I suggest a different tack altogether. Instead of naming 18,000 parameters why not make use of table-valued parameters? I'm making some leaps here about what exactly you're using all these parameters for (since you so handily anonymized them for us :-)), but if you create these types:
CREATE TYPE dbo.VarcharParameters AS TABLE
(
ParamName SYSNAME,
ParamValue VARCHAR(100)
);
CREATE TYPE dbo.BitParameters AS TABLE
(
ParamName SYSNAME,
ParamValue BIT
);
Then change the procedure as follows (please note the comments inline about how to deal with stuff in the TVPs):
CREATE PROCEDURE dbo.ObviouslyAnonymizedProcedure2
@SchemaID INT = NULL,
@TypeDesc NVARCHAR(60) = NULL,
@VCParams dbo.VarcharParameters READONLY,
@BitParams dbo.BitParameters READONLY,
@paramStartRow INT,
@paramMaxRows INT
AS
BEGIN
SET NOCOUNT ON;
SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED;
DECLARE
@sql NVARCHAR(MAX) = N'',
@From NVARCHAR(MAX) = N'',
@Where NVARCHAR(MAX) = N'',
@LF CHAR(2) = CHAR(13) + CHAR(10),
@Tab CHAR(1) = CHAR(9),
@FLOuter NVARCHAR(MAX),
@FLInner NVARCHAR(MAX);
DECLARE @LFTab CHAR(3) = @LF + @Tab;
SET @FLOuter = @LFTab + ' t1.name'
+ @LFTab + ', t1.object_id'
+ @LFTab + ', SCHEMA_NAME(t1.schema_id) AS schema_name'
+ @LFTab + ', t1.type_desc'
+ @LF;
SET @FLInner = @LFTab + ' t0.name'
+ @LFTab + ', t0.object_id'
+ @LFTab + ', t0.schema_id'
+ @LFTab + ', t0.type_desc'
+ @LF;
SET @From = N' From sys.objects as t0 with(nolock) ' + @LF;
IF @SchemaId IS NOT NULL
BEGIN
SET @Where = @Where + ' AND t0.schema_id = @SchemaId';
END
IF @TypeDesc IS NOT NULL
BEGIN
SET @Where = @Where + ' AND t0.type_desc = @TypeDesc'
END
-- obviously you need a bunch more of these, and I'm making
-- a half-educated guess about how the bit params are used:
IF EXISTS (SELECT 1 FROM @BitParams WHERE ParamName = 'paramIsView' AND ParamValue = 1)
BEGIN
SET @Where += ' AND t0.type_desc = ''VIEW'''
END
-- and I'm not clear exactly what you're doing with the varchar params,
-- but if you give some more clues I'm sure we can work that out too.
-- It may be very simple to build a string from those, without having to
-- reference every single one of them by name, depending on what they do.
SET @sql = 'SELECT ' + @FLOuter + ' FROM ( SELECT ROW_NUMBER() OVER
(ORDER BY t0.[object_id]) AS rn, ' + @FLInner +
@From + ' WHERE 1 = 1 ' + @Where + ') AS t1
WHERE t1.rn BETWEEN @paramStartRow + 1
AND @paramStartRow + @paramMaxRows ORDER BY rn;'
EXEC sp_executesql @sql,
N'@SchemaId INT,@TypeDesc NVARCHAR(60),@paramStartRow INT,@paramMaxRows INT',
@SchemaID, @TypeDesc, @paramStartRow, @paramMaxRows;
END
GO
Now you can call it like this:
DECLARE @x dbo.VarcharParameters;
INSERT @x VALUES
('paramFoo', 'wuzzuh'),
('paramGamma', 'foobar');
DECLARE @y dbo.BitParameters;
INSERT @y VALUES
('paramIsView', 0),
('paramIsTable', 0);
EXEC dbo.ObviouslyAnonymizedProcedure2
@SchemaId = 1,
@TypeDesc = NULL,
@VCParams = @x,
@BitParams = @y,
@paramStartRow = 1,
@ParamMaxRows = 20;
I won't show my results, because they'll be different from yours, but I bet the massive reduction in parameters will eliminate the compilation problems you have.
Also this is how you call this procedure from T-SQL; in order to call it from, say, C#, you'll need to use a DataTable or List or something compatible. I have an example here.
This is also much more flexible in terms of adding new parameters - you don't have to change the interface to the stored procedure, just add them to the procedure body (where relevant) and to the code that populates the data table.
Now just fill us in on what all the varchar parameters do and you might be one step closer to a solution. :-)
Best Answer
'This'
is avarchar
string.N'This'
is annvarchar
string.I'll guess that, after
@tblUpdateStats_List
, the remainder of your string was more than 4000 characters.I did some experiments (in SQL 2016), and it looks like when a
varchar
string is implicitly converted tonvarchar
, it is converted tonvarchar(4000)
, notnvarchar(MAX)
.I ran the following query:
With
<literal>
initially being an nvarchar string constructed as follows:This string was 4,138 characters long (on Windows, where EOL is CR+LF), so the total string length should have been 3 + 7000 + 4138 + 3, or 11,144 characters
When run with the literal as an
nvarchar
string, got the following results:So, correct length, and expected values at end of replicated string, at start of literal, and at end of literal.
Then, I changed the literal to a
varchar
string, and got this:So, length shows 3 + 7000 + 4000 + 3 = 11006 - what we'd expect if the varchar value was truncated down to just 4,000 characters. And, we don't see
XXX
before the finalQQQ
, also as we'd expect under these circumstances.FYI - If I
CAST
thevarchar
literal tonvarchar(MAX)
, my results went back to the first ones, so an explicit cast avoids this problem.