No query plan for procedure in SQL Server 2005 - sql

Question

We have a SQL Server DB with 150-200 stored procs, all of which produce a viewable query plan in sys.dm_exec_query_plan except for one. According to http://msdn.microsoft.com/en-us/library/ms189747.aspx:
Under the following conditions, no Showplan output is returned in the query_plan column of the returned table for sys.dm_exec_query_plan:
If the query plan that is specified by using plan_handle has been evicted from the plan cache, the query_plan column of the returned table is null. For example, this condition may occur if there is a time delay between when the plan handle was captured and when it was used with sys.dm_exec_query_plan.
Some Transact-SQL statements are not cached, such as bulk operation statements or statements containing string literals larger than 8 KB in size. XML Showplans for such statements cannot be retrieved by using sys.dm_exec_query_plan unless the batch is currently executing because they do not exist in the cache.
If a Transact-SQL batch or stored procedure contains a call to a user-defined function or a call to dynamic SQL, for example using EXEC (string), the compiled XML Showplan for the user-defined function is not included in the table returned by sys.dm_exec_query_plan for the batch or stored procedure. Instead, you must make a separate call to sys.dm_exec_query_plan for the plan handle that corresponds to the user-defined function.
And later..
Due to a limitation in the number of nested levels allowed in the xml data type, sys.dm_exec_query_plan cannot return query plans that meet or exceed 128 levels of nested elements.
I'm confident that none of these apply to this procedure. The result never has a query plan, no matter what the timing, so 1 doesn't apply. There are no long string literals or bulk operations, so 2 doesn't apply. There are no user defined functions or dynamic SQL, so 3 doesn't apply. And there's little nesting, so the last doesn't apply. In fact, it's a very simple proc, which I'm including in full (with some table names changed to protect the innocent). Note that the parameter-sniffing shenanigans postdate the problem. It still happens even if I use the parameters directly in the query. Any ideas on why I don't have a viewable query plan for this proc?
ALTER PROCEDURE [dbo].[spGetThreadComments]
#threadId int,
#stateCutoff int = 80,
#origin varchar(255) = null,
#includeComments bit = 1,
#count int = 100000
AS
if (#count is null)
begin
select #count = 100000
end
-- copy parameters to local variables to avoid parameter sniffing
declare #threadIdL int, #stateCutoffL int, #originL varchar(255), #includeCommentsL bit, #countL int
select #threadIdL = #threadId, #stateCutoffL = #stateCutoff, #originL = #origin, #includeCommentsL = #includeComments, #countL = #count
set rowcount #countL
if (#originL = 'Foo')
begin
select * from FooComments (nolock) where threadId = #threadId and statusCode <= #stateCutoff
order by isnull(parentCommentId, commentId), dateCreated
end
else
begin
if (#includeCommentsL = 1)
begin
select * from Comments (nolock)
where threadId = #threadIdL and statusCode <= #stateCutoffL
order by isnull(parentCommentId, commentId), dateCreated
end
else
begin
select userId, commentId from Comments (nolock)
where threadId = #threadIdL and statusCode <= #stateCutoffL
order by isnull(parentCommentId, commentId), dateCreated
end
end

Answer 1

Hmm, perhaps the tables aren't really tables. They could be views or something else.

Answer 2

try putting dbo. or whatever the schema is in front of all of the table names, and then check again.
see this article:
http://www.sommarskog.se/dyn-search-2005.html
quote from the article:
As you can see, I refer to all tables
in two-part notation. That is, I also
specify the schema (which in SQL
7/2000 parlance normally is referred
to as owner.) If I would leave out the
schema, each user would get his own
his own private version of the query
plan