No indexes, table scans, missing or out of date statistics,
blocking, excess recompilations of stored procedures,
procedures and triggers without SET NOCOUNT ON, poorly
written query with unnecessarily complicated joins, too
much normalization, excess usage of cursors and temporary
tables.


Some of the tools/ways that help you troubleshooting
performance problems are: SET SHOWPLAN_ALL ON, SET
SHOWPLAN_TEXT ON, SET STATISTICS IO ON, SQL Server
Profiler, Windows NT /2000 Performance monitor, Graphical
execution plan in Query Analyzer.