Monday, 24 October 2022

Table Partition and Maintenance in oracle

 There is different type of Table partition


  1. Range Partitioning
  2. Hash Partitioning
  3. List Partitioning
  4. Composite Range-Hash Partitioning
  5. Composite Range-List Partitioning


Create Partitioned Tables Of Different Partition Types

1.Range Partitioning

The following statement creates a table sales_range that is range partitioned on the sales_date field:


CREATE TABLE sales_range

(salesman_id NUMBER(5),

salesman_name VARCHAR2(30),

sales_amount NUMBER(10),

sales_date DATE)

PARTITION BY RANGE(sales_date)

(PARTITION sales_jan2000 VALUES LESS THAN(TO_DATE('02/01/2000','DD/MM/YYYY')),

PARTITION sales_feb2000 VALUES LESS THAN(TO_DATE('03/01/2000','DD/MM/YYYY')),

PARTITION sales_mar2000 VALUES LESS THAN(TO_DATE('04/01/2000','DD/MM/YYYY')),

PARTITION sales_apr2000 VALUES LESS THAN(TO_DATE('05/01/2000','DD/MM/YYYY')));


2.Hash Partitioning

The following statement creates a table sales_hash, which is hash partitioned on the salesman_id field:


CREATE TABLE sales_hash

(salesman_id NUMBER(5),

salesman_name VARCHAR2(30),

sales_amount NUMBER(10),

week_no NUMBER(2))

PARTITION BY HASH(salesman_id)

PARTITIONS 4;

3.List Partitioning

The following example creates a list partitioned table grouping states according to their sales regions:


CREATE TABLE sales_list

(salesman_id NUMBER(5),

salesman_name VARCHAR2(30),

sales_state VARCHAR2(20),

sales_amount NUMBER(10),

sales_date DATE)

PARTITION BY LIST(sales_state)

(PARTITION sales_west VALUES('California', 'Hawaii'),

PARTITION sales_east VALUES ('New York', 'Virginia', 'Florida'),

PARTITION sales_central VALUES('Texas', 'Illinois'),

PARTITION sales_other VALUES(DEFAULT));


4)Composite Range-Hash Partitioning

The following example partitions the table sales_range_hash by range on the column s_saledate to create four partitions that order data by time. Then, within each range partition, the data is further subdivided into 16 subpartitions by hash on the column s_productid:


CREATE TABLE sales_range_hash(

s_productid NUMBER,

s_saledate DATE,

s_custid NUMBER,

s_totalprice NUMBER)

PARTITION BY RANGE (s_saledate)

SUBPARTITION BY HASH (s_productid) SUBPARTITIONS 8

(PARTITION sal99q1 VALUES LESS THAN (TO_DATE('01-APR-1999', 'DD-MON-YYYY')),

PARTITION sal99q2 VALUES LESS THAN (TO_DATE('01-JUL-1999', 'DD-MON-YYYY')),

PARTITION sal99q3 VALUES LESS THAN (TO_DATE('01-OCT-1999', 'DD-MON-YYYY')),

PARTITION sal99q4 VALUES LESS THAN (TO_DATE('01-JAN-2000', 'DD-MON-YYYY')));


5.Composite Range-List Partitioning

This statement creates a table halfyeraly_regional_sales that is range partitioned on the txn_date field and list subpartitioned on state.


CREATE TABLE quarterly_regional_sales

(deptno NUMBER, item_no VARCHAR2(20),

txn_date DATE, txn_amount NUMBER, state VARCHAR2(2))

PARTITION BY RANGE (txn_date)

SUBPARTITION BY LIST (state)

(

PARTITION q1_1999 VALUES LESS THAN(TO_DATE('1-APR-1999','DD-MON-YYYY'))

(SUBPARTITION q1_1999_northwest VALUES ('OR', 'WA'),

SUBPARTITION q1_1999_southwest VALUES ('AZ', 'UT'),

SUBPARTITION q1_1999_northeast VALUES ('NY', 'VM', 'NJ'),

SUBPARTITION q1_1999_southeast VALUES ('FL', 'GA'),

SUBPARTITION q1_1999_northcentral VALUES ('SD', 'WI'),

SUBPARTITION q1_1999_southcentral VALUES ('NM', 'TX')),


PARTITION q2_1999 VALUES LESS THAN(TO_DATE('1-JUL-1999','DD-MON-YYYY'))


(SUBPARTITION q2_1999_northwest VALUES ('OR', 'WA'),

SUBPARTITION q2_1999_southwest VALUES ('AZ', 'UT'),

SUBPARTITION q2_1999_northeast VALUES ('NY', 'VM', 'NJ'),

SUBPARTITION q2_1999_southeast VALUES ('FL', 'GA'),

SUBPARTITION q2_1999_northcentral VALUES ('SD', 'WI'),

SUBPARTITION q2_1999_southcentral VALUES ('NM', 'TX')),


PARTITION q3_1999 VALUES LESS THAN (TO_DATE('1-OCT-1999','DD-MON-YYYY'))


(SUBPARTITION q3_1999_northwest VALUES ('OR', 'WA'),

SUBPARTITION q3_1999_southwest VALUES ('AZ', 'UT'),

SUBPARTITION q3_1999_northeast VALUES ('NY', 'VM', 'NJ'),

SUBPARTITION q3_1999_southeast VALUES ('FL', 'GA'),

SUBPARTITION q3_1999_northcentral VALUES ('SD', 'WI'),

SUBPARTITION q3_1999_southcentral VALUES ('NM', 'TX')),


PARTITION q4_1999 VALUES LESS THAN (TO_DATE('1-JAN-2000','DD-MON-YYYY'))


(SUBPARTITION q4_1999_northwest VALUES('OR', 'WA'),

SUBPARTITION q4_1999_southwest VALUES('AZ', 'UT'),

SUBPARTITION q4_1999_northeast VALUES('NY', 'VM', 'NJ'),

SUBPARTITION q4_1999_southeast VALUES('FL', 'GA'),

SUBPARTITION q4_1999_northcentral VALUES ('SD', 'WI'),

SUBPARTITION q4_1999_southcentral VALUES ('NM', 'TX')));


Table Maintenance

ADDING PARTITION

ALTER TABLE ... ADD PARTITION statement is used to add a new partition to the "high" end (the point after the last existing partition). To add a partition at the beginning or in the middle of a table,  SPLIT PARTITION clause can be used.

