Что делает данная процедура?

EXEC sp_executesql N'CREATE OR ALTER PROCEDURE dbo.ttn_prixDEL
@tpNo AS VARCHAR(20),
@retVal AS BIT OUTPUT  
AS
DECLARE @id_mat AS INT, @prCnt AS NUMERIC(10,2), @oCnt AS NUMERIC(10,2);
 
SET @retVal = 1;
 
 
DECLARE cur CURSOR SCROLL READ_ONLY LOCAL FOR
    SELECT p.id_mat, p.prCnt, p.prPrice
FROM prix p
WHERE p.tpNo = @tpNo;
 
OPEN cur
 
FETCH NEXT FROM cur INTO @id_mat, @prCnt 
WHILE @@FETCH_STATUS = 0 BEGIN
 
    SELECT @oCnt = oCnt 
FROM rest 
WHERE id_mat = @id_mat;
 
IF @prCnt > @oCnt
SET @retVal = 0;
 
    FETCH NEXT FROM cur INTO @id_mat, @prCnt
END
 
IF @retVal = 1 BEGIN
BEGIN TRY
    BEGIN TRANSACTION
FETCH FIRST FROM cur INTO @id_mat, @prCnt
WHILE @@FETCH_STATUS = 0 BEGIN
 
    SELECT @oCnt = oCnt 
FROM rest 
WHERE id_mat = @id_mat 
 
UPDATE rest SET 
oCnt = oCnt - @prCnt
WHERE id_mat = @id_mat 
 
    FETCH NEXT FROM cur INTO @id_mat, @prCnt
END
        
DELETE FROM prix WHERE tpNo = @tpNo;
 
DELETE FROM ttn_prix WHERE tpNo = @tpNo;
 
    COMMIT TRANSACTION
END TRY
BEGIN CATCH
    PRINT 
        ''Error '' + CONVERT(varchar(50), ERROR_NUMBER()) +
        '', Severity '' + CONVERT(varchar(5), ERROR_SEVERITY()) +
        '', State '' + CONVERT(varchar(5), ERROR_STATE()) +
        '', Line '' + CONVERT(varchar(5), ERROR_LINE())
 
    PRINT ERROR_MESSAGE();
 
    IF XACT_STATE() <> 0 BEGIN
        ROLLBACK TRANSACTION
    END
END CATCH;
END;
 
CLOSE cur
DEALLOCATE cur
'
GO