If you are using SSIS to upload data to your target table, you can use a Fuzzy Grouping Transformation before inserting records to the destination table to ignore duplicate records and insert only unique records. Here, in the image below, you can see 9 records are coming from source, but only 3 records are being inserted into the target table, that's because only 3 records are unique out of the 9 records.
Refer to Script 2 above to see more about these 9 records that were used. In the Fuzzy Grouping Transformation editor, on the Columns tab you specify the columns which you want to be included in grouping. As you can see in the below image I have chosen all 3 columns in my consideration for grouping.
In the Fuzzy Grouping Transformation, you might add a conditional split to direct unique rows or duplicate rows to two destinations. Here in the example you can see I am routing all the unique rows to the destination table and ignoring the duplicate records. It inserts rows that don't exist and updates the rows that do exist. With the introduction of the MERGE SQL command, developers can more effectively handle common data warehousing scenarios, like checking whether a row exists and then executing an insert or update or delete.
The MERGE statement basically merges data from a source result set to a target table based on a condition that you specify and if the data from the source already exists in the target or not.
With this you can make sure no duplicate records are being inserted into the target table, but rather updated if there is any change and only new records are inserted which do not already exist in the target. For more information about this you can click here. In teradata. I work in a DW environment where in i get a requirment of deleting duplicate records within a huge set of data, which of the above method would be the fastest?
I believe, the problem in the 'Temporary table' example, there's a problem when Orginal table get rows from Temp Table. Thanks, this is the most useful and clear example In how to fix a problem and how to explain it in the best way possible, your post is elegant and do the job nicely. Thank you very much. Your Script 5 CTE code worked a charm. I could't get several other sites' suggested code to work for my purposes. Please note, the table which I have used in the query does not have ID column which has different value for the same employee as indicated in your query.
In Using temporary table method, you have to capture the distinct records instead of retrieving all the records from the table. ID , E1. FirstName, E1. LastName, E1. And its the same case with the next method: "Creating new table with distinct records and renaming it..
I just checked the script you mentioned, it worked fine. Something is also wrong in your " Creating new table with distinct records and renaming it.. Reena Jain replied to theiry henry on Aug AM. Radhika roy replied to theiry henry on Aug AM. Devil Scorpio replied to theiry henry on Aug PM. All Questions. New Question. Timoteivn Borgvn Storgt Learn more. Asked 4 years, 3 months ago. Active 4 years, 3 months ago. Viewed 11k times. Illustration I get But I want MoonKnight MoonKnight Add a comment.
Active Oldest Votes. MoonKnight I've changed the data type from int to float, to try and make it look more like yours but it was just a guess? What row do you think needs to be different? Rn AND Src. Thanks, but I would like to do this all with one operation. Merging and then deleting might be too expensive for me to deal with.
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