oracle 12cR2 过滤分区维护操作

Filtered Partition Maintenance Operations in Oracle Database 12c Release 2 (12.2)

Oracle Database 12c Release 2 (12.2) allows you to add a filter condition when you move, split or merge a partition, move a table or convert a non-partitioned table to a partitioned table. Only those rows matching the filter condition are included in the resulting object.

 Oracle 12cR2允许在移动、拆分和合并分区，移动表或者将普通表转换为分区表时增加过滤条件。只有满足过滤条件的行在结果对象中。

The filter condition is only allowed on heap tables, can only reference columns from the table and can be used in conjunction with online operations with some additional considerations.

过滤条件仅允许在堆组织表上使用，只能引用表中的列及结合一些在线操作的额外条件。

This article provides some simple examples using filter conditions with maintenance operations. The examples in this article are mostly based on partition management operations, but this functionality applies equally to subpartition maintenance operations.

    该文提供一些使用过滤条件的维护操作的简单示例。本文中的示例主要基于分区维护操作，但该功能同样使用于子分区的维护操作。

• Move a Table         移动表
• Convert a Non-Partitioned Table to a Partitioned Table      非分区表转换为分区表
• Move a Partition        移动分区
• Split a Partition          拆分分区
• Merge Partitions        合并分区

Related articles.

• All Partitioning Articles
• Partitioning Enhancements in Oracle Database 12c Release 2 (12.2)
• Online Move of Partitions and Sub-Partitions in Oracle 12c Release 1
• Online Conversion of a Non-Partitioned Table to a Partitioned Table in Oracle Database 12c Release 2 (12.2)
• Online Move of a Table in Oracle Database 12c Release 2 (12.2)

Move a Table

移动表

Create and populate a new test table.

创建和填充新测试表

DROP TABLE t1 PURGE;

CREATE TABLE t1 AS
SELECT level AS id,
       'Description for ' || level AS description
FROM   dual
CONNECT BY level <= 100;
COMMIT;

Check the contents of the table.

检查表内容

SELECT COUNT(*) AS total_rows,
       MIN(id) AS min_id,
       MAX(id) AS max_id
FROM   t1;

TOTAL_ROWS     MIN_ID     MAX_ID
---------- ---------- ----------
       100          1        100

SQL>

Move the table, filtering out rows with an ID value greater than 50.

移动表，过滤掉ID大于50的值：

ALTER TABLE t1 MOVE ONLINE
  INCLUDING ROWS WHERE id <= 50;

Check the contents of the table.

检查表内容

SELECT COUNT(*) AS total_rows,
       MIN(id) AS min_id,
       MAX(id) AS max_id
FROM   t1;

TOTAL_ROWS     MIN_ID     MAX_ID
---------- ---------- ----------
        50          1         50

SQL>

The rows with an ID value between 51 and 100 have been removed.

可见ID在51至100之间的值已经被移除。

Convert a Non-Partitioned Table to a Partitioned Table   

普通表转为分区表

Create and populate a new test table.

DROP TABLE t1 PURGE;

CREATE TABLE t1 AS
SELECT level AS id,
       'Description for ' || level AS description
FROM   dual
CONNECT BY level <= 100;
COMMIT;

Check the contents of the table.

SELECT COUNT(*) AS total_rows,
       MIN(id) AS min_id,
       MAX(id) AS max_id
FROM   t1;

TOTAL_ROWS     MIN_ID     MAX_ID
---------- ---------- ----------
       100          1        100

SQL>

Convert the table to a partitioned, filtering out rows with an ID value greater than 50.

转为分区表，过滤掉ID值大于50的值.

ALTER TABLE t1 MODIFY
  PARTITION BY RANGE (id) (
    PARTITION t1_le_50 VALUES LESS THAN (51),
    PARTITION t1_le_101 VALUES LESS THAN (101)
  )
  INCLUDING ROWS WHERE id <= 50;

Check the contents of the partitions.

