Sql-server – Tools and techniques for untangling monster views (nested views)

The 2012 Books Online topic "Get Information About a View" states that the permissions required for this specific task are:

• VIEW DEFINITION permission on the database; and
• SELECT permission on sys.sql_expression_dependencies

Note that database-level VIEW DEFINITION is required to allow the user to see information in sys.sql_expression_dependencies; object-level VIEW DEFINITION and SELECT on the DMV will not work (you will receive an empty result set).

Example:

USE Sandpit;
GO
CREATE VIEW dbo.V1 AS SELECT 1 AS const;
GO
CREATE VIEW dbo.V2 AS SELECT v.const FROM dbo.V1 AS v;
GO
CREATE USER Bob WITHOUT LOGIN;

-- These two permissions are not sufficent
GRANT VIEW DEFINITION ON OBJECT::V1 TO Bob;
GRANT VIEW DEFINITION ON OBJECT::V2 TO Bob;

-- This one permission is enough (covers the two above)
GRANT VIEW DEFINITION ON DATABASE::Sandpit TO Bob;

-- Also required
GRANT SELECT ON OBJECT::sys.sql_expression_dependencies TO Bob;
GO
EXECUTE AS USER = 'Bob';
GO
SELECT OBJECT_DEFINITION(OBJECT_ID(N'V1', N'V'));
SELECT OBJECT_DEFINITION(OBJECT_ID(N'V2', N'V'));

-- Show DMV info for the test views
SELECT
    referencing_object_name = OBJECT_NAME(sed.referencing_id),
    sed.referencing_class_desc,
    sed.is_schema_bound_reference,
    sed.referenced_class_desc,
    sed.referenced_schema_name,
    sed.referenced_entity_name
FROM sys.sql_expression_dependencies AS sed
WHERE
    sed.referenced_id = OBJECT_ID(N'dbo.V1', N'V');
GO
REVERT;
GO
DROP USER Bob;
DROP VIEW dbo.V1, dbo.V2;

Regarding sp_depends: that requires only membership of the public role but is deprecated:

This feature will be removed in a future version of Microsoft SQL Server. Avoid using this feature in new development work, and plan to modify applications that currently use this feature. Use sys.dm_sql_referencing_entities and sys.dm_sql_referenced_entities instead.

Looking at the given code, we can say,

• First, this should not be a view but it should be a stored procedure, as it is not just reading from a table, but it uses UDFs.

• Second, the UDF should not be called frequently for the same column. Here, it's called once in the select

  ,dbo.User3StringI18N_KeyValue(b.WKType, b.WKIndex, N'WKS') AS I18NID 
  

  and Second time for joining

  .IETFLangCode = dbo.User3StringI18N_KeyValue(b.WKType, b.WKIndex, N'WKS')
  

One can generate values in a temporary table or use a CTE (Common Table Expression) to get those values in the first place before the join takes place.

I have generated a sample USP that will provide some improvements:

CREATE PROCEDURE usp_UserWKStringI18N
AS
BEGIN
    -- Do operation using UDF 
    SELECT b.WKType
        ,b.WKIndex
        ,dbo.User3StringI18N_KeyValue(b.WKType, b.WKIndex, N'WKS') AS I18NID
        ,dbo.UserI18N_Session_Locale_Key() AS IETFSessionLangCode
        ,dbo.UserI18N_Database_Locale_Key() AS IETFDatabaseLangCode
    INTO #tempTable
    FROM UserWKStringBASE b;

    -- Now final Select
    SELECT b.WKType
        ,b.WKIndex
        ,CASE 
            WHEN ISNULL(il.I18NID, N'') = N''
                THEN id.I18NString
            ELSE il.I18nString
            END AS WKString
        ,CASE 
            WHEN ISNULL(il.I18NID, N'') = N''
                THEN id.IETFLangCode
            ELSE il.IETFLangCode
            END AS IETFLangCode
        ,b.I18NID
        ,b.IETFSessionLangCode
        ,b.IETFDatabaseLangCode
    FROM #tempTable b
    LEFT OUTER JOIN User3StringI18N il
        ON il.I18NID = b.I18NID
            AND il.IETFLangCode = b.IETFSessionLangCode
    LEFT OUTER JOIN User3StringI18N id
        ON id.I18NID = b.I18NID
            AND id.IETFLangCode = b.IETFDatabaseLangCode
END

Please try this