How to Efficiently Retrieve the Last Row in SQL Server?

Retrieve the Last Row in SQL Server: An Optimized Approach

Determining the most efficient method for reading the last row in a table is crucial for optimizing database operations. When your table is indexed on a unique key, the "bottom" key values represent the last row.

In Microsoft SQL Server, there are two effective techniques for accomplishing this task:

1. Using ORDER BY DESC and TOP 1:

   This approach utilizes the ORDER BY clause in conjunction with TOP 1 to retrieve the last row based on the descending order of the indexed column. For example, the query below selects the last row from the table_Name table, ordered by the unique_column in descending order and limiting the results to the first row:

   SELECT TOP 1 *
   FROM table_Name
   ORDER BY unique_column DESC

2. Utilizing the ROW_NUMBER() Function:

   Alternatively, you can use the ROW_NUMBER() function to assign a sequential number to each row in the table. The last row will have the highest row number. You can then use a query like this to retrieve the last row:

   SELECT *
   FROM (
       SELECT *, ROW_NUMBER() OVER (ORDER BY unique_column DESC) AS RowNum
       FROM table_Name
   ) AS SubQuery
   WHERE RowNum = (SELECT MAX(RowNum) FROM SubQuery)

Both methods offer efficient solutions for reading the last row in SQL Server when the table is indexed on a unique key. Selection of the optimal technique depends on specific table characteristics and query performance requirements.

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