Accessing linked servers dynamically

We have a view in one database that consists of the union of all the
rows in a set of tables located on a number of remote linked servers.
If I hard-code the remote server names in the view, it will fail if
any of the remote servers is unavailable. To make this more robust, I
would like it to only query those servers which are available. So I am
maintaining a list of available servers in a table in my main
database. My idea then is to replace the view with a function that
returns a table variable. This function will query all the remote
servers that are available, inserting rows into the table variable.
So within the function I have to generate a piece of dynamic SQL (in
the format 'SELECT ... FROM server.database.dbo.table') to access the
linked server. This works fine, but I can't find a way to get the
results of this query into my table variable. If I run a piece of
dynamic SQL with 'INSERT INTO @.tablevariable' it won't work because
the scope of the dynamic SQL is outside the scope of the function. And
if I use a temporary table I'll get concurrency problems. I have tried
using OPENQUERY and OPENROWSET, but it seems you can't pass string
variables as the parameters to either of these, so effectively I'm
back to hard-coding the server names.
So my question is (finally!): Does anyone know of a way to access a
linked server whose name I have in a string without using dynamic SQL?
Or is there a better way to achieve this?
Thanks in advance!James,
variable would not qualify as table name in a query, whether that variable
represents a local or linked server.
A way around for your situation may be using global temp table. It's not
that much different from a variable, in some situation offers more and in
others less advantage.
hth
Quentin
"James Bosworth" <james.bosworth@.triadgroup.plc.uk> wrote in message
news:1967a78c.0307250500.68dc377e@.posting.google.com...
> We have a view in one database that consists of the union of all the
> rows in a set of tables located on a number of remote linked servers.
> If I hard-code the remote server names in the view, it will fail if
> any of the remote servers is unavailable. To make this more robust, I
> would like it to only query those servers which are available. So I am
> maintaining a list of available servers in a table in my main
> database. My idea then is to replace the view with a function that
> returns a table variable. This function will query all the remote
> servers that are available, inserting rows into the table variable.
> So within the function I have to generate a piece of dynamic SQL (in
> the format 'SELECT ... FROM server.database.dbo.table') to access the
> linked server. This works fine, but I can't find a way to get the
> results of this query into my table variable. If I run a piece of
> dynamic SQL with 'INSERT INTO @.tablevariable' it won't work because
> the scope of the dynamic SQL is outside the scope of the function. And
> if I use a temporary table I'll get concurrency problems. I have tried
> using OPENQUERY and OPENROWSET, but it seems you can't pass string
> variables as the parameters to either of these, so effectively I'm
> back to hard-coding the server names.
> So my question is (finally!): Does anyone know of a way to access a
> linked server whose name I have in a string without using dynamic SQL?
> Or is there a better way to achieve this?
> Thanks in advance!