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【DM版本】:dm8
【操作系统】：
【CPU】:
【问题描述】*：
数据量整体不大，1w条以内。正常查询速度非常快，1s内出来。但是加入排序之后查询需要40s左右。
sql如下：

	SELECT
		T.*
	FROM
		(
		SELECT
			K.*,
			TCS.TESTCATEGORY,
			TCS.SEGMENTNAME TESTTYPE,
			TCS.SAMPLENATURE
		FROM
			(
			SELECT
				L.TESTNAME TESTNAME,
				L.ID LIMSTESTID,
				L.ID TESTID,
				L.ID,
				L.COMPANY,
				concat_ws(' ',
				B.STDCODE,
				B.STANDSRDNAME) STDCODENAME,
				concat_ws(' ',
				A.SECTNO,
				A.SECTNAME) SECNONAME,
				A.ID METHODSECTIONID,
				A.REPORTNAME REPORTNAME,
				A.METHODNAME METHODNAME,
				A.SECTNO SECTNO,
				A.SECTNAME SECTNAME,
				B.STANDSRDNAME STANDSRDNAME,
				B.STDCODE ,
				L.TESTCATSEGMENTID,
				R.ORGID,
				R.ORGNAME,
				R.ID AS METHODRELATEDTOTEST,
				R.TMPLELNID,
				R.TMPLELNNAME,
				R.FULLNAME,
				R.FULLCODE,
				R.CHECKFULLCODE,
				R.CHECKFULLNAME,
				R.SHOWPADFLAG,
				R.CONTROLNO AS TESTCONTROLNO
			FROM
				(
				SELECT
					*
				FROM
					T_LIMS_METHODRELATEDTOTEST mrt
				WHERE
					(mrt.DEFAULTMETHODFLAG = '1'
						OR NOT EXISTS (
						SELECT
							testid
						FROM
							T_LIMS_METHODRELATEDTOTEST sub
						WHERE
							DEFAULTMETHODFLAG = '1'
							AND mrt.TESTID = sub.TESTID ) )
					AND mrt.ACTIVATEDFLAG = 1 ) R
			LEFT JOIN T_LIMS_METHOD_SECTION A ON
				R.SECTIONID = A.ID
			LEFT JOIN T_LIMS_METHOD B ON
				A.METHODID = B.ID
			LEFT JOIN T_LIMS_TEST L ON
				R.TESTID = L.ID
			INNER JOIN (
				SELECT
					METHODRELATEDTOTESTID,
					MAX(DISPLAYFLAG)
				FROM
					t_lims_analyte
				WHERE
					DISPLAYFLAG = 1
				GROUP BY
					METHODRELATEDTOTESTID ) analyte ON
				analyte.METHODRELATEDTOTESTID = R.ID
			WHERE
				L.ID IS NOT NULL
				AND L.ACTIVATEDFLAG = 1 ) K
		LEFT JOIN T_LIMS_TESTCATSEGMENT TCS ON
			TCS.ID = K.TESTCATSEGMENTID ) T
	WHERE
		( "COMPANY" = 'FDAF' )
		AND EXISTS (
		SELECT
			1
		FROM
			T_LIMS_TESTCATSEGMENTDEPT TSD
		WHERE
			TSD.TESTCATSEGMENTID = T.TESTCATSEGMENTID
			AND EXISTS (
			SELECT
				1
			FROM
				(
				SELECT
					up_.*
				FROM
					T_CORE_USER_PERMISSION UP_
				WHERE
					UP_.USERID = 'admin'
					AND UP_.PERMISSIONTYPEID = 'T_CORE_ORG') U
			LEFT JOIN T_CORE_ORG O_ ON
				O_.ID = U.TARGETID
			WHERE
				(O_.ID = TSD.CORPID
					OR EXISTS (
					SELECT
						1
					FROM
						T_CORE_ORG O1
					WHERE
						O1.ID = TSD.CORPID
						AND O1.PARENTID = O_.ID)
					OR (EXISTS (
					SELECT
						1
					FROM
						T_CORE_ORG O1
					WHERE
						O1.ID = TSD.CORPID
						AND O1.ID = O_.PARENTID )
					AND O_.ORGCATEGORY = '3') )
				AND O_.PARENTID IS NOT NULL) )
	ORDER BY
		SAMPLENATURE

执行计划如下：