EXEC DBMS_STATS.gather_table_stats(USER, 'T1');

COLUMN table_name FORMAT A20
COLUMN partition_name FORMAT A20
COLUMN high_value FORMAT A20

SELECT table_name, partition_name, high_value, num_rows
FROM   user_tab_partitions
WHERE  table_name = 'T1'
ORDER BY 1,2;

TABLE_NAME           PARTITION_NAME       HIGH_VALUE             NUM_ROWS
-------------------- -------------------- -------------------- ----------
T1                   T1_LE_101            101                           0
T1                   T1_LE_50             51                           50

SQL>


SELECT COUNT(*) AS total_rows,
       MIN(id) AS min_id,
       MAX(id) AS max_id
FROM   t1;

TOTAL_ROWS     MIN_ID     MAX_ID
---------- ---------- ----------
        50          1         50

SQL>

The rows with an ID value between 51 and 100 have been removed.

Move a Partition  

移动分区

Create and populate a new test partitioned table.

DROP TABLE t1 PURGE;

CREATE TABLE t1 (
  id            NUMBER,
  description   VARCHAR2(50)
)
PARTITION BY RANGE (id)
(
  PARTITION t1_le_50 VALUES LESS THAN (51),
  PARTITION t1_le_101 VALUES LESS THAN (101)
);

INSERT INTO t1
SELECT level AS id,
       'Description for ' || level AS description
FROM   dual
CONNECT BY level <= 100;
COMMIT;

Check the contents of the partitions.

EXEC DBMS_STATS.gather_table_stats(USER, 'T1');

COLUMN table_name FORMAT A20
COLUMN partition_name FORMAT A20
COLUMN high_value FORMAT A20

SELECT table_name, partition_name, high_value, num_rows
FROM   user_tab_partitions
WHERE  table_name = 'T1'
ORDER BY 1,2;

TABLE_NAME           PARTITION_NAME       HIGH_VALUE             NUM_ROWS
-------------------- -------------------- -------------------- ----------
T1                   T1_LE_101            101                          50
T1                   T1_LE_50             51                           50

SQL>


SELECT COUNT(*) AS total_rows,
       MIN(id) AS min_id,
       MAX(id) AS max_id
FROM   t1;

TOTAL_ROWS     MIN_ID     MAX_ID
---------- ---------- ----------
       100          1        100

SQL>

Move a partition, filtering out rows with an ID value greater than 50.

移动分区，过滤掉ID大于50的值：

ALTER TABLE t1 MOVE PARTITION t1_le_101 ONLINE TABLESPACE users
  INCLUDING ROWS WHERE id <= 50;

Check the contents of the partitions.

EXEC DBMS_STATS.gather_table_stats(USER, 'T1');

COLUMN table_name FORMAT A20
COLUMN partition_name FORMAT A20
COLUMN high_value FORMAT A20

SELECT table_name, partition_name, high_value, num_rows
FROM   user_tab_partitions
WHERE  table_name = 'T1'
ORDER BY 1,2;

TABLE_NAME           PARTITION_NAME       HIGH_VALUE             NUM_ROWS
-------------------- -------------------- -------------------- ----------
T1                   T1_LE_101            101                           0
T1                   T1_LE_50             51                           50

SQL>


SELECT COUNT(*) AS total_rows,
       MIN(id) AS min_id,
       MAX(id) AS max_id
FROM   t1;

TOTAL_ROWS     MIN_ID     MAX_ID
---------- ---------- ----------
        50          1         50

SQL>

The rows with an ID value between 51 and 100 have been removed.

Split a Partition  

拆分分区 

Create and populate a new test partitioned table.

DROP TABLE t1 PURGE;

CREATE TABLE t1 (
  id            NUMBER,
  description   VARCHAR2(50)
)
PARTITION BY RANGE (id)
(
  PARTITION t1_le_101 VALUES LESS THAN (101)
);

INSERT INTO t1
SELECT level AS id,
       'Description for ' || level AS description
FROM   dual
CONNECT BY level <= 100;
COMMIT;

Check the contents of the partition.

EXEC DBMS_STATS.gather_table_stats(USER, 'T1');

COLUMN table_name FORMAT A20
COLUMN partition_name FORMAT A20
COLUMN high_value FORMAT A20

SELECT table_name, partition_name, high_value, num_rows
FROM   user_tab_partitions
WHERE  table_name = 'T1'
ORDER BY 1,2;

TABLE_NAME           PARTITION_NAME       HIGH_VALUE             NUM_ROWS
-------------------- -------------------- -------------------- ----------
T1                   T1_LE_101            101                         100

SQL>


SELECT COUNT(*) AS total_rows,
       MIN(id) AS min_id,
       MAX(id) AS max_id
FROM   t1;

TOTAL_ROWS     MIN_ID     MAX_ID
---------- ---------- ----------
       100          1        100

SQL>

Split the partition, filtering out rows with an ID value greater than 50.

