Index
Some specific steps are perform by the oracle engine each time whenever user access record from the data base table. It will first search for a specific table on the hard diskRead More…
Some specific steps are perform by the oracle engine each time whenever user access record from the data base table. It will first search for a specific table on the hard diskRead More…
A view is a logical entity which is created from the base table. The main purpose of creating a view is to provide security over the database table. In some cases whenRead More…
A dual table is oracle’s in built table. It can be used for arithmetic calculations. We can retrieve data from the dual table but cannot insert the data. It has only singleRead More…
Insert statement is used to insert record into the table but we have to specify each value for the column list. There are cases in which some value gets repeated for majorityRead More…
We can use describe command to view logical structure of the table. It displays table structure including column name, data type, size & not null constant. It does not provide information aboutRead More…
In our post “I/O Constraint” and “Business Constraints” we had seen how we can add constraints at the time of table creation using Create table command. If you have not read ourRead More…
Business constraint defines business rules or business policy. Each organization have their specific rules about the data store. Check constraint can be used to define business rules. Check Constraint When constraint cannotRead More…
I/O Constraints Constrains that control data insertion and data retrieval speed are known as I/O (Input-Output) constraints. It includes the following constraints. Primary Key Foreign Key Unique Key Not Null Primary KeyRead More…
Sometimes we need to provide some restriction on the data for security and data integrity reason. We must ensure that only valid and complete data should be stored into the database. OracleRead More…
ALTER TABLE command is used to modify table structure. We can add new column, remove existing column or change data type and size by using alter table command. If records are availableRead More…