Is the Oracle_SID the same the login name on Oracle?

Question

I come from an SQL Server/Sybase background.

I'm used to referring to tables in a particular schema, in the format:

SCHEMA_NAME..TABLE_NAME. 

I asked a colleague today about creating a fresh 'schema' on an Oracle database. His response was:

On Oracle you get the Schema name of the logged in user. The schema name is the same as the login user name.

That didn't sound quite right to me. I'm guessing this is an oversimplification, or some concepts are mixed up.

My assumption is the that Oracle_SID is the same as my concept of 'schema' from the Sybase world.

My question is: Is the Oracle_SID the same the login name on Oracle?

Answer 1

Your colleague is right. A schema and a user are pretty much the same in Oracle. When you create a user, a schema with the same name is automatically created.

Quote from the manual:

A schema is a collection of logical structures of data, or schema objects. A schema is owned by a database user and has the same name as that user. Each user owns a single schema

There is no concept of a "database" the way there is in Sybase or SQL Server.

The SID is the identifier for an instance which is something completely different.

A fully qualified table name in Oracle only consists of two elements: the schema (=owner) and the object name: schema_name.table_name and they are separated by a single .

My question is: Is the Oracle_SID the same the login name on Oracle?

The answer to that is: NO, absolutely not