Question - Explain briefly about record properties?
Answer -
KEY: The record knows a field, which uniquely identifies each row, as a key.
- We will search and retrieve data from the database according to the key field.
- This will not allow duplicate and null values.
- It is a primary key
- It allows multiple keys
- Maximum keys allowed in a record is 15
- It should be placed at the top of the record definition.
Duplicate Order Key:
1. It provides a way of ordering data in the table when the duplicate values are allowed.
2. It will create index for the column. However the index can be disabled.
Alternate Search key:
1. it identifies the field as a key that provides an alternative path into table data.
2. Due to alternate search key the system becomes slow, because database index will be created when SQL creates the tables, so it will consume the disk space.
3. It allows duplicate values.
4. Alternate search will be seen in the search dialog box when update/display mode is selected.
Descending order key:
It is used to retrieve data in the form of 3-2-1 or C-B-A and normally it is used in Effective date.