插入超过 40k+ 行时如何提高性能

Question

CREATE TABLE new_details_staging 
(
    e_id         NUMBER(10),
    e_name       VARCHAR2(30),
    portal_desc  VARCHAR2(50),
    risk_dec     VARCHAR2(50),
    CONSTRAINT pk_new_details_staging PRIMARY KEY (e_id)
);

INSERT INTO new_details_staging 
VALUES (11, 'A', 'AA', 'High');

INSERT INTO new_details_staging 
VALUES (22, 'B', 'BB', 'Low');

CREATE TABLE lookup_ref 
(
    ref_id       NUMBER(10),
    ref_typ      VARCHAR2(30),
    ref_typ_desc VARCHAR2(20),
    CONSTRAINT pk_lookup_ref PRIMARY KEY (ref_id)
);

INSERT INTO lookup_ref 
VALUES (181, 'portal', 'AA');

INSERT INTO lookup_ref 
VALUES (182, 'portal', 'BB');

INSERT INTO lookup_ref 
VALUES (183, 'risk', 'High');

INSERT INTO lookup_ref 
VALUES (184, 'risk', 'Low');

CREATE TABLE new_details_main 
(
    e_id    NUMBER(10),
    e_name  VARCHAR2(30),
    portal  NUMBER(20),
    risk    NUMBER(20),
    CONSTRAINT pk_new_details_main PRIMARY KEY (e_id)
);

COMMIT;

我的尝试：

INSERT INTO new_details_main (e_id, e_name, portal,risk)
    SELECT  
        n.e_id,
        n.e_name,
        (SELECT lr.ref_id
         FROM lookup_ref lr
         WHERE lr.ref_typ = 'portal'
           AND lr.ref_typ_desc = n.portal_desc),
        (SELECT lr.ref_id
         FROM lookup_ref lr
         WHERE lr.ref_typ = 'risk'
           AND lr.ref_typ_desc = n.risk_dec)
    FROM    
        new_details_staging n;

目前，我正在插入一些记录，它给出了准确的结果，但实际上，有 40k+ 条记录，所以我相信它也会带来性能问题。有什么方法可以更快地插入记录，因为我会为这个插入写一个程序？有没有其他我可以在过程中编写插入查询的地方？

Answer 1

在我的笔记本电脑上，我们可以轻松地扩展您的测试

SQL>
SQL> CREATE TABLE new_details_staging
  2  (
  3      e_id         NUMBER(10),
  4      e_name       VARCHAR2(30),
  5      portal_desc  VARCHAR2(50),
  6      risk_dec     VARCHAR2(50),
  7      CONSTRAINT pk_new_details_staging PRIMARY KEY (e_id)
  8  );

Table created.

SQL>
SQL> INSERT INTO new_details_staging VALUES (11, 'A', 'AA', 'High');

1 row created.

SQL> INSERT INTO new_details_staging  VALUES (22, 'B', 'BB', 'Low');

1 row created.

SQL>
SQL> insert into new_details_staging
  2  select e_id*500000+rownum, e_name, portal_desc, risk_dec
  3  from new_details_staging,
  4   ( select 1 from dual connect by level <= 400000 );

800000 rows created.

SQL>
SQL> CREATE TABLE lookup_ref
  2  (
  3      ref_id       NUMBER(10),
  4      ref_typ      VARCHAR2(30),
  5      ref_typ_desc VARCHAR2(20),
  6      CONSTRAINT pk_lookup_ref PRIMARY KEY (ref_id)
  7  );

Table created.

SQL>
SQL> INSERT INTO lookup_ref VALUES (181, 'portal', 'AA');

1 row created.

SQL> INSERT INTO lookup_ref VALUES (182, 'portal', 'BB');

1 row created.

SQL> INSERT INTO lookup_ref VALUES (183, 'risk', 'High');

1 row created.

SQL> INSERT INTO lookup_ref VALUES (184, 'risk', 'Low');

1 row created.

SQL>
SQL> CREATE TABLE new_details_main
  2  (
  3      e_id    NUMBER(10),
  4      e_name  VARCHAR2(30),
  5      portal  NUMBER(20),
  6      risk    NUMBER(20),
  7      CONSTRAINT pk_new_details_main PRIMARY KEY (e_id)
  8  );

Table created.

SQL>
SQL> set timing on
SQL> INSERT INTO new_details_main (e_id, e_name, portal,risk)
  2      SELECT
  3          n.e_id,
  4          n.e_name,
  5          (SELECT lr.ref_id
  6           FROM lookup_ref lr
  7           WHERE lr.ref_typ = 'portal'
  8             AND lr.ref_typ_desc = n.portal_desc),
  9          (SELECT lr.ref_id
 10           FROM lookup_ref lr
 11           WHERE lr.ref_typ = 'risk'
 12             AND lr.ref_typ_desc = n.risk_dec)
 13      FROM
 14          new_details_staging n;

800002 rows created.

Elapsed: 00:00:02.97
SQL>
SQL>

所以 800,000 行大约需要 3 秒。我想你会没事的:-)

如果查找始终为真并保留密钥，则转换为联接可能会带来一些好处，例如

SQL> set timing on
SQL> INSERT INTO new_details_main (e_id, e_name, portal,risk)
  2      SELECT
  3          n.e_id,
  4          n.e_name,
  5          lr.ref_id,
  6          lr1.ref_id
  7      FROM
  8          new_details_staging n,
  9          lookup_ref lr,
 10          lookup_ref lr1
 11  where lr.ref_typ = 'portal'
 12  AND lr.ref_typ_desc = n.portal_desc
 13  and lr1.ref_typ = 'risk'
 14  AND lr1.ref_typ_desc = n.risk_dec ;

800002 rows created.

Elapsed: 00:00:02.64

插入超过 40k+ 行时如何提高性能

How to increase performance when inserting more than 40k+ rows

sql

oracle

plsql