Prerequisites:

The table must be in your own schema, or you must have ALTER object privilege on the table, or you must have ALTER ANY TABLE system privilege.

You must also have space quota in the tablespace in which space is to be acquired in order to use the add_table_partition, modify_table_partition, move_table_partition, and split_table_partition clauses.


1)Adding a Partition to a Range-Partitioned Table:

For example consider table PRICE_VALUE.It containing data for 2007 and 2008.


SQL> CREATE TABLE <table name>(

current_dat date,

cost number(23))

partition by range(current_dat)

(PARTITION PRICES_2007

VALUES LESS THAN (TO_DATE('01-JAN-2008', 'DD-MON-YYYY')),

PARTITION PRICES_2008

VALUES LESS THAN (TO_DATE('01-JAN-2009', 'DD-MON-YYYY')));

SQL> select table_name,partition_name from user_tab_partitions where table_name='<table name>';

TABLE_NAME PARTITION_NAME

------------------------------ ------------------------------

PRICE_VALUE PRICES_2007

PRICE_VALUE PRICES_2008

A new partition for year 2009 can be added as:

SQL> Alter table <table name> add partition PRICES_2009 values less than(TO_DATE('01-JAN-2010', 'DD-MON-YYYY'));

SQL> select table_name,partition_name from user_tab_partitions where table_name='PRICE_VALUE';

TABLE_NAME PARTITION_NAME

------------------------------ ------------------------------

PRICE_VALUE PRICES_2007

PRICE_VALUE PRICES_2008

PRICE_VALUE PRICES_2009


NOTE: Local and global indexes associated with the range-partitioned table remain usable.

2)Adding a Partition to a Hash-Partitioned Table:

Consider the following table:

SQL>CREATE TABLE PRODUCT

(product_id NUMBER,

name VARCHAR2 (60))

PARTITION BY HASH (product_id)

PARTITIONS 4;


SQL>select table_name,partition_name from user_tab_partitions where table_name='PRODUCT';

TABLE_NAME PARTITION_NAME

------------------------------ ------------------------------

PRODUCT SYS_P23

PRODUCT SYS_P24

PRODUCT SYS_P25

PRODUCT SYS_P26


A new partition can be added as:


SQL>alter table product add partition;

SQL>select table_name,partition_name from user_tab_partitions where table_name='PRODUCT';


TABLE_NAME PARTITION_NAME

------------------------------ ------------------------------

PRODUCT SYS_P23

PRODUCT SYS_P24

PRODUCT SYS_P25

PRODUCT SYS_P26

PRODUCT SYS_P27 


Choosing the above method adds a new hash partition whose partition name is system generated, and which is placed in the table default tablespace.

To adds a new hash partition, explicitly named p_named and tablespace gear5,use the following method:


SQL>alter table product ADD PARTITION p_named TABLESPACE gear5;

SQL> select table_name,partition_name,tablespace_name from user_tab_partitions where table_name='PRODUCT';


TABLE_NAME PARTITION_NAME TABLESPACE_NAME

------------------------------ ------------------------------

PRODUCT P_NAMED GEAR5

PRODUCT SYS_P21 SYSTEM

PRODUCT SYS_P22 SYSTEM

PRODUCT SYS_P23 SYSTEM

PRODUCT SYS_P24 SYSTEM

PRODUCT SYS_P25 SYSTEM


NOTE:

For Regular(Heap) tables----->

Unless you specify UPDATE INDEXES as part of the ALTER TABLE statement:

* The local indexes for the new partition, and for the existing partition from which rows were redistributed, are marked UNUSABLE and must be rebuilt.

* All global indexes, or all partitions of partitioned global indexes, are marked UNUSABLE and must be rebuilt.


For Index-organized tables-------->


* For local indexes, the behavior is the same as for heap tables.

* All global indexes remain usable.


3)Adding a Partition to a List-Partitioned Table:

Consider the following table:


SQL>CREATE TABLE <table name>

(deptno number,

deptname varchar2(20),

quarterly_sales number(10, 2),

state varchar2(2))

PARTITION BY LIST (state)

(PARTITION northwest VALUES ('OR', 'WA'),

PARTITION southwest VALUES ('AZ', 'UT', 'NM'),

PARTITION northeast VALUES ('NY', 'VM', 'NJ'),

PARTITION southeast VALUES ('FL', 'GA'),

PARTITION northcentral VALUES ('SD', 'WI'));


SQL> select table_name,partition_name from user_tab_partitions where table_name='<table name>';


TABLE_NAME PARTITION_NAME

------------------------------ ------------------------------

SALES_BY_REGION NORTHCENTRAL

SALES_BY_REGION NORTHEAST

SALES_BY_REGION NORTHWEST

SALES_BY_REGION SOUTHEAST

SALES_BY_REGION SOUTHWEST


To add a new partition:


SQL> alter table <table name>add PARTITION southcentral VALUES ('OK', 'TX');

SQL> select table_name,partition_name from user_tab_partitions where table_name='<table name>';


TABLE_NAME PARTITION_NAME

------------------------------ ------------------------------

SALES_BY_REGION NORTHCENTRAL

SALES_BY_REGION NORTHEAST

SALES_BY_REGION NORTHWEST

SALES_BY_REGION SOUTHCENTRAL

SALES_BY_REGION SOUTHEAST

SALES_BY_REGION SOUTHWEST


NOTE:

Any value in the set of literal values that describe the partition being added must not exist in any of the other partitions of the table.

You cannot add a partition to a list-partitioned table that has a default partition, but you can split the default partition. By doing so, you effectively create a new partition defined by the values that you specify, and a second partition that remains the default partition.

