Do you know what technology keys are? Technological keys are the fields in the relational database that can identify associations can comparisons. You might be surprised to know that all the technology works on specific keys that perform actions or inhibit them. Therefore, this allows applications to filter data so that devices work perfectly.
Technology Keys Types
They are exceptionally important in table maintenance. Here are some major types of technological keys.
- Candidate Key
A candidate key is a unique field that identifies a record.
- Primary Key
A primary key identifies each record separately in a table and should never be the same for two forms. A primary key is a set of one or more fields (columns) in a table that uniquely identifies a record in a database table.
- Alternate Key
Alternate keys belong to the candidate not selected as the primary key. Moreover, the alternate key can also act as the primary key. The alternate key is the “secondary key”.
- Unique Key
A unique key is a set of attributes that can identify a record in a table uniquely.
- Composite Key
It is a set of multiple attributes that can identify each record individually. Consequently, it is also called the “compound” key. A composite key can be a candidate or a primary key.
- Super Key
Super has a set of one or more keys that can identify a record in a table uniquely. A super key for an object is a set of one or more attributes whose expected value identifies the individual in the entity set.
A super key is a combination of a primary key, alternate key, and unique key. It is a subset of a super key. A super key is just a minimum candidate’s key, which means there is no need to be strict with extra columns to ensure the rows’ uniqueness. A super key can contain a column.
- Minimal Super Key
A minimal super key is a set of minimal columns that can identify rows separately. In other words, the minimum numbers of columns that can be combined to give each row of the table a unique value.
- Natural Keys
A natural key is a key consisting of columns that logically relate to other columns inside the table.
- Surrogate Key
A surrogate key is an artificial key used to identify a record in a table. Surrogate keys act as a primary key.
- Foreign Keys
The foreign key creates relationships between tables. Therefore, a foreign key is a field in the database table that is the primary key in another table. A foreign key can accept canceled and duplicate values.
Understanding the technical keys is very important for the comprehension of various processes underlying tabular management. Various technologies and systems are based on these tables for the management of data.