DB2 Binds and Access Path Questions
- What is a DB2 bind?
Answer: A DB2 bind is a process that builds an access path to DB2 tables.
- What is a DB2 access path?
Answer: An access path is the method used to access data specified in DB2 sql statements.
- What is a DB2 plan?
Answer: An application plan or package is generated by the bind to define an access path.
- What is normalization and what are the five normal forms?
Answer:
Normalization is a design procedure for representing data in tabular format. The five normal forms are progressive rules to represent the data with minimal redundancy.
- What are foreign keys?
Answer: These are attributes of one table that have matching values in a primary key in another table, allowing for relationships between the tables.
- Describe the elements of the SELECT query syntax.
Answer: SELECT element FROM table WHERE conditional statement.
- Explain the use of the WHERE clause.
Answer: WHERE is used with a relational statement to isolate the object element or row.
- What techniques are used to retrieve data from more than one table in a single SQL statement?
Answer: Joins, unions and nested selects are used to retrieve data from more than one table in a single SQL statement.
- What do the initials DDL and DML stand for and what is their meaning?
Answer: DDL is data definition language and DML is data manipulation language.
a) DDL statements are CREATE, ALTER, TRUNCATE.
b) DML statements are SELECT, INSERT, DELETE and UPDATE.
- What is a view and why do we use it?
Answer:
A view is a virtual table made up of data from base tables and other views, but not stored separately.