Local and global indexes associated with the list-partitioned table remain usable.


4)Adding Partitions to a Range-Hash Composite-Partitioned Table:

Partitions can be added at both the range partition level and the hash subpartition level.

SQL> CREATE TABLE sales_product

(prod_id number,

prod_name varchar2(20),

price number)

PARTITION BY RANGE(prod_id) SUBPARTITION BY HASH(prod_name)

SUBPARTITION TEMPLATE(

SUBPARTITION sp1)

(PARTITION sale_pa1 VALUES LESS THAN (1000),

PARTITION sale_pa2 VALUES LESS THAN (2000));


SQL> select table_name,partition_name,subpartition_name from user_tab_subpartitions where table_name='SALES_PRODUCT';


TABLE_NAME PARTITION_NAME

------------------------------ ------------------------------

SUBPARTITION_NAME

------------------------------

SALES_PRODUCT SALE_PA1

SALE_PA1_SP1

SALES_PRODUCT SALE_PA2

SALE_PA2_SP1


SQL> select table_name,partition_name,subpartition_name from user_tab_subpartitions where table_name='SALES_PRODUCT';


TABLE_NAME PARTITION_NAME

------------------------------ ------------------------------

SUBPARTITION_NAME

------------------------------

SALES_PRODUCT SALE_PA1

SALE_PA1_SP1

SALES_PRODUCT SALE_PA2

SALE_PA2_SP1

SALES_PRODUCT SAL_PA3

SAL_PA3_SP1


---- Adding a Subpartition to a Range-Hash Partitioned Table:


SQL>ALTER TABLE SALES_PRODUCT MODIFY PARTITION SALE_PA1

ADD SUBPARTITION SAL_PA4;

SQL> select table_name,partition_name,subpartition_name from user_tab_subpartitions where table_name='SALES_PRODUCT';


TABLE_NAME PARTITION_NAME

------------------------------ ------------------------------

SUBPARTITION_NAME

------------------------------

SALES_PRODUCT SALE_PA1

SALE_PA1_SP1

SALES_PRODUCT SALE_PA1

SAL_PA4

SALES_PRODUCT SALE_PA2

SALE_PA2_SP1


TABLE_NAME PARTITION_NAME

------------------------------ ------------------------------

SUBPARTITION_NAME

------------------------------

SALES_PRODUCT SAL_PA3

SAL_PA3_SP1


NOTE:Index subpartitions corresponding to the added and rehashed subpartitions must be rebuilt unless you specify UPDATE INDEXES


5)Adding a Partition to a Range-List Partitioned Table:

Partitions can be added at both the range partition level and the list subpartition level.


SQL> CREATE TABLE sales_product

(prod_id number,

prod_name varchar2(20),

price number)

PARTITION BY RANGE(prod_id) SUBPARTITION BY LIST (prod_name)

SUBPARTITION TEMPLATE(

SUBPARTITION Prod1 VALUES('SK', 'LM', 'TG'),

SUBPARTITION prod2 VALUES('CF', 'AR', 'HI'))

(PARTITION sale_pa1 VALUES LESS THAN (1000));


SQL> select table_name,partition_name,subpartition_name from user_tab_subpartitions where table_name='SALES_PRODUCT';


TABLE_NAME PARTITION_NAME

------------------------------ ------------------------------

SUBPARTITION_NAME

------------------------------

SALES_PRODUCT SALE_PA1

SALE_PA1_PROD1

SALES_PRODUCT SALE_PA1

SALE_PA1_PROD2


Following statement statements adds a new partition to the SALES_PRODUCT table:


SQL> ALTER TABLE sales_product

ADD PARTITION sal_pa2 VALUES LESS THAN (2000)

(SUBPARTITION prod3 VALUES('IL', 'OK', 'FG'));


Some new physical attributes can be  specified for this new partition while table-level defaults are inherited for those that are not specified as:


SQL> ALTER TABLE sales_product

ADD PARTITION sal_pa2 VALUES LESS THAN (2000)

STORAGE (INITIAL 20K NEXT 20K) TABLESPACE ts3 NOLOGGING

(SUBPARTITION prod3 VALUES('IL', 'OK', 'FG'));


SQL> select table_name,partition_name,subpartition_name from user_tab_subpartitions where table_name='SALES_PRODUCT';


TABLE_NAME PARTITION_NAME

------------------------------ ------------------------------

SUBPARTITION_NAME

------------------------------

SALES_PRODUCT SALE_PA1

SALE_PA1_PROD1


SALES_PRODUCT SALE_PA1

SALE_PA1_PROD2


SALES_PRODUCT SAL_PA2

PROD3


----Adding a Subpartition to a Range-List Partitioned Table:

MODIFY PARTITION ... ADD SUBPARTITION clause of the ALTER TABLE statement can be used to add a list subpartition.


SQL>ALTER TABLE sales_product

MODIFY PARTITION sale_pa1

ADD SUBPARTITION prod_south

VALUES ('MS','AL');


The new subpartition can be created in tablespace ts2 as well

SQL>ALTER TABLE sales_product

MODIFY PARTITION sale_pa1

ADD SUBPARTITION prod_south

VALUES ('MS','AL') tablespace ts2;


SQL> select table_name,partition_name,subpartition_name from user_tab_subpartitions where table_name='SALES_PRODUCT';


TABLE_NAME PARTITION_NAME

------------------------------ ------------------------------

SUBPARTITION_NAME

------------------------------

SALES_PRODUCT SALE_PA1

PROD_SOUTH

SALES_PRODUCT SALE_PA1

SALE_PA1_PROD1

SALES_PRODUCT SALE_PA1

SALE_PA1_PROD2


TABLE_NAME PARTITION_NAME

------------------------------ ------------------------------

SUBPARTITION_NAME

------------------------------

SALES_PRODUCT SAL_PA2

PROD3


Real-time Example

To Add New Partition


select PARTITION_NAME,PARTITION_POSITION,HIGH_VALUE from dba_tab_partitions where TABLE_OWNER='EASYOWNER' and TABLE_NAME='EASYINVOICE' order by PARTITION_POSITION ;


