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what is the difference between the join and look up
explin me one exmple
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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 |
Hi friends, I am new to datastage, i have one query in datastage any one you please give reply to my post. I have a workbook (excel sheet) named as eg: xxxx, in that i have two tables emp(eid, ename, salary, deptno) and dep(deptno, name, state). in my source i have ODBC enterprise stage read the emp table and dept table join the two table and write the dept no 10(eid,ename,salary,name,state) values in target(). Thanks, Badari
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