Interested to Buy Any Domain ? << Click Here >> for more details...
What is the default join strategy in Teradata???
- 5 Answers
- 25603 Views
- IBM, I also Faced
- E-Mail Answers
Answers were Sorted based on User's Feedback
Answer / dg
The Teradata Cost based optimizer will decide the join
strategy based on the optimum path. The common startegies
followed are from Merge, Hash & Nested Join
| Is This Answer Correct ? | 25 Yes | 3 No |
Answer / yuvaevergreen
Three strategies followed by optimizer are:
1.Duplication of rows of one table to every amp
--> This one is opted by optimizer when the non-PI column
is on a small table.
2.Redistribution of the non PI rows of the table to the amp
containing the matching PI row amp.
--> This one is opted when the tables are large. The non PI
column is in one table is redistributed to the amp
containing the matching PI.
3.Redistribute both the rows of the table by hash values.
--> This is chosen when the join is on a column that is not
the PI in either table. This will require the most spool
space.
| Is This Answer Correct ? | 13 Yes | 3 No |
Answer / tdguy
i think there is no "default" join strategy. Optimizer
decides the type of strategy based on the best retrieval
path and other parameters to execute the query. Merge join
strategy, nested join strategy, hash join strategy and
product join strategies are the common strategies followed
by TD.
| Is This Answer Correct ? | 7 Yes | 1 No |
how to delete duplicate records in multi set table without using any tables
2 Answers Accenture, Nest, South Nests Software Solution, Spiro Solutions,
Explain some differences between mpp and smp?
How can we pass Variable in Bteq with out using shell script Is it possible or not If possible let me know how can we pass varaibale
What is meant by a Virtual Disk?
What is the use of having index on table?
what are the day to day activities of teradata DBA ?
IBM QUESTION As all we know PE takes the SQL Request and it will give responce for that query. what is the internal process happening.how it is taking that sql from the system????? thanks in Advance
2 Answers Cap Gemini, IBM, Infosys,
What is the particular designated level at which a LOCK is liable to be applied in Teradata?
If a Node is busy what are the steps you can take to avoid ?
What are the steps involved in the process flow of the sql statement through channel attached system?
How to find No. of Records present in Each AMP or a Node for a given Table through SQL?
Why FLOAD does not support multiset tables??
Teradata 
