There are
two general types of databases: flat-file databases, which are much like your /etc/passwd
file, and relational databases, which are much more complex and require much more
structure to organize them. Flat-file databases are poor performers and are not truly scalable.
A flat-file database is the opposite of a relational database, which is hierarchical.
Relational databases, on the other hand, are specialized to handle large amounts of data.
They are scalable, which means that they grow well, unlike their flat-file counterparts.
Relational databases are organized by fields, records, and tables. In a relational database, a
field is a single piece of information. A record is one complete set of fields, and a table is a
collection of records. This is essentially what makes up the logical structure of databases.
In a database, each table is identified by a name, such as Contacts. Each table contains
records, also called rows, that contain the actual database data. For example, suppose we
were to define a table called Contacts and create the following three records:
Last First Address City State
Coughanour David 578 E.
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