How to improve the search speed when using left join SQL Server? - sql

Question

In SQL Server, I query data from two VIEW to get records whose OLDPID are -1,-2:
SELECT
T1.*, T2.LEAF
FROM
(SELECT *
FROM VIEW_OBJECT_TREE_DATA
WHERE OLDPID IN (-1, -2)) T1
LEFT JOIN
VIEW_OBJECT_TREE_DATA_GROUP T2 ON T1.NODEID = T2.NODEPID
WHERE
T1.STATE = 1
But it takes 3-4 seconds to get the result.
How can I modify this SQL query to improve its speed?
VIEW_OBJECT_TREE_DATA has OLDPID, OLDID and NAME columns with 450000 records.VIEW_OBJECT_TREE_DATA_GROUP has NODEPID and LEAF with 65000 records.
Below is some sql of view and function:
VIEW_OBJECT_TREE_DATA:
CREATE VIEW dbo.VIEW_OBJECT_TREE_DATA
AS
SELECT(SELECT[dbo].[FNNC_GET_TREE_GUID](0, OBJECT_ID)) AS NODEID,
(SELECT[dbo].[FNNC_GET_TREE_GUID](0, PARENT_ID)) AS NODEPID, 'MY_OBJECT_TABLE' AS[TABLE],
OBJECT_ID AS OLDID, PARENT_ID AS OLDPID, OBJECT_NAME COLLATE DATABASE_DEFAULT AS NAME,
OBJECT_CODE COLLATE database_default AS CODE, OBJECT_TYPE COLLATE database_default AS TYPE,
OBJECT_STATE as STATE
FROM dbo.MY_OBJECT_TABLE
WHERE OBJECT_STATE <> -1
UNION
SELECT(SELECT[dbo].[FNNC_GET_TREE_GUID](1, INDICATOR_ID)) AS NODEID,
(SELECT[dbo].[FNNC_GET_TREE_GUID](0, OBJECT_ID)) AS NODEPID, 'MY_INDICATOR_TABLE' AS[TABLE],
INDICATOR_ID AS OLDID, OBJECT_ID AS OLDPID, INDICATOR_NAME COLLATE DATABASE_DEFAULT AS NAME,
INDICATOR_CODE COLLATE database_default AS CODE, INDICATOR_TYPE COLLATE database_default AS TYPE,
INDICATOR_STATE AS STATE
FROM dbo.MY_INDICATOR_TABLE
WHERE INDICATOR_STATE <> -1
VIEW_OBJECT_TREE_DATA_GROUP :
CREATE VIEW VIEW_OBJECT_TREE_DATA_GROUP
AS
SELECT NODEPID,COUNT(0) AS LEAF FROM VIEW_OBJECT_TREE_DATA GROUP BY NODEPID
Function:
USE[MY_DATABASE]
GO
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER FUNCTION[dbo].[FNNC_GET_TREE_GUID](#TYPE INT, #ID INT)
RETURNS UNIQUEIDENTIFIER
AS
BEGIN
RETURN CAST(CAST(#TYPE AS binary(4))+CAST(#ID AS varbinary(28)) AS UNIQUEIDENTIFIER)
END

Answer 1

You can directly join those two views without having to use a subquery.
select TD.*, DG.LEAF
from VIEW_OBJECT_TREE_DATA as TD
left join VIEW_OBJECT_TREE_DATA_GROUP as DG on DG.NODEPID = TD.NODEID
where TD.OLDPID in (-1, -2) and
TD.STATE = 1
Although without seeing those views and the execution plan there is no way of knowing what slows you down.