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What is the difference between a schema and a table and a database?

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Is a schema the same as a database?

SCHEMA vs DATABASE The schema is the structural definition of the database while database is the collection of organized and interrelated data. database has the schema and records for the tables, but schema includes tables, attribute name, attribute type, constraints, etc.

Is schema same as table in SQL?

Table basics. SQL Server tables are contained within database object containers that are called Schemas. The schema also works as a security boundary, where you can limit database user permissions to be on a specific schema level only. You can imagine the schema as a folder that contains a list of files.

What is the difference between the database schema and the database instance?

Schema refers to the overall description of any given database. Instance basically refers to a collection of data and information that the database stores at any particular moment. The schema remains the same for the entire database as a whole.


schema -> floor plan

database -> house

table -> room


A relation schema is the logical definition of a table - it defines what the name of the table is, and what the name and type of each column is. It's like a plan or a blueprint. A database schema is the collection of relation schemas for a whole database.

A table is a structure with a bunch of rows (aka "tuples"), each of which has the attributes defined by the schema. Tables might also have indexes on them to aid in looking up values on certain columns.

A database is, formally, any collection of data. In this context, the database would be a collection of tables. A DBMS (Database Management System) is the software (like MySQL, SQL Server, Oracle, etc) that manages and runs a database.


In a nutshell, a schema is the definition for the entire database, so it includes tables, views, stored procedures, indexes, primary and foreign keys, etc.


This particular posting has been shown to relate to Oracle only and the definition of Schema changes when in the context of another DB.

Probably the kinda thing to just google up but FYI terms do seem to vary in their definitions which is the most annoying thing :)

In Oracle a database is a database. In your head think of this as the data files and the redo logs and the actual physical presence on the disk of the database itself (i.e. not the instance)

A Schema is effectively a user. More specifically it's a set of tables/procs/indexes etc owned by a user. Another user has a different schema (tables he/she owns) however user can also see any schemas they have select priviliedges on. So a database can consist of hundreds of schemas, and each schema hundreds of tables. You can have tables with the same name in different schemas, which are in the same database.

A Table is a table, a set of rows and columns containing data and is contained in schemas.

Definitions may be different in SQL Server for instance. I'm not aware of this.