PARTITION_NAME                 PARTITION_POSITION HIGH_VALUE

------------------------------ ------------------ --------------------------------------------------------------------------------

EASYINVOICE_PARTITION1                         1 TO_DATE(' 2015-12-31 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA

EASYINVOICE_PARTITION2                         2 TO_DATE(' 2016-06-30 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA

EASYINVOICE_PARTITION3                         3 TO_DATE(' 2016-12-31 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA

EASYINVOICE_PARTITION4                         4 TO_DATE(' 2017-06-30 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA

EASYINVOICE_PARTITION5                         5 TO_DATE(' 2017-12-31 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA


SQL> alter table EASYOWNER.EASYINVOICE add partition EASYINVOICE_PARTITION6 values less than (to_date('30062018','ddmmyyyy'));


set long 5000

select dbms_metadata.get_ddl('TABLE','EASYINVOICE','EASYOWNER') from dual;


SQL> select INDEX_NAME,PARTITIONED from  dba_indexes where TABLE_NAME='EASYINVOICE' and  TABLE_OWNER='EASYOWNER';


INDEX_NAME                     PAR

------------------------------ ---

EASYINVOICE_PART_INDEX1       NO


SQL> select PARTITION_NAME,PARTITION_POSITION,HIGH_VALUE from dba_tab_partitions where TABLE_OWNER='EASYOWNER' and TABLE_NAME='EASYINVOICE' order by PARTITION_POSITION ;


SQL> ALTER TABLE EASYOWNER.EASYINVOICE ADD PARTITION P4 VALUES LESS THAN (20181231) ;


Table altered.

SQL> select INDEX_NAME,STATUS,PARTITIONED from  dba_indexes where TABLE_NAME='EASYINVOICE' and  TABLE_OWNER='EASYOWNER';

INDEX_NAME                     STATUS   PAR

------------------------------ -------- ---

EASYINVOICE_PART_INDEX1       VALID    NO

Solution:

This error is because, the value which we are trying to insert is not satisfying the partition key range criteria.

Lets check the partition details.

SQL> select partition_name,high_value from dba_tab_partitions where table_name='EASYINVOICE';


PARTITION_NAME HIGH_VALUE

-------------- --------------------------------------------------------------------------------

P3             TO_DATE(' 2016-03-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA

P2             TO_DATE(' 2016-02-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA

P1             TO_DATE(' 2016-01-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIA


Partitioning Indexes

There are two basic types of partitioned index.


Local - All index entries in a single partition will correspond to a single table partition (equipartitioned). They are created with the LOCAL keyword and support partition independance. Equipartioning allows oracle to be more efficient whilst devising query plans.

Global - Index in a single partition may correspond to multiple table partitions. They are created with the GLOBAL keyword and do not support partition independance. Global indexes can only be range partitioned and may be partitioned in such a fashion that they look equipartitioned, but Oracle will not take advantage of this structure.

Both types of indexes can be subdivided further.


Prefixed - The partition key is the leftmost column(s) of the index. Probing this type of index is less costly. If a query specifies the partition key in the where clause partition pruning is possible, that is, not all partitions will be searched.

Non-Prefixed - Does not support partition pruning, but is effective in accessing data that spans multiple partitions. Often used for indexing a column that is not the tables partition key, when you would like the index to be partitioned on the same key as the underlying table.

Local Prefixed Indexes

Assuming the INVOICES table is range partitioned on INVOICE_DATE, the followning are examples of local prefixed indexes.


CREATE INDEX invoices_idx ON invoices (invoice_date) LOCAL;


CREATE INDEX invoices_idx ON invoices (invoice_date) LOCAL

 (PARTITION invoices_q1 TABLESPACE users,

  PARTITION invoices_q2 TABLESPACE users,

  PARTITION invoices_q3 TABLESPACE users,

  PARTITION invoices_q4 TABLESPACE users);

Oracle will generate the partition names and build the partitions in the default tablespace using the default size unless told otherwise.


Local Non-Prefixed Indexes

Assuming the INVOICES table is range partitioned on INVOICE_DATE, the following example is of a local non-prefixed index. The indexed column does not match the partition key.


CREATE INDEX invoices_idx ON invoices (invoice_no) LOCAL

 (PARTITION invoices_q1 TABLESPACE users,

  PARTITION invoices_q2 TABLESPACE users,

  PARTITION invoices_q3 TABLESPACE users,

  PARTITION invoices_q4 TABLESPACE users);

Global Prefixed Indexes

Assuming the INVOICES table is range partitioned on INVOICE_DATE, the followning examples is of a global prefixed index.


CREATE INDEX invoices_idx ON invoices (invoice_date)

GLOBAL PARTITION BY RANGE (invoice_date)

 (PARTITION invoices_q1 VALUES LESS THAN (TO_DATE('01/04/2001', 'DD/MM/YYYY')) TABLESPACE users,

  PARTITION invoices_q2 VALUES LESS THAN (TO_DATE('01/07/2001', 'DD/MM/YYYY')) TABLESPACE users,

  PARTITION invoices_q3 VALUES LESS THAN (TO_DATE('01/09/2001', 'DD/MM/YYYY')) TABLESPACE users,

  PARTITION invoices_q4 VALUES LESS THAN (MAXVALUE) TABLESPACE users);

Note that the partition range values must be specified. The GLOBAL keyword means that Oracle can not assume the partition key is the same as the underlying table.


Global Non-Prefixed Indexes

Oracle does not support Global Non Prefixed indexes.


Partitioning Existing Tables

The ALTER TABLE ... EXCHANGE PARTITION ... syntax can be used to partition an existing table, as shown by the following example. First we must create a non-partitioned table to act as our starting point.


