CHARACTER). A super key is the most basic and most minor set of attributes that uniquely identifies rows in a relation. A relation can have at most one super key.
What is the Candidate key?
A candidate key is a list of values for joining the two tables. The deal could be the primary key in a table, it may be related to the value field in another table, or it can be product-specific information about products. A candidate key is crucial that can be used in an SQL query to join data tables.A candidate key is the most miniature set of columns within a table that uniquely identifies each row in the table. Candidate keys may be composed of a single column or multiple columns.
Difference between candidate key and super key?
| Candidate Key | Super Key |
| A candidate key is one attribute used to identify each table record uniquely. | A super key is a subset of the candidate keys present in a table. |
| The Candidate key is a key which has only one non-null value in every candidate key list. | The Super Key is a composite, a combination of more than one attribute. |
| A candidate key is a single identifier uniquely identifying each row in a database table. | A super key consists of multiple columns, where all of those columns should be selected to join two tables. |
| A candidate key is a standard key and can be part of a composite primary key. | A super key is always an attribute (or combination of features) that is not subordinate to a foreign key in another table. |
| The candidate key is the primary key you specify in your CREATE TABLE statement. | A super key is a column or set of columns not included in the created table’s candidate key. |
| A candidate key is a set or combination of attributes uniquely identifying each row in a table. | A super key is a more extensive set that includes a candidate key’s characteristics. |
| The super key is the candidate key with the addition of synonyms for duplicates. | The super key has no duplicate values that are not also present in other columns in the same table. It’s also known as an “exception-free super key”. A super key is a subset of a candidate key. |
| A candidate key is a set of columns in a table that uniquely identify a particular record. | A super key is the intersection or combination of two or more candidate keys, which are themselves different. |
| A candidate key is a single attribute in a table that can uniquely identify each row. | A super key is a collection of columns. Either in a single table or multiple related tables, they can uniquely identify each row in the combined set of tables. |
| The candidate key is the one that consists of all primary keys and their dependents in a table containing more than one column. | The super key is the one that has primary keys only in a single-column table. |
| A candidate key is a candidate for theprimary key of a table. | A super key is a super key of one or more relationships in a relational database. Who can draw a super key from only one relation of the set of links to which it belongs, and it cannot contain any null values? |
