An ETL process finishes without an exception — but was everything really loaded that should have been? The mere fact that a process did not abort says nothing about whether it actually did what was expected of it. A readable, evaluable log is what turns a gut feeling into a defensible statement. This design pattern … Read more
Three ways to model the same ETL task in SSIS. One takes 10 minutes and is straightforward. One takes hours, 40 Data Flow Tasks, and won’t survive the next requirements change. The question “how much SQL belongs in an SSIS package?” decides maintainability, readability, and development speed — not tool loyalty. What you’ll take away: … Read more
Diff two versions of an SSIS package — even a trivial rename produces eight “changed regions” in the XML, and the diff doesn’t even locate the actual edit correctly. The same modification in a stored procedure shows three lines of diff, reviewable in 30 seconds. Source code management is a maintainability decision — not a … Read more
A SQL Server Agent job that needs to read from a file share fails with Login failed — the agent’s service account has no permission there. The solution is impersonation at runtime, configured in SQL Server Agent through a proxy user. One dead end remains: plain Transact-SQL Script steps don’t support impersonation — the workaround is to wrap the T-SQL in an … Read more
SSIS, T-SQL, or a combination of both? There is no single right answer. What there is, is a handful of decision criteria against which every concrete choice — technology and extent of use — should be measured: readability, source code management, impersonation. This article series takes these three axes and delivers a concrete argument per axis. Anyone arguing ETL … Read more
Anyone who writes a 200-line SELECT with a recursive CTE understands it completely while writing it — and three weeks later, not a word of it. Inline comments are the safety net against that. The problem: placed badly, they destroy the very readability they are meant to preserve. What this article covers: Prerequisite: The examples run against AdventureWorksDW2017 (table [dbo].[DimEmployee], a … Read more
An SSIS package fails, you open the execution log to find the cause — and face a tree in which the tasks don’t appear in the order they ran, but alphabetically by name. For complex packages that log is simply unreadable. The good news: a well-thought-out naming convention solves the problem completely — without any … Read more
If you can’t tell at a glance where the WHERE clause of a 200-line SELECT statement starts and ends, you have a structure problem — not a content problem. This article shows the layout that keeps long statements navigable. → Part of a series. This is part 2 and covers statement structure (SELECT, WHERE, FROM, JOIN). The basics for identifiers, delimiters, commas, and aliases are … Read more
Anyone who has ever had to debug a badly or completely unformatted SELECT with 30 columns and half a dozen joins knows the feeling: it isn’t the SQL that eats up your day — it’s hunting down what the statement is actually trying to do. SQL formatting isn’t a matter of taste; it’s a maintenance … Read more
A SQL statement that looks neatly indented on one developer’s machine collapses into a staircase on a colleague’s — even though nobody touched the code. The culprit is almost always a difference in editor settings: a different tab width, tabs instead of spaces, a non-monospaced font. Readable SQL code in a team doesn’t start with … Read more
