Using linked servers, OPENROWSET and OPENQUERY

BuckWoody — Tue, 16 Mar 2010 12:41:33 GMT

SQL Server has a few mechanisms to reach out to another server (even another server type) and query data from within a Transact-SQL statement. Among them are a set of stored credentials and information (called a Linked Server), a statement that uses a linked server called called OPENQUERY, another called OPENROWSET, and one called OPENDATASOURCE. This post isn’t about those particular functions or statements – hit the links for more if you’re new to those topics.

I’m actually more concerned about where I see these used than the particular method. In many cases, a Linked server isn’t another Relational Database Management System (RDMBS) like Oracle or DB2 (which is possible with a linked server), but another SQL Server. My concern is that linked servers are the new Data Transformation Services (DTS) from SQL Server 2000 – something that was designed for one purpose but which is being morphed into something much more.

In the case of DTS, most of us turned that feature into a full-fledged job system. What was designed as a simple data import and export system has been pressed into service doing logic, routing and timing. And of course we all know how painful it was to move off of a complex DTS system onto SQL Server Integration Services.

In the case of linked servers, what should be used as a method of running a simple query or two on another server where you have occasional connection or need a quick import of a small data set is morphing into a full federation strategy. In some cases I’ve seen a complex web of linked servers, and when credentials, names or anything else changes there are huge problems.

Now don’t get me wrong – linked servers and other forms of distributing queries is a fantastic set of tools that we have to move data around. I’m just saying that when you start having lots of workarounds and when things get really complicated, you might want to step back a little and ask if there’s a better way. Are you able to tolerate some latency? Perhaps you’re able to use Service Broker. Would you like to be platform-independent on the data source? Perhaps a middle-tier might make more sense, abstracting the queries there and sending them to the proper server. Designed properly, I’ve seen these systems scale further and be more resilient than loading up on linked servers.

Tools and Processes for “Fitting it all in”

BuckWoody — Mon, 18 Jan 2010 14:42:05 GMT

Most data professionals I’ve met work in two modes: we plan for our day, and we react to the situations around us. I’m staring at my list of things that I need to do today right now, which is my planned work. Of course, I have no idea how much of that will really get done – it’s optimistic to be sure. On the other hand I have several systems I manage, and at any moment one of them or the people that interface with them may “change state” such that I need to give them some attention.

So how do I meld the two? Sometimes it can be quite difficult. I’m constantly working through my list in my mind, re-arranging what I’m focusing on based on what I perceive as the highest need. There are, however, some tools that I use each day to help me manage the workflow.

I use Outlook for tracking everything, since it has a task list (my primary tracking), a calendar, mail and so on. Also I can share the information, it’s on-line so I can see it anywhere, and I can even take it offline onto the plane this week when I fly out of town.

For the “ad-hoc” work, I rely on a script library, which I keep as SQL Server Management Studio projects. I keep those scripts and projects backed using Microsoft Live Mesh, which synchronizes those files (along with a few other critical files and my IE Favorites) across not only my laptop and primary systems, but even with my Virtual Machines.

Also for my SQL Server systems I use the Standard Reports I’ve blogged about here. I also use Greg Larsen’s Database Dashboard, and a series of PowerShell scripts that work across my systems, alerting me to any problems. Of course I’m using SQL Server Agent Jobs quite a bit, and I also use Alerts and some Perfmon automation for my monthly baselining.

So – is this your experience as well? Do you get driven by both planned and unplanned work? What tools and processes do you use to keep it all straight with your SQL Server Instances?

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Using linked servers, OPENROWSET and OPENQUERY

Tools and Processes for “Fitting it all in”