CREATE TABLE my_table (

  id           NUMBER,

  description  VARCHAR2(50)

);


INSERT INTO my_table (id, description) VALUES (1, 'One');

INSERT INTO my_table (id, description) VALUES (2, 'Two');

INSERT INTO my_table (id, description) VALUES (3, 'Three');

INSERT INTO my_table (id, description) VALUES (4, 'Four');

COMMIT;

Next we create a new partitioned table with a single partition to act as our destination table.


CREATE TABLE my_table_2 (

  id           NUMBER,

  description  VARCHAR2(50)

)

PARTITION BY RANGE (id)

(PARTITION my_table_part VALUES LESS THAN (MAXVALUE));

Next we switch the original table segment with the partition segment.


ALTER TABLE my_table_2

  EXCHANGE PARTITION my_table_part

  WITH TABLE my_table

  WITHOUT VALIDATION;

We can now drop the original table and rename the partitioned table.


DROP TABLE my_table;

RENAME my_table_2 TO my_table;

Finally we can split the partitioned table into multiple partitions as required and gather new statistics.


ALTER TABLE my_table SPLIT PARTITION my_table_part AT (3)

INTO (PARTITION my_table_part_1,

      PARTITION my_table_part_2);

      

EXEC DBMS_STATS.gather_table_stats(USER, 'MY_TABLE', cascade => TRUE);

The following query shows that the partitioning process is complete.


COLUMN high_value FORMAT A20

SELECT table_name,

       partition_name,

       high_value,

       num_rows

FROM   user_tab_partitions

ORDER BY table_name, partition_name;


TABLE_NAME                     PARTITION_NAME                 HIGH_VALUE             NUM_ROWS

------------------------------ ------------------------------ -------------------- ----------

MY_TABLE                       MY_TABLE_PART_1                3                             2

MY_TABLE                       MY_TABLE_PART_2                MAXVALUE                      2


2 rows selected.



To Drop partition from Table, please follow below steps


1. Take the export backup of EASY table with permanent retention into tape.

2. Take the size of the table

SQL> select segment_name,sum(bytes)/1024/1024/1024 from dba_segments where segment_name='EASYINVOICE' group by segment_name;


SEGMENT_NAME    SUM(BYTES)/1024/1024/1024

--------------- -------------------------

EASYINVOICE                73.3447266

SQL>

3.Take out the partittion details using below query

select PARTITION_NAME,PARTITION_POSITION,HIGH_VALUE from dba_tab_partitions where TABLE_NAME='EASYINVOICE'

Current Production partition details:--

SQL> col PARTITION_NAME for a30

SQL> select PARTITION_NAME,PARTITION_POSITION,HIGH_VALUE from dba_tab_partitions where TABLE_NAME='EASYINVOICE';


PARTITION_NAME                 PARTITION_POSITION HIGH_VALUE

------------------------------ ------------------ ----------------------------------------------------------------

P1                                              1 20200501

SYS_P6446                                       2 20210701

SYS_P7066                                       3 20210801

SYS_P7686                                       4 20210901

SYS_P8326                                       5 20211001

SYS_P8926                                       6 20211101

SYS_P9546                                       7 20211201

SYS_P10146                                      8 20211301

SYS_P10786                                      9 20220201

SYS_P11406                                     10 20220301

SYS_P11966                                     11 20220401

SYS_P12586                                     12 20220501

SYS_P13186                                     13 20220601

SYS_P13806                                     14 20220701

SYS_P14391                                     15 20220801

15 rows selected.


4.Take the index details and its status using below query.

select index_name,status,degree from dba_indexes where table_name='EASYINVOICE';

SQL> select index_name,status,degree from dba_indexes where table_name='EASYINVOICE';


INDEX_NAME                     STATUS   DEGREE

------------------------------ -------- ----------------------------------------

EASY_NDX211              VALID    1

INDX_EASY411             VALID    1

IND_TRAN_UDATE_TIME11          VALID    1

IK_EASY_ORGDEV11         VALID    1

EASY_NDX11               VALID    1

NDX_EASY311              VALID    1

6 rows selected.

5.Drop the partition which is older than 6 month using below command.

SQL> alter table EASYOWNER.EASYINVOICE drop partition SYS_P6446;

Table altered.

SQL> alter table EASYOWNER.EASYINVOICE drop partition SYS_P7066;

Table altered.

SQL> alter table EASYOWNER.EASYINVOICE drop partition SYS_P7686;

Table altered.

SQL> alter table EASYOWNER.EASYINVOICE drop partition SYS_P8326;

Table altered.

SQL> alter table EASYOWNER.EASYINVOICE drop partition SYS_P8926;

Table altered.

SQL> alter table EASYOWNER.EASYINVOICE drop partition SYS_P9546;

Table altered.

SQL>

SQL> col PARTITION_NAME for a30

select PARTITION_NAME,PARTITION_POSITION,HIGH_VALUE from dba_tab_partitions where TABLE_NAME='EASYINVOICE';


SQL>

PARTITION_NAME                 PARTITION_POSITION HIGH_VALUE

------------------------------ ------------------ --------------------------------------------------------------------------------

P1                                              1 20200501

SYS_P10146                                      2 20211301

SYS_P10786                                      3 20220201

SYS_P11406                                      4 20220301

SYS_P11966                                      5 20220401

SYS_P12586                                      6 20220501

SYS_P13186                                      7 20220601

SYS_P13806                                      8 20220701

SYS_P14391                                      9 20220801

9 rows selected.

SQL> SQL>


6.Rebuild the indexes using below command(User parallel based on the server utilization)

SQL> select index_name,status,degree from dba_indexes where table_name='EASYINVOICE';


INDEX_NAME                     STATUS   DEGREE

------------------------------ -------- ----------------------------------------

EASY_NDX211              UNUSABLE 1

INDX_EASY411             UNUSABLE 1

IND_TRAN_UDATE_TIME11          UNUSABLE 1

IK_EASY_ORGDEV11         UNUSABLE 1

EASY_NDX11               UNUSABLE 1

NDX_EASY311              UNUSABLE 1


6 rows selected.

