Database Concepts

What two categories do oracle database objects fall under

What two categories do oracle database objects fall under

Schema and Non-schema objects

What is an Entity

An entity is the smallest unity containing a meaningful set of data. Examples are rows, columns, and tables.

What is a table?

A table is the base unit of database to store data, formatted with columns and rows

What’s a schema

\n Schema is a set of rules specifying the structure and behavior of data in a database. User is the individual who uses the database system to store and process data.

What’s a materialized view

Has a real table filled by a SQL query The real table is truncated and refilled with a specific time frequency.

What does SQL stand for?

Structured Query Language

What does RDBMS stand for?

Relational Database Management System

What does a relation mean?

A connection between two tables.

What is a view

A virtual table that provides access to a subset of columns or some restricted rows from one or more tables. They act like a real table, but do not physically use any space for the returning data.

What are triggers?

Complied PL/SQL program units stored in the database and executed with a specific event like an insert, update, delete, or create, etc. They are used for performing other operations "BEFORE", "ON" or "AFTER" the main operation.

What are synonyms?

Is an alternative name or an alias for the database objects. By using these you can query other user's objects without writing its schema name

What are sequences?

Database objects which generate unique integers and generally used for primary key values (unique values for a row).

What are packages?

The schema objects that are complied and stored in the database and consist of logically grouped SQL and PL/SQL codes, variables, cursors, etc. in it to perform one or more than one operations by using its functions or procedures.

Databases

A place that we store an organized collection of data.

Database Links

Are the connections between two physical database servers.

What are constraints?

Constraints are the rules for restricting invalid data entries into tables.

Hierarchical DBMS

This type of DBMS uses the parent-child relationship for storing the data.