An introduction to the Rollup Clause in SQL Server, which aggregates at several levels of a hierarchy. A population table by country, state and city shows how.
Data Mining Algorithms (Analysis Services – Data Mining)
I quite often receive requests for the Data Mining Algorithms details. Book Online has wonderful resources for the same. I suggest to read them here.
geometry STOverlaps: Intersection Alone Is Not Enough
geometry STOverlaps asks a narrower question than whether two shapes share any points. I test equal and contained regions alongside a partial overlap. Those intersecting cases do not all satisfy the method’s overlap definition.
SQL SERVER- IF EXISTS(Select null from table) vs IF EXISTS(Select 1 from table)
Is IF EXISTS(Select null from table) faster than IF EXISTS(Select 1 from table)? A great comment thread by Divya, Brian and Marko answers it.
SQL SERVER – Recompile Stored Procedure at Run Time
Two ways to recompile a stored procedure at run time in SQL Server: add WITH RECOMPILE when you create it, or ask for a one-time recompile.
Mapping MySQL Data Types to SQL Server
Mapping MySQL data types requires checking signed ranges, text encoding, date limits, and application behavior before choosing SQL Server columns.
SQL SERVER – Plan Recompilation and Reduce Recompilation – Performance Tuning
Plan recompilation hurts performance just like a first compile. Learn what causes it, from schema changes to SET options, and how to reduce recompilation.