What is Denormalization in Data base Why we should we do this..?
=> This is a attempt to optimize the read performance of a database by adding redundant data or by grouping data.In some cases.
As normalized Form of data is Stored in different tables so retrieval of desired data based on certain condition Takes more logical resource ..
so to reduce the logical load we need to do demoralize the data.
pros retrieval is fast
cons Takes more Disk Space and having data redundancy .
Example with pentaho PDI
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select Row De-normalizer under Transformation Tab of PDI
now Feed Data to this step using table input or XLS Input
Now
1)select key Field from drop down
2)press Get field Button To get group Fields
3)Slect Target Column,
4)Select Value Column,
5) Key Value
Now You can dump the desired Denormalized data in in table or xls..
:)
=> This is a attempt to optimize the read performance of a database by adding redundant data or by grouping data.In some cases.
As normalized Form of data is Stored in different tables so retrieval of desired data based on certain condition Takes more logical resource ..
so to reduce the logical load we need to do demoralize the data.
pros retrieval is fast
cons Takes more Disk Space and having data redundancy .
Example with pentaho PDI
---------------------------------------------------
select Row De-normalizer under Transformation Tab of PDI
now Feed Data to this step using table input or XLS Input
Now
1)select key Field from drop down
2)press Get field Button To get group Fields
3)Slect Target Column,
4)Select Value Column,
5) Key Value
Now You can dump the desired Denormalized data in in table or xls..
:)
I want to chage the alignment of Header and detail of a report which is made through wizard.
ReplyDeleteRight now i am facing a problem in which if i change the alignment of a coloumn heading thorugh wizard if autometically effect on the data also.
please help