Two of my articles on managing duplicate rows: how to count duplicate records and how to delete duplicate records in SQL Server tables.
EXP and LOG: Read Approximate Inverse Calculations
EXP and LOG can undo each other mathematically, but their SQL float calculations remain approximate. Keep a deliberate display scale and test only the permitted logarithm domain.
Setting Up Database Mail for Alerts
Setting up Database Mail for alerts means creating an account and profile, testing delivery, linking Agent, and checking the queue when mail stops.
Check Constraints That Enforce Business Rules
Check constraints keep row rules inside SQL Server, but NULL behavior and trusted status determine how much protection they provide.
SQL SERVER – 2008 – New DataTypes DATE and TIME
SQL Server 2008 adds separate DATE and TIME datatypes, something DBAs wanted for years. I compare them with the SQL Server 2005 way of using DATETIME.
SQL SERVER – Difference Between Index Rebuild and Index Reorganize Explained with T-SQL Script
Index Rebuild drops and recreates the index, while Index Reorganize reorders the leaf nodes. Rebuild above 40% fragmentation, reorganize between 10% and 40%.
SQL SERVER – Enabling Clustered and Non-Clustered Indexes – Interesting Fact
When enabling clustered and non-clustered indexes, order matters: enabling the clustered index does not enable the others, but rebuilding all indexes does.