I created a partitioned table with the below command:
create table A
(
ID number(10),
SUBSCRIBER_TYPE varchar2(20)
,
SSN varchar2(20)
)
ENABLE ROW MOVEMENT
INITRANS 4 STORAGE(FREELISTS 16)
PARTITION BY LIST (SUBSCRIBER_TYPE)
(
PARTITION P000 VALUES(0),
PARTITION P001 VALUES(1),
PARTITION P002 VALUES(2)
)
TABLESPACE TS_SUBSCRIBER01 ;
Now I need to change the column name SSN to SOCIAL_SECURITY_NUMBER and its datatype to number.
Can I use a simple ALTER command to modify the column of the table so that I it reflects the changes in all the partitions?
Yes you can use a simple alter command for the partitioned table.
Related
I am trying to create a table with partitions but, I constantly get the same error. The exact oracle version is 12.1.0.2.0
create table toys (
name varchar2(10),
weight number,
color varchar2(10),
PRIMARY KEY (name)
)
partition by list (color) partitions (
partition p_green values ('green'),
partition p_red values ('red')
);
Is there some other prerequisite that must be done before I can created a partitioned table ?
VALUES keyword is required:
create table toys (
name varchar2(10),
weight number,
color varchar2(10),
PRIMARY KEY (name)
)
partition by list (color) -- partitions -- removed
-- automatic
(
partition p_green VALUES('green'),
partition p_red VALUES('red')
--,partition p_def VALUES(DEFAULT)
);
db<>fiddle demo
I am facing issue with exchange partitioning and sub partitioning in Oracle.
Please explain with example.
Please find following example
CREATE TABLE DEPARTMENT
( DEPT_ID NUMBER(30,0) NOT NULL ENABLE,
IS_ACTIVE VARCHAR2(1 BYTE) NOT NULL ,
BUSINESS_DATE DATE NOT NULL ENABLE,
COMPANY_CODE VARCHAR2(4) DEFAULT 'C1' NOT NULL ,
CONSTRAINT PK_DEPARTMENT PRIMARY KEY (BUSINESS_DATE, COMPANY_CODE, DEPT_ID) ENABLE
)
PARTITION BY RANGE
(
BUSINESS_DATE
)
INTERVAL (
NUMTODSINTERVAL(1,'DAY')
)
SUBPARTITION BY LIST(COMPANY_CODE)
SUBPARTITION TEMPLATE
(
SUBPARTITION CMN_01 VALUES ('C1'),
SUBPARTITION CMN_02 VALUES ('C2'),
SUBPARTITION CMN_03 VALUES ('C3')
)
(
PARTITION DEFAULT_PART VALUES LESS THAN ('01-JAN-2012')
)
;
CREATE INDEX IDX1_DEPARTMENT ON DEPARTMENT (DEPT_ID, IS_ACTIVE);
CREATE TABLE TEMP_DEPARTMENT AS SELECT * FROM DEPARTMENT WHERE 1=2;
CREATE TABLE EMPLOYEE
( ID NUMBER(30,0) NOT NULL ENABLE,
DEPT_ID NUMBER(30,0) NOT NULL ENABLE,
BUSINESS_DATE DATE NOT NULL ENABLE,
COMPANY_CODE VARCHAR2(4) DEFAULT 'C1' NOT NULL,
CONSTRAINT PK_EMPLOYEE PRIMARY KEY (BUSINESS_DATE,COMPANY_CODE, ID) ENABLE,
CONSTRAINT FK1_EMPLOYEE_DEPT FOREIGN KEY (BUSINESS_DATE, COMPANY_CODE, DEPT_ID)
REFERENCES DEPARTMENT (BUSINESS_DATE, COMPANY_CODE, DEPT_ID) ENABLE NOVALIDATE
)
PARTITION BY RANGE
(
BUSINESS_DATE
)
INTERVAL (
NUMTODSINTERVAL(1,'DAY')
)
SUBPARTITION BY LIST(COMPANY_CODE)
SUBPARTITION TEMPLATE
(
SUBPARTITION CMN_01 VALUES ('C1'),
SUBPARTITION CMN_02 VALUES ('C2'),
SUBPARTITION CMN_03 VALUES ('C3')
)
(
PARTITION DEFAULT_PART VALUES LESS THAN ('01-JAN-2012')
);
Insert few thousands records into DEPARTMENT and EMPLOYEE tables for few partitions and their all sub partitions
select * from DEPARTMENT where BUSINESS_DATE='19-JAN-15' and COMPANY_CODE='C1';
select* from EMPLOYEE;
select * from all_tab_partitions where TABLE_OWNER='TEST' and
table_name='DEPARTMENT';
select * from ALL_TAB_SUBPARTITIONS where TABLE_OWNER='TEST' and
table_name='DEPARTMENT';
select * from all_tab_partitions where TABLE_OWNER='TEST' and
table_name='EMPLOYEE';
select * from ALL_TAB_SUBPARTITIONS where TABLE_OWNER='TEST' and
table_name='EMPLOYEE';
select * from TEMP_DEPARTMENT;
Exchange and Truncate sub partitions
1)Exchange sub partitioningALTER TABLE DEPARTMENT EXCHANGE SUBPARTITION SYS_SUBP7356 WITH TABLE TEMP_DEPARTMENT WITHOUT VALIDATION UPDATE GLOBAL INDEXES;
2) Truncate temp exchange table truncate table TEMP_DEPARTMENT;
3) Truncate sub partitioning (sub partition name from ALL_TAB_SUBPARTITIONS table) with global index update `ALTER TABLE DEPARTMENT TRUNCATE SUBPARTITION SYS_SUBP7356 DROP STORAGE UPDATE GLOBAL INDEXES;
Here the above 1 to 3 steps are executed for three sub-partitions
4) Get this partition name from all_tab_partitions table with global index update ALTER TABLE DEPARTMENT DROP PARTITION SYS_P7359 UPDATE GLOBAL INDEXES;
5) Truncate sub partitioning (sub partition name from ALL_TAB_SUBPARTITIONS table) with global index update ALTER TABLE EMPLOYEE TRUNCATE SUBPARTITION SYS_SUBP7360 DROP STORAGE UPDATE GLOBAL INDEXES;
Here the above 5 steps are executed for three sub-partitions
