When we give SELECT * FROM EMP; How does oracle respond?
- 24 Answers
- 53639 Views
- Accenture, HCL, Infosys, I also Faced
- E-Mail Answers
Answer Posted / umashankar
1.The PARSER scans/reads the SELECT statement and splits it
into some logical units such.
i.e: keywords/reserved word, operators, expressions and
identifiers.
2. SEQUENCE TREE or QUERY TREE is built the logical steps
needed to transform the source data into the format as
needed by the end result.
3. The QUERY OPRIMIZER analyzes the query in various ways
and selects the series of steps that returns the end
results fastest way. The query tree is updated to record
this exact series of steps. The final, optimized version of
the query tree is called the execution plan.
4. The RELATIONAL ENGINE starts executing the execution
plan which was prepared by the Query Optimizer.
5.The RELATIONAL ENGINE requests the STORAGE ENGINE pass up
data from the rowsets requested.
6. The RELATIONAL ENGINE processes the data (returns all
column values from EMP table) returned from the storage
engine to the client.
| Is This Answer Correct ? | 2 Yes | 2 No |
Post New Answer View All Answers
What is the purpose of my sql?
What is sp_helptext?
What is break?
Explain 3 basic parts of a trigger.
What is %s in sql?
what are the differences between char and nchar? : Sql dba
how to rename an existing table in mysql? : Sql dba
What is oracle pl sql developer?
What are the different types of constraints?
What is set serveroutput on?
What is the difference between sql and mysql?
What is the sql query to display the current date?
What is data manipulation language?
What are three advantages to using sql?
What are properties of the transaction?
