what is the difference between the join and look up
explin me one exmple
Answers were Sorted based on User's Feedback
Answer / ankit gosain
Difference Between Join & Lookup:
1. In join stage you can do Inner Join, Left outer, Right
Outer and Full outer join, while in Lookup stage you can do
Inner join & Left outer join only.
2. In join stage you can't have a reject link, while in
lookup stage you can have a reject link for Unmatched
Primary records.
3. In join stage sorted data is mandatory, while in lookup
stage sorted data is not mandatory for lookup source.
4. Join stage requires Hash Partitioned data, while lookup
stage requires Entire partitioned lookup data.
5. In case of Join, Disk I/O is more while it's very less
in case of lookup (since at the time of matching, complete
lookup data is present in the memory).
6. In case of Join Stage, the key column name must be the
same in both the sources, while in case of lookup stage
it's not mandatory.
Cheers,
Ankit :)
| Is This Answer Correct ? | 4 Yes | 0 No |
join lookup
i/p names- left,right,intermediate primary,secondary
join ops - left,right,inner,fullout left,inner
in & out - n i/p(s)-left,right,inner n i/p(s) normal
2 i/p(s)-full outer 2 i/p(s) sparse
1 o/p 1 o/p
rejects - n/a one
sort data- Mandatory optional
KcolNames- Mandatory optional
deduplica- no problem warnings in secondary.
memory - light high
| Is This Answer Correct ? | 0 Yes | 0 No |
1.Join needs key column metadata should be same|Lookup key column metadata its not mandatory to be same
2.Implement Four join in JOIN|But in Lookup only TWO JOIN(left outer,INNER)
3.JOIN does not have reject link | LOOKUP has one reject link
4.Data should be sorted and default is hash partioning |LOOKUP data need not to be in sort and default partioning is ENTIRE
5.Performance is HIGH in JOIN | Performance is less in JOIN
6.Duplicate will arise in JOIN|can handle Duplicate in LOOKUP
| Is This Answer Correct ? | 0 Yes | 0 No |
what is the difference between INROWNUM AND OUTROWNUM IN DATASTAGE SERVER EDITION?
What all the types of jobs you developed?
How will you load you daily/monthly jobs datas in to Fact and Dimension table using datastage.
What are the various kinds of the hash file?
difference between function and procedure...
Hi am sundar, i have datas like 00023-1010 00086-1010 00184F2-1010 . . . . SCH-AS-1010 200-0196-039 . . . Now i want the result as values before the delimiter should come under the column ITEM_CODE and values after the delimiter should come under the column LOC_CODE.. But some datas like "SCH-AS-1010", for this, "SCHAS" should come under the column ITEM_CODE and 1010 should come under the column LOC_CODE.. Pls help me..
Difference between server jobs & parallel jobs?
What is the Difference Between DataStage 7.5 version and 8.1 Version?
In one project how many shared containers are created?
WHAT ARE PERFORMANACE SETTINGS YOU HAVE IMPLEMENTES IN YOUR PROJECT?
Is possible to create skid in dim,fact tables?
there are indexes on a table as index1 with col1, col2 index2 with col2 index3 with col1,col2,col3. if i run a query with col1='100' which index will be used and why