How to Perform a FAST SPLIT PARTITION Using ALTER TABLE? (Doc ID 1268714.1)
快速分割分区，就是如果最大的分区全部满足新split分区的条件，直接把最大的这个改名，再新加一个max分区出来。这样可以避免partition分区index的unsable，global index是否也是好的？
The Article: [ID 378138.1] states:
According to the documentation:
"Fast split partitioning takes advantage of those situations in which a split partition results in all rows being moved to a single partition. If all the rows map into a single partition and if the segment attributes of the old partition and the segment attributes of the partition inheriting all the rows match, then the database simply reuses the old segment and adds an empty segment for the other partition. Another benefit of this is that global indexes do not have to be invalidated and, in certain cases, local index partitions corresponding to the new partitions are also usable."
Thus, the new partitions should have the same storage configuration as the original partition.
This last statement has been the reason for the worked example below.
SOLUTION
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This has been tested on 10.2.0.5 and 11.2.
Logon to sqlplus
connect rk_mview/pwd
Create the partitioned table to work on.
drop TABLE test;
CREATE TABLE test
( GPS_GUID RAW(16) DEFAULT (sys_guid()) NOT NULL ENABLE,
DVC_ID NUMBER(12,0) NOT NULL ENABLE,
USR_ID NUMBER(12,0) NOT NULL ENABLE,
ENTRY_UTC TIMESTAMP (6) DEFAULT (SYS_EXTRACT_UTC(SYSTIMESTAMP)) NOT NULL ENABLE,
COVERAGE_STAT_ID NUMBER(12,0) NOT NULL ENABLE,
SPEED FLOAT(126) DEFAULT (0),
DIRECTION FLOAT(126) DEFAULT (0),
ESTIMATED_ACCURACY NUMBER(12,0),
UPDATE_UTC TIMESTAMP (6) DEFAULT (SYS_EXTRACT_UTC(SYSTIMESTAMP)) NOT NULL ENABLE,
LATITUDE FLOAT(126),
LONGITUDE FLOAT(126),
TS_GUID RAW(16),
CLUSTER_ID VARCHAR2(50),
GEOCODE_UTC TIMESTAMP (6),
STREET NVARCHAR2(100),
SUITE VARCHAR2(50),
CITY NVARCHAR2(100),
STATE_PROVINCE NVARCHAR2(100),
POSTAL_CODE NVARCHAR2(20),
COUNTRY NVARCHAR2(100),
CONSTRAINT PK_GPS PRIMARY KEY (GPS_GUID)
USING INDEX PCTFREE 5 INITRANS 10 MAXTRANS 255 COMPUTE STATISTICS
STORAGE(INITIAL 1M NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT)
TABLESPACE users ENABLE
) PCTFREE 30 PCTUSED 0 INITRANS 10 MAXTRANS 255
STORAGE(BUFFER_POOL DEFAULT)
TABLESPACE users
PARTITION BY RANGE (ENTRY_UTC)
(PARTITION GPS_DATA_2010_08_08 VALUES LESS THAN (TIMESTAMP'2010-08-08 00:00:00')
PCTFREE 5 PCTUSED 0 INITRANS 10 MAXTRANS 255
STORAGE(INITIAL 1M NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT)
TABLESPACE users NOCOMPRESS ,
PARTITION GPS_DATA_2010_08_15 VALUES LESS THAN (TIMESTAMP'2010-08-15 00:00:00')
PCTFREE 5 PCTUSED 0 INITRANS 10 MAXTRANS 255
STORAGE(INITIAL 1M NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT)
TABLESPACE users NOCOMPRESS ,
PARTITION GPS_DATA_MAX VALUES LESS THAN (MAXVALUE)
PCTFREE 5 PCTUSED 0 INITRANS 10 MAXTRANS 255
STORAGE(INITIAL 1M NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT)
TABLESPACE users NOCOMPRESS ) ENABLE ROW MOVEMENT;
insert into test values ('2',2,2,TIMESTAMP'2010-11-14 00:00:00',1,1,1,1,TIMESTAMP'2010-11-14 00:00:00',1,1,'1','1',TIMESTAMP'2010-11-14 00:00:00','1','1','1','1','1','1');
commit;
BEGIN
DBMS_STATS.gather_table_stats ('schema name',
'test',
partname => 'GPS_DATA_MAX',
granularity => 'PARTITION',
estimate_percent => 3,
DEGREE => 2 );
END;
/
In the above situation we can see that the row inserted has been added to the MAX partition, due to missing partitions. Therefore to provide further partitions to avoid the use of the MAX partition we will need to add a partition immediately before this MAX partition. We can use the SPLIT PARTITION syntax and this will actually perform a FAST SPLIT if all the data ends up in only one of the partitions.