SQL> alter index EASYOWNER.EASY_NDX211 rebuild parallel 6;

Index altered.

SQL> alter index EASYOWNER.INDX_EASY411 rebuild parallel 6;

Index altered.

SQL> alter index EASYOWNER.IND_TRAN_UDATE_TIME11 rebuild parallel 6;

Index altered.

SQL> alter index EASYOWNER.IK_EASY_ORGDEV11 rebuild parallel 6;

Index altered.

SQL> alter index EASYOWNER.EASY_NDX11 rebuild parallel 6;

Index altered.

SQL> alter index EASYOWNER.NDX_EASY311 rebuild parallel 6;

Index altered.

SQL>

7.After rebuild change the parallel to noparallel.


SQL> alter index EASYOWNER.EASY_NDX211  noparallel ;

alter index EASYOWNER.INDX_EASY411  noparallel ;

alter index EASYOWNER.IND_TRAN_UDATE_TIME11  noparallel ;

alter index EASYOWNER.IK_EASY_ORGDEV11  noparallel ;

alter index EASYOWNER.EASY_NDX11  noparallel ;

alter index EASYOWNER.NDX_EASY311  noparallel ;

Index altered.

SQL>

Index altered.

SQL>

Index altered.

SQL>

Index altered.

SQL>

Index altered.

SQL>

Index altered.

SQL>

8.Take out the size of the tables and status of indexes.


select index_name,status,degree from dba_indexes where table_name='EASYINVOICE';

SQL> select index_name,status,degree from dba_indexes where table_name='EASYINVOICE';


INDEX_NAME                     STATUS   DEGREE

------------------------------ -------- ----------------------------------------

EASY_NDX211              VALID    1

INDX_EASY411             VALID    1

IND_TRAN_UDATE_TIME11          VALID    1

IK_EASY_ORGDEV11         VALID    1

EASY_NDX11               VALID    1

NDX_EASY311              VALID    1

6 rows selected.


SQL>




Procedure for EASYTABLE Partitioning Realtime Example



Database Name        : EASYDB 

Server Name            : EASYSERVER

 

Summary: EASYDB partitioning is a monthly activity to be performed by the DBA

team every month. The 6 months old partitions are to be dropped and new

partitions for the month ahead have to be created. The partitions should be

created before the end of last week of every month.

 

Mandatory Steps:

 

Ø  On EASYSERVER, the scripts required for creating the partitions are located in /opt/app/oracle/scripts/partitions

 

1.    Login as Oracle user and cd to /opt/app/oracle/scripts/partitions

2.    Before starting, the oldest month’s partition has to be dropped before proceeding. Amend the drop_partitions.sql script to drop the 6 month old partition.

drop_partitions.sql

alter table EASYDB.INVOICE drop partition APR10 update global indexes;

alter table EASYDB.INVOICEITEM drop partition APR10 update global indexes;

alter table EASYDB.STATEMENT drop partition APR10 update global indexes;

alter table EASYDB.EASYTABLESPACE  drop partition APR10 update global indexes;

 

3.    Check if the relevant tablespaces (EASYTABLESPACE_month_DAT and EASYTABLESPACE_month_IND) are empty by querying dba_segments.

 

SQL> Select count(*) from dba_segments where tablespace_name=&tbs;

 

Select count(*) from dba_segments where tablespace_name='EASYTABLESPACE_APR_DAT';

Select count(*) from dba_segments where tablespace_name='EASYTABLESPACE_APR_IND';

 

4.    Make a note of which filesystems on which we have deleted the oldest month tablespace.

 

select file_name,AUTOEXTENSIBLE,bytes/1024/1024 from dba_data_files where tablespace_name='EASYTABLESPACE_APR_DAT’;

 

select file_name,AUTOEXTENSIBLE,bytes/1024/1024 from dba_data_files   where tablespace_name='EASYTABLESPACE_APR_IND';

5.    After confirming that the tablespace doesn’t contain any data. the 6 month oldest tablespaces and datafiles should be dropped. Amend the drop_tablespaces.sql scripts to drop the oldest tablespaces and execute it.

 

drop tablespace EASYTABLESPACE_APR_DAT including contents and datafiles;

drop tablespace EASYTABLESPACE_APR_IND including contents and datafiles;

6.    Wait a few minutes as there is sometimes a delay before the filesystems show the newly available space.

 7.    Create a new DATA tablespace (with 5 autoextensible datafile using minimum size 256 MB autoextend on next 128 Mb with maxsize 32 Gigs) by amending the create_data_tablespace.sql to reflect the next month. Make sure to edit both the tablespace name and the datafile name to reflect the new month and the datafiles to be created on the filesystem identified in step 4.

 

CREATE TABLESPACE EASYTABLESPACE_NOV_DAT

DATAFILE '/data/EASYDB/p05/EASYTABLESPACE_NOV_dat_01.dbf' SIZE 256m AUTOEXTEND ON NEXT 128M MAXSIZE 32000M

EXTENT MANAGEMENT LOCAL UNIFORM SIZE 131072K

LOGGING

ONLINE

SEGMENT SPACE MANAGEMENT AUTO

/

ALTER TABLESPACE EASYTABLESPACE_NOV_DAT

ADD DATAFILE '/data/EASYDB/p05/EASYTABLESPACE_NOV_dat_02.dbf' SIZE 256m AUTOEXTEND ON NEXT 128M MAXSIZE 32000M

/

ALTER TABLESPACE EASYTABLESPACE_NOV_DAT

ADD DATAFILE '/data/EASYDB/p05/EASYTABLESPACE_NOV_dat_03.dbf' SIZE 256m AUTOEXTEND ON NEXT 128M MAXSIZE 32000M

/

ALTER TABLESPACE EASYTABLESPACE_NOV_DAT

ADD DATAFILE '/data/EASYDB/p05/EASYTABLESPACE_NOV_dat_04.dbf' SIZE 256m AUTOEXTEND ON NEXT 128M MAXSIZE 32000M

/

ALTER TABLESPACE EASYTABLESPACE_NOV_DAT

ADD DATAFILE '/data/EASYDB/p05/EASYTABLESPACE_NOV_dat_05.dbf' SIZE 256m AUTOEXTEND ON NEXT 128M MAXSIZE 32000M

  

 8.    Create the index tablespace by amending create_index_tablespace.sql script and execute both scripts modified in step 7 and step 8.

