Category: Bad Habits & Best Practices

I show some tricks for getting row counts efficiently, and explain why an accurate row count for a large table is a pipe dream.

I repeat "Bad habits" advice from the past about using statement terminators and schema references to avoid debugging troubles.

I point out that an often-used connection setting, AttachDBFileName, may be the source of many wasted hours of debugging and troubleshooting.

I treat a common scenario: behavior differs between two SQL Server databases that may be the same version, but different compatibility levels.

I discuss the NOLOCK hint in SQL Server, and why you want to avoid slapping it onto every table mentioned in every query.

I discuss ten common cases of misplaced optimization.

I explain why you should avoid helper functions, and join against the catalog views instead.

I provide links to presentations (one with colleague Kevin Kline) at SQL Bits XII.

Last Thursday I presented my "Bad Habits to Kick" presentation at the New England SQL User Group; attached is the slide deck.

By way of an example, see why most of what you hear about SQL Server is only true some of the time, at best.

I see a lot of people suggest while loops instead of cursors in situations where row-based processing is required (or, at least, where folks think that row-based processing is required). Sometimes the justification is...

See why I prefer alias = expression over the more standards-compliant expression AS alias syntax.

See several examples supporting the idea that you should use catalog views, not INFORMATION_SCHEMA, in SQL Server.

Learn why you shouldn't use BETWEEN for date range queries, even with the date data type.

Read about some date/time shorthand you should avoid.

See why you should use sp_executesql instead of EXEC() for running dynamic SQL strings.

See an example that defies a generalization about performance of getting the largest value in a column.

Your naming scheme isn't important, but being consistent is crucial.

In my last post in this series, I talked about problems associated with creating (and using) what I call the "uber-view."  This time, in line with tomorrow's T-SQL Tuesday hosted by Mike Walsh, I...

In my last post in this series, I talked about using ancient copies of Books Online, and why it can be important to keep your local documentation current.  This time I wanted to touch...