UPDATE and DELETE Restrict - A referential integrity rule that disallows the update or deletion of referenced data.DELETE Cascade - When a referenced row is deleted all associated dependent rows are deleted.
Latest Answer: Foreign key value must exist as PK value on some other  table...FK value can be null but PK can't ...
If a foreign key reference a parent key of the same table is called self-referential integrity constraint.
Latest Answer: Self referential integrity constraint refers to two columns related by referential integrity which belong to the same table.For example ManagerId column in employees table is a foreign key which refers to EmployeeId in the same table. ...
The condition must be a Boolean expression evaluated using the values in the row being inserted or updated and can't contain sub queries, sequence, the SYSDATE,UID,USER or USERENV SQL functions, or
Latest Answer: A check constraint allows you to specify a condition on each row in a table. Note: A check constraint can NOT be defined on a VIEW. The check constraint defined on a table must refer to only columns in that table. It can not refer to columns in other ...
No Limit.
Latest Answer: You can create any number of check constraintsseparated by AND, OR, or NOT to create more complex conditions. ...
Tablespaces and the Database's Schema Objects.
Latest Answer: Oracle Database has Physical and Logical Structure. In Logical Structure contains System tablespace and no of tablespace in database. these tablespace contains datafiles from physical database datafiles ...
A database is divided into Logical Storage Unit called tablespaces. A tablespace is used to grouped related logical structures together.
Latest Answer: It is a Logical area of storage in a Database, that directly corresponds to one or more physical files. ...
Every ORACLE database contains a tablespace named SYSTEM, which is automatically created when the database is created. The SYSTEM tablespace always contains the data dictionary tables for the entire database.
Latest Answer: Every Oracle Database contains a tablespace called system tablespace.This tablespace gets created at the time of database creation and it holds data dictionary information for the entire database. ...
Each databases logically divided into one or more tablespaces one or more data files are explicitly created for each tablespace.
Latest Answer: Databases, tablespaces, and datafiles are closely related, but they have important differences:1) An Oracle database consists of at least two logical storage units called tablespaces, which collectively store all of the database's data. You must have ...
A schema is collection of database objects of a User.
Latest Answer: Schema is a Collection of Database objects of a user.Example: Tables, Views, Synonyms, Sequences, Clusters, Triggers, Procedures, Packages. ...
Schema objects are the logical structures that directly refer to the database's data. Schema objects include tables, views, sequences, synonyms, indexes, clusters, database triggers, procedures, functions
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