对于1000万条记录，Sql更新需要4天

Question

我想更新一个临时表中有超过1000万条记录的数据库表。但我的更新查询执行超过4天。

1.）我已经为tax_ledger_item_tab创建了更新搜索条件的索引。在party_type，identity，company上创建的索引。我的搜索条件在party_type，identity，company，delivery_type_id上​​作为以下给定查询，这些列不是表中的键。

我相信我不能为索引添加传递type_id，因为它将通过查询更新，如果我将其添加到索引性能将是最糟糕的。

2.）临时表identity_invoice_info_cfv也将返回70,000条记录。

到目前为止，我相信我的更新执行计划成本将大约为70000 * 1000万条记录。

如何通过以下更新查询获得性能增强？我只想更新delivery_type_id，仅提取列。

DECLARE

CURSOR get_records IS
  SELECT i.COMPANY, i.IDENTITY, i.CF$_DELIVERY_TYPE
    FROM identity_invoice_info_cfv i
   WHERE i.PARTY_TYPE_DB = 'CUSTOMER';

BEGIN

  FOR rec_ IN get_records LOOP
  dbms_output.put_line  (sysdate ); 

    UPDATE tax_ledger_item_tab t
       SET t.delivery_type_id = rec_.CF$_DELIVERY_TYPE, t.fetched = 'TRUE'
     WHERE t.party_type = 'CUSTOMER'
       AND t.identity = rec_.IDENTITY
       AND t.company = rec_.COMPANY
       AND t.delivery_type_id IS NULL;

    COMMIT;  

  END LOOP;

 END;

Answer 1

使用MERGE声明：

Oracle安装程序：

CREATE TABLE identity_invoice_info_cfv ( COMPANY, IDENTITY, CF$_DELIVERY_TYPE, PARTY_TYPE_DB ) AS
SELECT 'A', 123, 456, 'CUSTOMER' FROM DUAL;

CREATE TABLE tax_ledger_item_tab ( identity, company, party_type, delivery_type_id, fetched ) AS
SELECT 123, 'A', 'CUSTOMER', CAST( NULL AS NUMBER ), 'FALSE' FROM DUAL;

合并：

MERGE INTO tax_ledger_item_tab t
USING identity_invoice_info_cfv i
ON (
    t.identity      = i.identity
AND t.company       = i.COMPANY
AND t.party_type    = 'CUSTOMER'
AND i.PARTY_TYPE_DB = 'CUSTOMER'
)
WHEN MATCHED THEN
  UPDATE
  SET delivery_type_id = i.CF$_DELIVERY_TYPE,
      fetched          = 'TRUE'
  WHERE t.delivery_type_id IS NULL;

查询：

SELECT * FROM tax_ledger_item_tab;

输出：

IDENTITY | COMPANY | PARTY_TYPE | DELIVERY_TYPE_ID | FETCHED
-------: | :------ | :--------- | ---------------: | :------
     123 | A       | CUSTOMER   |              456 | TRUE   

db <>小提琴here

Answer 2

我希望你也可以使用Merge Statement来实现这一目标。下面是相同的代码。请从您身边测试一些样本数据，然后继续。

  Merge into tax_ledger_item_tab t
  using identity_invoice_info_cfv i
      on (t.party_type ='CUSTOMER' and t.identity=i.IDENTITY 
         and t.company = i.COMPANY  and i.PARTY_TYPE_DB = 'CUSTOMER')
       when matched then
             update set  
              t.delivery_type_id=i.CF$_DELIVERY_TYPE,
              t.fetched = 'TRUE' 
            where t.delivery_type_id IS NULL;
        commit;