Limit & Offset Using Top - Like MySQL

I have written an SP which allows me to retrieve a specified number of records from an offset I have declared (eg 25 - 50). The SP also allows me to sort the results on any field in either ASC or DESC.

This SP is fairly large / complex and I'm unsure how it will perform.

Can you offer any suggestions as to how performance can be improved... ?



CREATE PROCEDURE usp_GetContactsBasic

      @iUserID int,
      @iOffset int = 0,
      @iLimit int = 10,
      @sOrderField nvarchar(32) = 'contactd_namefirst',
      @bOrderDesc bit = 0

AS

      DECLARE @sExecSQL nvarchar(4000),
            @sParamList nvarchar(4000),
            @iTotalRows int,
            @iRecords int,
            @sOrder1 nvarchar(4),
            @sOrder2 nvarchar(4)

      SET @iTotalRows = @iOffset + @iLimit


      SELECT @sOrder1 = CASE @bOrderDesc
                        WHEN 0 THEN 'ASC'
                        ELSE 'DESC'
                        END

      SELECT @sOrder2 = CASE @bOrderDesc
                        WHEN 0 THEN 'DESC'
                        ELSE 'ASC'
                        END


      SET NOCOUNT ON



      SELECT @iRecords = COUNT(*)
      FROM tbl_companyd CompD INNER JOIN
            tbl_companym CompM ON CompD.companyd_companymid = CompM.companym_id INNER JOIN
            tbl_contactm ContM ON CompD.companyd_id = ContM.contactm_companydid INNER JOIN
            tbl_contactd ContD ON ContM.contactm_id = ContD.contactd_contactmid AND
            (ContD.contactd_changetype = 1 OR ContD.contactd_changetype = 3) INNER JOIN
            tbl_country Ctry ON ContM.contactm_countryid = Ctry.country_id
      WHERE ContM.contactm_countryid IN
            (SELECT Ctry2.country_id
            FROM tbl_user Usr2
                  INNER JOIN tbl_access Acc2 ON Usr2.user_id = Acc2.access_userid
                  INNER JOIN tbl_country Ctry2 ON Acc2.access_countryid = Ctry2.country_id
            WHERE Usr2.user_id = @iUserID)


      SELECT @iRecords [COUNT]



      If @iTotalRows > @iRecords
            BEGIN
                  SET @iTotalRows = @iRecords
                  SET @iLimit = @iRecords - @iOffset
            END


      IF @iLimit < 0
            BEGIN
                  SET @iLimit = 0
                  SET @iTotalRows = 0
            END



      SET
             @sExecSQL = N'SELECT * FROM ('
                  + N'      SELECT TOP ' + CAST(@iLimit AS nvarchar(16)) + ' * FROM ('
                  + N'            SELECT TOP ' + CAST(@iTotalRows AS nvarchar(16)) + ' '
                  + N'                  CompM.companym_name, '
                  + N'                  ContD.contactd_namefirst, '
                  + N'                  ContD.contactd_namelast, '
                  + N'                  ContD.contactd_email,  '
                  + N'                  Ctry.country_full, '
                  + N'                  ContM.contactm_id, '
                  + N'                  ContM.contactm_changemade '
                  + N'            FROM tbl_companyd CompD INNER JOIN '
                  + N'                  tbl_companym CompM ON CompD.companyd_companymid = CompM.companym_id INNER JOIN '
                  + N'                  tbl_contactm ContM ON CompD.companyd_id = ContM.contactm_companydid INNER JOIN '
                  + N'                  tbl_contactd ContD ON ContM.contactm_id = ContD.contactd_contactmid AND '
                  + N'                  (ContD.contactd_changetype = 1 OR ContD.contactd_changetype = 3) INNER JOIN '
                  + N'                  tbl_country Ctry ON ContM.contactm_countryid = Ctry.country_id '
                  + N'            WHERE ContM.contactm_countryid IN '
                  + N'                  (SELECT Ctry2.country_id '
                  + N'                  FROM tbl_user Usr2 '
                  + N'                        INNER JOIN tbl_access Acc2 ON Usr2.user_id = Acc2.access_userid '
                  + N'                        INNER JOIN tbl_country Ctry2 ON Acc2.access_countryid = Ctry2.country_id '
                  + N'                  WHERE Usr2.user_id = @iUserID '
                  + N'                  )'
                  + N'            ORDER BY ' + @sOrderField + ' ' + @sOrder1 + ', contactm_id ' + @sOrder1 + ') [First]'
                  + N'      ORDER BY ' + @sOrderField + ' ' + @sOrder2 + ', contactm_id ' + @sOrder2 + ') [Second]'
                  + N'ORDER BY ' + @sOrderField + ' ' + @sOrder1 + ', contactm_id ' + @sOrder1



      SET
            @sParamList = N'@iUserID int'


      EXEC sp_executesql
            @stmt            = @sExecSQL,
            @params            = @sParamList,
            @iUserID      = @iUserID

      
      SET NOCOUNT OFF

GO


DROP PROCEDURE usp_GetContactsBasic


EXEC usp_GetContactsBasic 1, 0, 10, 'companym_name', 0