What is Join Index in TD and How it works?
Answer Posted / veni botcha
JOIN INDEX:
-----------
Join Index is nothing but pre-joining 2 or more tables or
views which are commonly joined in order to reduce the
joining overhead.
So teradata uses the join index instead of resolving the
joins in the participating base tables.
They increase the efficiency and performance of join queries.
They can have different primary indexes than the base tables
and also are automatically updated as and when the base rows
are updated. they can have repeating values.
There are 3 types of join indexes:
1)Single table join index - here the rows are distributed
based on the foreign key hash value of the base table.
2) Multi table join index - joining two tables.
3) Aggregate join index - performing the aggregates but only
sum and count.
| Is This Answer Correct ? | 43 Yes | 9 No |
Post New Answer View All Answers
What do you mean by tpt in teradata?
How do you verify a complicated sql?
What is the command in bteq to check for session settings ?
What is the primary index in teradata?
Why managing the data is important?
Can we have an unconnected lkp to lookup a db2 record against a teradata record? Doesnt seem to work. I could be wrong
What are the available join types in teradata?
What are the different methods ot loading a dimension table? A fact table etc?
What is a clique?
What are the steps involved after the disk manager passes the request?
Explain how spool space is used.
While creating table my dba has fallback or no fallback in his ddl. What is that?
How can we check the version of Teradata that we are using currently?
How do you see a ddl for an existing table?
Explain the term 'columns' related to relational database management system?