Oracle database Objects

An Oracle database object, also known as a schema object, is a collection of logical structures in which the most basic database object is a table. Common database objects include synonyms, sequences, views, and so on.

1. View

Views can restrict a set of behavior accesses in a table, hide the complexity of the data, simplify the user's SQL, modify the base table definition, and provide data from another perspective by renaming the column.

2. Trigger (Trigger)

If you want to change the view, you can use the trigger.

3. Data dictionary

Oracle is divided into static data dictionaries and dynamic Data dictionaries.

static data dictionary:

dba_***: View all user tables

all_***: See all the tables that the user can see

user_***: Table created by this user

Dynamic Data dictionary:

v$***

View the efficiency of executed SQL

1 SELECT * FROM V$database

View the current database

1 SELECT * FROM V$sqlarea

Querying users who are currently connected to the database

1  Select *  from

4.DBLINK

Used to access the remote database

To create a network service name for a remote database, create a Dblink

In the database links, create, access the statement plus the connection name, for example:

1 Select *  from jx0404@Dbl_link

Dbl_link is the name of the connection that was created.

5. Synonyms (synonyms)

Purpose: Block the name of the object and its holder, simplifying SQL for the user

Oracle database Objects