 

CREATE TABLESPACE EASYTABLESPACE_NOV_IND

DATAFILE '/data/EASYDB/p05/EASYTABLESPACE_NOV_ind_01.dbf' SIZE 256m AUTOEXTEND ON NEXT 128M MAXSIZE 32000M

EXTENT MANAGEMENT LOCAL UNIFORM SIZE 131072K LOGGING ONLINE

SEGMENT SPACE MANAGEMENT AUTO

/

ALTER TABLESPACE EASYTABLESPACE_NOV_IND

ADD DATAFILE '/data/EASYDB/p05/EASYTABLESPACE_NOV_ind_02.dbf' SIZE 256m AUTOEXTEND ON NEXT 128M MAXSIZE 32000M

/

ALTER TABLESPACE EASYTABLESPACE_NOV_IND

ADD DATAFILE '/data/EASYDB/p05/EASYTABLESPACE_NOV_ind_03.dbf' SIZE 256m AUTOEXTEND ON NEXT 128M MAXSIZE 32000M

/

ALTER TABLESPACE EASYTABLESPACE_NOV_IND

ADD DATAFILE '/data/EASYDB/p05/EASYTABLESPACE_NOV_ind_04.dbf' SIZE 256m AUTOEXTEND ON NEXT 128M MAXSIZE 32000M

/

ALTER TABLESPACE EASYTABLESPACE_NOV_IND

ADD DATAFILE '/data/EASYDB/p05/EASYTABLESPACE_NOV_ind_05.dbf' SIZE 256m AUTOEXTEND ON NEXT 128M MAXSIZE 32000M

/

 9.    Now create the new partitions by amending add_partitions.sql scripts fo reflect the month ahead.

 

alter table EASYDB.invoice add

 PARTITION NOV10 VALUES LESS THAN (TO_DATE(' 2010-12-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))

    PCTUSED 0

    TABLESPACE EASYTABLESPACE_NOV_DAT

    (SUBPARTITION NOV10_BTC VALUES('BTC') TABLESPACE EASYTABLESPACE_NOV_DAT,

     SUBPARTITION NOV10_FIX VALUES('FIX') TABLESPACE EASYTABLESPACE_NOV_DAT,

     SUBPARTITION NOV10_VFM VALUES('VFM') TABLESPACE EASYTABLESPACE_NOV_DAT,

     SUBPARTITION NOV10_VTM VALUES('VTM') TABLESPACE EASYTABLESPACE_NOV_DAT,

     SUBPARTITION NOV10_TMB VALUES('TMB') TABLESPACE EASYTABLESPACE_NOV_DAT)

/

 

alter table EASYDB.invoiceitem add

 PARTITION NOV10 VALUES LESS THAN (TO_DATE(' 2010-12-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))

    PCTUSED 0

    TABLESPACE EASYTABLESPACE_NOV_DAT

    (SUBPARTITION NOV10_BTC VALUES('BTC') TABLESPACE EASYTABLESPACE_NOV_DAT,

     SUBPARTITION NOV10_FIX VALUES('FIX') TABLESPACE EASYTABLESPACE_NOV_DAT,

     SUBPARTITION NOV10_VFM VALUES('VFM') TABLESPACE EASYTABLESPACE_NOV_DAT,

     SUBPARTITION NOV10_VTM VALUES('VTM') TABLESPACE EASYTABLESPACE_NOV_DAT,

     SUBPARTITION NOV10_TMB VALUES('TMB') TABLESPACE EASYTABLESPACE_NOV_DAT)

/

 

alter table EASYDB.statement add

 PARTITION NOV10 VALUES LESS THAN (TO_DATE(' 2010-12-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))

    PCTUSED 0

    TABLESPACE EASYTABLESPACE_NOV_DAT

    (SUBPARTITION NOV10_BTC VALUES('BTC') TABLESPACE EASYTABLESPACE_NOV_DAT,

     SUBPARTITION NOV10_FIX VALUES('FIX') TABLESPACE EASYTABLESPACE_NOV_DAT,

     SUBPARTITION NOV10_VFM VALUES('VFM') TABLESPACE EASYTABLESPACE_NOV_DAT,

     SUBPARTITION NOV10_VTM VALUES('VTM') TABLESPACE EASYTABLESPACE_NOV_DAT,

     SUBPARTITION NOV10_TMB VALUES('TMB') TABLESPACE EASYTABLESPACE_NOV_DAT)

/

 

alter table EASYDB.EASYTABLESPACE add

 PARTITION NOV10 VALUES LESS THAN (TO_DATE(' 2010-12-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))

    PCTUSED 0

    TABLESPACE EASYTABLESPACE_NOV_DAT

    (SUBPARTITION NOV10_BTC VALUES('BTC') TABLESPACE EASYTABLESPACE_NOV_DAT,

     SUBPARTITION NOV10_FIX VALUES('FIX') TABLESPACE EASYTABLESPACE_NOV_DAT,

     SUBPARTITION NOV10_VFM VALUES('VFM') TABLESPACE EASYTABLESPACE_NOV_DAT,

     SUBPARTITION NOV10_VTM VALUES('VTM') TABLESPACE EASYTABLESPACE_NOV_DAT,

     SUBPARTITION NOV10_TMB VALUES('TMB') TABLESPACE EASYTABLESPACE_NOV_DAT)

/

 

 

10) Finally amend the alter_index.sql for the next month and run it.