拆分分区，过滤掉ID值大于50的值：

ALTER TABLE t1
  SPLIT PARTITION t1_le_101 AT (51)
  INTO (PARTITION t1_le_51,
        PARTITION t1_le_101)
  INCLUDING ROWS WHERE id <= 50
  ONLINE;

Check the contents of the partitions.

EXEC DBMS_STATS.gather_table_stats(USER, 'T1');

COLUMN table_name FORMAT A20
COLUMN partition_name FORMAT A20
COLUMN high_value FORMAT A20

SELECT table_name, partition_name, high_value, num_rows
FROM   user_tab_partitions
WHERE  table_name = 'T1'
ORDER BY 1,2;

TABLE_NAME           PARTITION_NAME       HIGH_VALUE             NUM_ROWS
-------------------- -------------------- -------------------- ----------
T1                   T1_LE_101            101                           0
T1                   T1_LE_51             51                           50

SQL>


SELECT COUNT(*) AS total_rows,
       MIN(id) AS min_id,
       MAX(id) AS max_id
FROM   t1;

TOTAL_ROWS     MIN_ID     MAX_ID
---------- ---------- ----------
        50          1         50

SQL>

The rows with an ID value between 51 and 100 have been removed.

Merge Partitions  

合并分区

Create and populate a new test partitioned table.

DROP TABLE t1 PURGE;

CREATE TABLE t1 (
  id            NUMBER,
  description   VARCHAR2(50)
)
PARTITION BY RANGE (id)
(
  PARTITION t1_le_51 VALUES LESS THAN (51),
  PARTITION t1_le_101 VALUES LESS THAN (101)
);

INSERT INTO t1
SELECT level AS id,
       'Description for ' || level AS description
FROM   dual
CONNECT BY level <= 100;
COMMIT;

Check the contents of the partitions.

EXEC DBMS_STATS.gather_table_stats(USER, 'T1');

COLUMN table_name FORMAT A20
COLUMN partition_name FORMAT A20
COLUMN high_value FORMAT A20

SELECT table_name, partition_name, high_value, num_rows
FROM   user_tab_partitions
WHERE  table_name = 'T1'
ORDER BY 1,2;

TABLE_NAME           PARTITION_NAME       HIGH_VALUE             NUM_ROWS
-------------------- -------------------- -------------------- ----------
T1                   T1_LE_101            101                          50
T1                   T1_LE_51             51                           50

SQL>


SELECT COUNT(*) AS total_rows,
       MIN(id) AS min_id,
       MAX(id) AS max_id
FROM   t1;

TOTAL_ROWS     MIN_ID     MAX_ID
---------- ---------- ----------
       100          1        100

SQL>

Merge the partitions, filtering out rows with an ID value greater than 50.

合并分区，过滤掉ID值大于50的值：

ALTER TABLE t1
  MERGE PARTITIONS t1_le_51, t1_le_101
  INTO PARTITION t1_le_101
  INCLUDING ROWS WHERE id <= 50;

Check the contents of the partitions.

EXEC DBMS_STATS.gather_table_stats(USER, 'T1');

COLUMN table_name FORMAT A20
COLUMN partition_name FORMAT A20
COLUMN high_value FORMAT A20

SELECT table_name, partition_name, high_value, num_rows
FROM   user_tab_partitions
WHERE  table_name = 'T1'
ORDER BY 1,2;

TABLE_NAME           PARTITION_NAME       HIGH_VALUE             NUM_ROWS
-------------------- -------------------- -------------------- ----------
T1                   T1_LE_101            101                          50

SQL>


SELECT COUNT(*) AS total_rows,
       MIN(id) AS min_id,
       MAX(id) AS max_id
FROM   t1;

TOTAL_ROWS     MIN_ID     MAX_ID
---------- ---------- ----------
        50          1         50

SQL>

The rows with an ID value between 51 and 100 have been removed.