I have a table with emp id, emp name, dept id and sal where
dept id is NUSI. SEL * FROM EMP WHERE DEPTID = 100. Can any
one explain how it will fetch the record.
- 4 Answers
- 8789 Views
- I also Faced
- E-Mail Answers
Answer Posted / ajain
Whenever NUSI is created, subtable will be created for each AMP's with the fields rowid and secondary index value.For NUSI ,subtable will be AMP local ie it will be having the records which are specific to the particular AMP.
When someone queries with the NUSI, all the AMPs will search in their own subtable for particular secondary index .For AMPs which found the particular record in their subtable ,it will retrieve the actual data from the AMP and PE will be consolidating the records and give to user
Since NUSI involves all AMP operation , PE will be deciding whether FULL table scan or ALL AMP operation will be more efficient .
| Is This Answer Correct ? | 4 Yes | 0 No |
Post New Answer View All Answers
Difference between star and snowflake schemas?
What are aggregate tables? How do you design them using teradata?
What are the uses of bynets in multi-node systems?
How can you track login parameters of users in teradata?
What are the various indexes in teradata?
What are the frequently used data types in teradata?
What is the command in bteq to check for session settings ?
What are the various etl tools in the market?
If a Node is busy what are the steps you can take to avoid ?
Explain the new features of teradata?
How to identify ppi columns?
Hi, If anyone has TD 14 Basics dumps or study materials, please share. nirmaaal1991@gmail.com
What is the syntax for case when statement?
Explain BYNET.
What are the design features involved in teradata?