 

alter index EASYDB.invoiceitemI2 rebuild subpartition NOV10_BTC tablespace EASYTABLESPACE_NOV_IND;

alter index EASYDB.invoiceitemI2 rebuild subpartition NOV10_FIX tablespace EASYTABLESPACE_NOV_IND;

alter index EASYDB.invoiceitemI2 rebuild subpartition NOV10_VFM tablespace EASYTABLESPACE_NOV_IND;

alter index EASYDB.invoiceitemI2 rebuild subpartition NOV10_VTM tablespace EASYTABLESPACE_NOV_IND;

alter index EASYDB.invoiceitemI2 rebuild subpartition NOV10_TMB tablespace EASYTABLESPACE_NOV_IND;

 

alter index EASYDB.invoiceitemI3 rebuild subpartition NOV10_BTC tablespace EASYTABLESPACE_NOV_IND;

alter index EASYDB.invoiceitemI3 rebuild subpartition NOV10_FIX tablespace EASYTABLESPACE_NOV_IND;

alter index EASYDB.invoiceitemI3 rebuild subpartition NOV10_VFM tablespace EASYTABLESPACE_NOV_IND;

alter index EASYDB.invoiceitemI3 rebuild subpartition NOV10_VTM tablespace EASYTABLESPACE_NOV_IND;

alter index EASYDB.invoiceitemI3 rebuild subpartition NOV10_TMB tablespace EASYTABLESPACE_NOV_IND;

 

alter index EASYDB.invoiceitemp1 rebuild subpartition NOV10_BTC tablespace EASYTABLESPACE_NOV_IND;

alter index EASYDB.invoiceitemp1 rebuild subpartition NOV10_FIX tablespace EASYTABLESPACE_NOV_IND;

alter index EASYDB.invoiceitemp1 rebuild subpartition NOV10_VFM tablespace EASYTABLESPACE_NOV_IND;

alter index EASYDB.invoiceitemp1 rebuild subpartition NOV10_VTM tablespace EASYTABLESPACE_NOV_IND;

alter index EASYDB.invoiceitemp1 rebuild subpartition NOV10_TMB tablespace EASYTABLESPACE_NOV_IND;

 

alter index EASYDB.statementI2 rebuild subpartition NOV10_BTC tablespace EASYTABLESPACE_NOV_IND;

alter index EASYDB.statementI2 rebuild subpartition NOV10_FIX tablespace EASYTABLESPACE_NOV_IND;

alter index EASYDB.statementI2 rebuild subpartition NOV10_VFM tablespace EASYTABLESPACE_NOV_IND;

alter index EASYDB.statementI2 rebuild subpartition NOV10_VTM tablespace EASYTABLESPACE_NOV_IND;

alter index EASYDB.statementI2 rebuild subpartition NOV10_TMB tablespace EASYTABLESPACE_NOV_IND;

 

alter index EASYDB.statementI3 rebuild subpartition NOV10_BTC tablespace EASYTABLESPACE_NOV_IND;

alter index EASYDB.statementI3 rebuild subpartition NOV10_FIX tablespace EASYTABLESPACE_NOV_IND;

alter index EASYDB.statementI3 rebuild subpartition NOV10_VFM tablespace EASYTABLESPACE_NOV_IND;

alter index EASYDB.statementI3 rebuild subpartition NOV10_VTM tablespace EASYTABLESPACE_NOV_IND;

alter index EASYDB.statementI3 rebuild subpartition NOV10_TMB tablespace EASYTABLESPACE_NOV_IND;

 

alter index EASYDB.statementp1 rebuild subpartition NOV10_BTC tablespace EASYTABLESPACE_NOV_IND;

alter index EASYDB.statementp1 rebuild subpartition NOV10_FIX tablespace EASYTABLESPACE_NOV_IND;

alter index EASYDB.statementp1 rebuild subpartition NOV10_VFM tablespace EASYTABLESPACE_NOV_IND;

alter index EASYDB.statementp1 rebuild subpartition NOV10_VTM tablespace EASYTABLESPACE_NOV_IND;

alter index EASYDB.statementp1 rebuild subpartition NOV10_TMB tablespace EASYTABLESPACE_NOV_IND;

 

alter index EASYDB.EASYTABLESPACEI2 rebuild subpartition NOV10_BTC tablespace EASYTABLESPACE_NOV_IND;

alter index EASYDB.EASYTABLESPACEI2 rebuild subpartition NOV10_FIX tablespace EASYTABLESPACE_NOV_IND;

alter index EASYDB.EASYTABLESPACEI2 rebuild subpartition NOV10_VFM tablespace EASYTABLESPACE_NOV_IND;

alter index EASYDB.EASYTABLESPACEI2 rebuild subpartition NOV10_VTM tablespace EASYTABLESPACE_NOV_IND;

alter index EASYDB.EASYTABLESPACEI2 rebuild subpartition NOV10_TMB tablespace EASYTABLESPACE_NOV_IND;

 

 

alter index EASYDB.EASYTABLESPACEp1 rebuild subpartition NOV10_BTC tablespace EASYTABLESPACE_NOV_IND;

alter index EASYDB.EASYTABLESPACEp1 rebuild subpartition NOV10_FIX tablespace EASYTABLESPACE_NOV_IND;

alter index EASYDB.EASYTABLESPACEp1 rebuild subpartition NOV10_VFM tablespace EASYTABLESPACE_NOV_IND;

alter index EASYDB.EASYTABLESPACEp1 rebuild subpartition NOV10_VTM tablespace EASYTABLESPACE_NOV_IND;

alter index EASYDB.EASYTABLESPACEp1 rebuild subpartition NOV10_TMB tablespace EASYTABLESPACE_NOV_IND;

 

 

 

 

10. Send and email to the team to let them know the work is done.

 

Note1: All the text in blue color will be changed month after month during partition activity.

 

Note 2: Though there is not enough space to grow all datafiles upto 32 Gigs, we have made them autoextensible upto 32 Gigs to accomodate the maximum space required by both DATA and INDEX tablespace, also we have added new metrics in OEM to monitor the file system space usage (P01 to P07) 80% warning and 90% critical to avoid the space crunch in advance


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