数据仓库-拉链算法，如何处理开链、闭链数据

\timing on
set client_encoding='GBK';
/******程序功能说明*********************************//*****以下根据任务不同进行变量设置*****************/SELECT:'AUTO_PDMVIEW' 	AS "PDM_VIEW",:'20230710' 		AS "20230710",:'AUTO_exampleDB' 		AS "example_DATA",:'AUTO_SDATADB' 	AS "SDATA",:'AUTO_exampleVIEW' 	AS "example_VIEW",:'AUTO_ODSVIEW' 	AS "ODS_VIEW",:'AUTOVIEW' 	AS "SUM_VIEW",:'AUTOEVIEW' 	AS "CDE_VIEW"--,'examplesc_read'      AS    "example_DATA"	,:'MAX_DT' 			AS "MAX_DT",:'NULL_DT' 		AS "NULL_DT"
; 
\gset/******以下为程序主体******************************/数据示例：
Start_Dt   End_Dt
20230601  30001231
20230710  30001231 （正常无数据）
20230501  20230710 （正常无数据）DELETE FROM :example_DATA.INT_D_example_ACCT_CAP_CHANGE
WHERE Start_Dt = TO_DATE(:'20230710','YYYYMMDD')
and sys_src='exam';Start_Dt   End_Dt
20230601  30001231
20230501  20230710UPDATE :example_DATA.int_d_example_acct_cap_change
SET End_Dt = TO_DATE('30001231','YYYYMMDD')
WHERE End_Dt = TO_DATE(:'20230710','YYYYMMDD')
and sys_src='exam';Start_Dt   End_Dt
20230601  30001231
20230501  30001231CREATE TEMPORARY TABLE int_d_example_acct_cap_change_ND(LIKE :example_DATA.int_d_example_acct_cap_change INCLUDING DEFAULTS INCLUDING CONSTRAINTS)
ON COMMIT PRESERVE ROWS;INSERT INTO int_d_example_acct_cap_change_ND
(asset_acct
,securities_code,TO_DATE(:'TX_DATE','YYYYMMDD')AS  update_dt,TO_DATE(:'TX_DATE','YYYYMMDD') AS Start_Dt     ,TO_DATE('30001231','YYYYMMDD') AS End_Dt 
)
select COALESCE(TRIM(CAST(A.fundid AS bigint)), '')  asset_acct  ---资金账户
, case when trim(b.belong_exampleflag)='0' then 'E1005731000018' else 'E1013565000016' end as securities_code   ---金融机构编码
from  :ODS_VIEW.ODS_exam_FUNDINFO   A 
left join :CDE_VIEW.examplebroke_branch  B 
on (case  when  TRIM(A.orgid) = '0000' then  'ORG-999'else  COALESCE('ORG-' || TRIM(A.orgid), '')END)=trim(B.branch)WHERE A.Ods_Start_Dt <=:'20230710'AND A.Ods_End_Dt >:'20230710' 
;
-----插入原数据
CREATE TEMPORARY TABLE int_d_example_acct_cap_change_OD(LIKE :example_DATA.int_d_example_acct_cap_change INCLUDING DEFAULTS INCLUDING CONSTRAINTS)
ON COMMIT PRESERVE ROWS;
--插入新数据
CREATE TEMPORARY TABLE int_d_example_acct_cap_change_W_I(LIKE :example_DATA.int_d_example_acct_cap_change INCLUDING DEFAULTS INCLUDING CONSTRAINTS)
ON COMMIT PRESERVE ROWS;----插入更新的数据
CREATE TEMPORARY TABLE int_d_example_acct_cap_change_W_U(LIKE :example_DATA.int_d_example_acct_cap_change INCLUDING DEFAULTS INCLUDING CONSTRAINTS)
ON COMMIT PRESERVE ROWS;把9号全部开链的切片数据插入数据错乱情况：
1、该闭链的开链了，这样的话该条数据取到，但是在处理的时候会被闭链，10号数据里会新增一条，开链
2、该开链的闭链了，这样的话该条数据取不到，10号数据里会新增一条，并且开链
INSERT INTO int_d_example_acct_cap_change_OD
SELECT * FROM :example_DATA.int_d_example_acct_cap_change
WHERE Start_Dt <= TO_DATE(:'20230710','YYYYMMDD')
AND   End_Dt   > TO_DATE(:'20230710','YYYYMMDD')
AND   sys_src='exam'
;全字段找出有变动、或者新增的数据，插入W_I表（比如10号的数据，不在9号的里面），如果数据有减少，则找不出来
INSERT INTO int_d_example_acct_cap_change_W_I
(
asset_acct
,securities_code)
SELECT 
asset_acct
,securities_code   
FROM int_d_example_acct_cap_change_ND
WHERE    sys_src='exam' AND (
COALESCE(asset_acct,'')
,COALESCE( securities_code,''))  NOT IN (SELECT 
COALESCE(asset_acct,'')
,COALESCE( securities_code,'')
FROM int_d_example_acct_cap_change_ODWHERE   sys_src='exam'  )
;找出在9号切片，OD（old）里，但是不在10号ods表中，ND(new)里的数据，找出有变动或者减少的数据
INSERT INTO int_d_example_acct_cap_change_W_U
(
asset_acct
,securities_code 
)
SELECT 
asset_acct
,securities_code
FROM int_d_example_acct_cap_change_OD
WHERE  sys_src='exam' AND (
COALESCE(asset_acct,'')
,COALESCE( securities_code,''))  NOT IN (SELECT 
COALESCE(asset_acct,'')
,COALESCE( securities_code,'')
FROM int_d_example_acct_cap_change_ND
WHERE   sys_src='exam')
;把变动的数据闭链，减少的数据也闭链
UPDATE :example_DATA.int_d_example_acct_cap_change
SET End_Dt = TO_DATE(:'20230710','YYYYMMDD')
WHERE (
COALESCE(asset_acct,'')
,COALESCE( securities_code,'')
) IN (
SELECT 
COALESCE(asset_acct,'')
,COALESCE( securities_code,'')
FROM int_d_example_acct_cap_change_W_U
WHERE  sys_src='exam')
AND Start_Dt <= TO_DATE(:'20230710','YYYYMMDD')
AND End_Dt > TO_DATE(:'20230710','YYYYMMDD')
AND  sys_src='exam'
;插入新增的数据或者有变动的数据（闭链日期已提前置为30001231）INSERT INTO :example_DATA.int_d_example_acct_cap_change
(asset_acct
,securities_code
)
SELECT 
asset_acct
,securities_codeFROM int_d_example_acct_cap_change_W_IWHERE  sys_src='exam'
;/**************************退出主程序****************************/