2_Database_concepts_presentation_l2_v2

Database

Field, record, index

What do you remember from previous lesson?

Database
Types of databases
Relational database

Elements of databases:

Field
Record
Index

Records

Data is stored in records. A record is composed of fields and contains all the data about one particular person, company, or item in a database. In this database, a record contains the data for one customer support incident report. Records appear as rows in the database table. A record for Log ID 1201242 is highlighted in figure below.

Field

A field is part of a record and contains a single piece of data for the subject of the record. In the database table illustrated in figure below, each record contains four fields:
Log ID , Operator, Resolved,Duration.

Index

A database index is a data structure that improves the speed of data retrieval operations on a database table at the cost of additional writes and storage space to maintain the index data structure. Indexes are used to quickly locate data without having to search every row in a database table every time a database table is accessed. Indexes can be created using one or more columns of a database table, providing the basis for both rapid random lookups and efficient access of ordered records.

Index

Personal work

Circle fields, records in table that you made on previous lesson.
Create an Index for your table.

Thanks for the attention!