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在 oracle 中创建现有表的完整副本

更新时间:2023-02-03 16:11:13

你可以使用 DBMS_REDEFINITION 包,那个东西可以做整个表的副本,包括注释等.它还会碎片整理"新副本占用的空间比原始表少.

You can use DBMS_REDEFINITION package, that thing can do a copy of whole table including comments etc. It will also "defragment" the new copy to occupy less space than the original table.

更多信息请访问 https://docs.oracle.com/database/121/ARPLS/d_redefi.htm#ARPLS042

请求示例:

让我们创建一个测试模式、一个表并用一些数据填充它:

So let's create a test schema, a table and fill it with some data:

CREATE USER "TEST_SCHEMA" IDENTIFIED BY "TEST";
GRANT UNLIMITED TABLESPACE TO "TEST_SCHEMA";

CREATE TABLE "TEST_SCHEMA"."NAMES" ("ID" NUMBER, "NAME" VARCHAR2(25), PRIMARY KEY("ID"));

INSERT INTO "TEST_SCHEMA"."NAMES" VALUES (1, 'joe');
INSERT INTO "TEST_SCHEMA"."NAMES" VALUES (2, 'pete');
INSERT INTO "TEST_SCHEMA"."NAMES" VALUES (3, 'mark');

现在我们可以查看测试表的内容了:

Now we can check the content of the test table:

SELECT * FROM "TEST_SCHEMA"."NAMES";

让我们通过创建与源表完全一样的空表来开始复制过程(使用 WHERE 1=0,它不会接受任何数据).

Let's begin the copy process by creating empty table exactly as the source table looks like (using WHERE 1=0, which won't take any data).

CREATE TABLE "TEST_SCHEMA"."NAMES_COPY" AS SELECT * FROM "TEST_SCHEMA"."NAMES" "A1" WHERE 1=0;

在这里您可以设置并行化等,准备数据等.一切完成后,让我们开始重新定义过程:

Here you can setup paralellization etc, prepare data etc.. After everything is done, let's start the REDEFINITION process:

BEGIN
  DBMS_REDEFINITION.START_REDEF_TABLE('TEST_SCHEMA','NAMES','NAMES_COPY');
END;
/

复制内容时,我们需要复制每个依赖于表的对象(如触发器、索引等......)

When the contents is copied, we need to copy every object that is dependent on the table (like triggers, indexes etc....)

DECLARE
  num_errors PLS_INTEGER;
BEGIN
  DBMS_REDEFINITION.COPY_TABLE_DEPENDENTS ('TEST_SCHEMA',  'NAMES',    'NAMES_COPY',
    DBMS_REDEFINITION.CONS_ORIG_PARAMS, TRUE, TRUE, TRUE, TRUE, num_errors);
END;
/

我们可以使用这个查询检查在复制依赖项期间是否发生任何错误:

We can check if any errors occured during copying of dependencies with this query:

SELECT "OBJECT_NAME", "BASE_TABLE_NAME", "DDL_TXT" FROM DBA_REDEFINITION_ERRORS;

如果一切正常,我们就可以完成这个过程:

If everything is alright, we can finish the process:

BEGIN
  DBMS_REDEFINITION.FINISH_REDEF_TABLE ('TEST_SCHEMA', 'NAMES',    'NAMES_COPY');
END;
/

瞧,新桌子就像克隆羊多莉,里面装着所有东西:

And voila, the new table is like the cloned sheep Dolly with everything in it:

SELECT * FROM "TEST_SCHEMA"."NAMES_COPY";

现在要清理测试模式,运行这些:

Now to cleaup the test schema, run these:

DROP TABLE "TEST_SCHEMA"."NAMES";
DROP TABLE "TEST_SCHEMA"."NAMES_COPY";
DROP USER "TEST_SCHEMA" CASCADE;

希望对您有所帮助.