Hai,
I got a sequential file with 73 columns.I want to get the key fields so that i can use those for lookup in my job.So what is the best way to find the keys.I looked for notnull fields,but still i have 50 columns and some of them are also having the repetitive values.Can anyone suggest how to find the Keys(Combination of Fields) which will give the unique value.
Thanks,
Akansha
REGARDING THE kEY VALUES....................
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akansha123
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ray.wurlod
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Sequential files have neither keys nor data types. You can identify columns based upon the metadata, but that's all.
Use a profiling tool to determine whether there are any candidate key columns. A candidate key column contains no nulls and no duplicate values.
Profiling tools such as ProfileStage, AuditStage or QualityStage (Investigate) can report the cardinality of combinations of columns, in case you have no single column candidate keys.
You *could* do it by hand, with SELECT column, COUNT(*) FROM filename GROUP BY column HAVING COUNT(*) > 1; queries executed through an ODBC text driver, but that's a hugely cumbersome approach.
Use a profiling tool to determine whether there are any candidate key columns. A candidate key column contains no nulls and no duplicate values.
Profiling tools such as ProfileStage, AuditStage or QualityStage (Investigate) can report the cardinality of combinations of columns, in case you have no single column candidate keys.
You *could* do it by hand, with SELECT column, COUNT(*) FROM filename GROUP BY column HAVING COUNT(*) > 1; queries executed through an ODBC text driver, but that's a hugely cumbersome approach.
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Any contribution to this forum is my own opinion and does not necessarily reflect any position that IBM may hold.
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Krazykoolrohit
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you will have to get and understand the business logic behind the table to understand what the keys are.
I dont think you can judge a key by looking at the data file. The best you can do is to get a idea of probable columns that can form a key.
A key column can be null. so eliminating it will not work either.
Ask your business user or your datawarehouse architect to provide you with the lookup keys.
I dont think you can judge a key by looking at the data file. The best you can do is to get a idea of probable columns that can form a key.
A key column can be null. so eliminating it will not work either.
Ask your business user or your datawarehouse architect to provide you with the lookup keys.