Index Scan retrieves all the rows from the table. Index Seek retrieves selective rows from the table.
SQL SERVER – Difference between DISTINCT and GROUP BY – Distinct vs Group By
This question is asked many times to me. What is difference between DISTINCT and GROUP BY? A DISTINCT and GROUP BY usually generate the same query plan, so performance should be the same across both query constructs. GROUP BY should be used to apply aggregate operators to each group. If…
Read MoreSQL SERVER – Fix : Error 8101 An explicit value for the identity column in table can only be specified when a column list is used and IDENTITY_INSERT is ON
This error occurs when the user has attempted to insert a row containing a specific identity value into a table that contains an identity column. Run following commands according to your SQL Statement. Let us learn about the IDENTITY_INSERT.
SQL SERVER – Fix : Error 701 There is insufficient system memory to run this query
Generic Solution: Check the settings for both min server memory (MB) and max server memory (MB). If max server memory (MB) is a value close to the value of min server memory (MB), then increase the max server memory (MB) value. Check the size of the virtual memory paging file.…
Read MoreSQL SERVER – @@IDENTITY vs SCOPE_IDENTITY() vs IDENT_CURRENT – Retrieve Last Inserted Identity of Record
SELECT @@IDENTITY It returns the last IDENTITY value produced on a connection, regardless of the table that produced the value, and regardless of the scope of the statement that produced the value. @@IDENTITY will return the last identity value entered into a table in your current session. While @@IDENTITY is…
Read MoreSQL SERVER – Stored Procedure – Clean Cache and Clean Buffer
DBCC FREEPROCCACHE will invalidate all stored procedure plans that the optimizer has cached in memory. Let us learn how to clean cache.Â
SQL SERVER – Fix: Error Msg 128 The name is not permitted in this context. Only constants, expressions, or variables allowed here. Column names are not permitted.
Error Message: Server: Msg 128, Level 15, State 1, Line 3 The name is not permitted in this context. Only constants, expressions, or variables allowed here. Column names are not permitted. Causes: This error occurs when using a column as the DEFAULT value of another column when a table is…
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