Gather Statistics on the MAX partition to review the num_rows and to ensure a FAST SPLIT optimization occurs.
BEGIN
DBMS_STATS.gather_table_stats ('schema name',
'test',
partname => 'GPS_DATA_MAX',
granularity => 'PARTITION',
estimate_percent => 3,
DEGREE => 2 );
END;
/
Select Queries utilized to validate the split has occurred:
select FILE_ID,EXTENT_ID,BLOCK_ID from dba_extents where PARTITION_NAME='GPS_DATA_MAX';
select table_name,PARTITION_NAME, num_rows from dba_tab_partitions where table_name='test';
Now to run the actual split:
Note. Normally this will create 2 partitions and then move the data to each based on the partition boundaries. For a FAST SPLIT this will add a new partition and leave the data in the partition where the data fits.
ALTER TABLE test SPLIT PARTITION
GPS_DATA_MAX AT ((TIMESTAMP'2010-11-28 00:00:00 +0:00'))
INTO ( PARTITION GPS_DATA_2010_11_28
LOGGING
NOCOMPRESS
TABLESPACE users
PCTFREE 5
INITRANS 10
MAXTRANS 255
STORAGE (
INITIAL 1M
MINEXTENTS 1
MAXEXTENTS UNLIMITED
BUFFER_POOL DEFAULT
) ,
PARTITION GPS_DATA_MAX );
Proof the split has occurred:
BEFORE the split:
select FILE_ID,EXTENT_ID,BLOCK_ID,PARTITION_NAME from dba_extents where segment_NAME='test';
FILE_ID EXTENT_ID BLOCK_ID PARTITION_NAME
---------- ---------- ---------- ------------------------------
4 0 27657 GPS_DATA_2010_08_08
4 0 27785 GPS_DATA_2010_08_15
4 0 27913 GPS_DATA_MAX
select table_name,PARTITION_NAME, num_rows from dba_tab_partitions where table_name='test';
TABLE_NAME PARTITION_NAME NUM_ROWS
------------------------------ ------------------------------ ----------
GPS GPS_DATA_2010_08_08
GPS GPS_DATA_2010_08_15
GPS GPS_DATA_MAX 1
AFTER the split
select FILE_ID,EXTENT_ID,BLOCK_ID,PARTITION_NAME from dba_extents where segment_NAME='test';
FILE_ID EXTENT_ID BLOCK_ID PARTITION_NAME
---------- ---------- ---------- ------------------------------
4 0 27657 GPS_DATA_2010_08_08
4 0 27785 GPS_DATA_2010_08_15
4 0 27913 GPS_DATA_2010_11_28
4 0 26377 GPS_DATA_MAX
select table_name,PARTITION_NAME, num_rows from dba_tab_partitions where table_name='test';
TABLE_NAME PARTITION_NAME NUM_ROWS
------------------------------ ------------------------------ ----------
GPS GPS_DATA_2010_08_08
GPS GPS_DATA_2010_08_15
GPS GPS_DATA_MAX 0
GPS GPS_DATA_2010_11_28 1
So we can see from the above that the MAX partition has indeed become the new partition, and a new MAX has been added. So a fast split has occurred.
Confirmed FAST SPLIT Syntax
ALTER TABLE test SPLIT PARTITION
GPS_DATA_MAX AT ((TIMESTAMP'2010-11-20 00:00:00 +0:00'))
INTO ( PARTITION GPS_DATA_2010_11_20
LOGGING
NOCOMPRESS
TABLESPACE users
PCTFREE 5
INITRANS 10
MAXTRANS 255 -- This is the one that works. The pctfree, initrans and maxtrans outside the storage clause.
STORAGE
(INITIAL 1M NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
BUFFER_POOL DEFAULT),
PARTITION GPS_DATA_MAX );