6) Get this partition name from all_tab_partitions table with global index update ALTER TABLE EMPLOYEE DROP PARTITION SYS_P7363 UPDATE GLOBAL INDEXES;
7) alter index PK_DEPARTMENT rebuild;
8) alter index IDX1_DEPARTMENT rebuild;
9) alter index PK_EMPLOYEE rebuild;
Steps 7 to 9 is require only when UPDATE GLOBAL INDEXES not used at the time of Altering Table for exchange, truncate and drop partition or sub partition
10)
begin
dbms_stats.gather_table_stats(ownname=>'TEST', tabname=>'DEPARTMENT', granularity=>'ALL' ,no_invalidate=>FALSE);
dbms_stats.gather_table_stats(ownname=>'TEST', tabname=>'EMPLOYEE', granularity=>'ALL' ,no_invalidate=>FALSE);
end;
UPDATE GLOBAL INDEXES is used at the time of Altering Table for exchange, truncate and drop partition or sub partition where global indexes are applied on that table then we can do DML operation on same table in parallel here.
UPDATE GLOBAL INDEXES is used to rebuild the indexes at same time with alter operation.
If UPDATE GLOBAL INDEXES is not used then DML operation is not allowed on same table in parallel. It will throw below ORA Exception for global indexes.
ERROR Message when perform insert operation after drop/exchange/truncate partition/sub partition from table:
SQL Error: ORA-01502: index 'TEST.PK_DEPARTMENT' or partition of such
index is in unusable state
01502. 00000 - "index '%s.%s' or partition of such index is in unusable state"
Cause: An attempt has been made to access an index or index partition that has been marked unusable by a direct load or by a DDL operation
Action: DROP the specified index, or REBUILD the specified index, or REBUILD the unusable index partition
If you don’t want to use UPDATE GLOBAL INDEXES and want parallel DML operation with purging then make indexes Local (must not contain primary key or unique constraint because it is default created global unique index). It’s on partition and sub partition and refers default table space.
With Local indexes you observed slow insertion on that table.
Assuming following table:
create table INVOICE(
INVOICE_ID NUMBER
,INVOICE_SK NUMBER
,INVOICE_AMOUNT NUMBER
,INVOICE_TEXT VARCHAR2(4000 Char)
,B2B_FLAG NUMBER -- 0 or 1
,ACTIVE NUMBER(1) -- 0 or 1
)
PARTITION BY LIST (ACTIVE)
SUBPARTITION BY LIST (B2B_FLAG)
( PARTITION p_active_1 values (1)
( SUBPARTITION sp_b2b_flag_11 VALUES (1)
, SUBPARTITION sp_b2b_flag_10 VALUES (0)
)
,
PARTITION p_active_0 values (0)
( SUBPARTITION sp_b2b_flag_01 VALUES (1)
, SUBPARTITION sp_b2b_flag_00 VALUES (0)
)
)
For perfomance reasons the table should get a "Composite List-List" partitioning, see http://docs.oracle.com/cd/E18283_01/server.112/e16541/part_admin001.htm#i1006565.
The problematic point is, that the ACTIVE-Flag will change requently for a huge amount of records and sometimes also the B2B_FLAG. Will Oracle automatically recognize the records, for which the partitioning value has changed and move them to the appropriate partion or do I have to call some kind of maintenance function, in order to reorganize the partitions?
You need to enable row movement on the table or the update statement will fail with ORA-14402: updating partition key column would cause a partition change.
See the following testcase:
create table T_TESTPART
(
pk number(10),
part_key number(10)
)
partition by list (part_key) (
partition p01 values (1),
partition p02 values (2),
partition pdef values (default)
);
alter table T_TESTPART
add constraint pk_pk primary key (PK);
Now insert a row and try to update the partitioning value:
insert into t_testpart values (1,1);
update t_testpart set part_key = 2 where pk = 1;
You will now get the Error mentioned above.
If you enable row movement, the same statement will work and oracle will move the row to the other partition:
alter table t_testpart enable row movement;
update t_testpart set part_key = 2 where pk = 1;
I did not do any performance tests, but Oracle will probably delete the row from the first partition and insert it to the second partition. Consider this when using it in large scale.
In my own databases, I usually only use partitioning on columns that do not change.
Further reading:
http://www.dba-oracle.com/t_callan_oracle_row_movement.htm
I have created a table as follows:
create table emp( emp_id number(5) primary key
, emp_name varchar(20) not null
, dob date );
After the table has been created how would I change the constraint not null to unique or any other constraint in SQL*Plus?
You don't change a constraint from one type to another. You can add a unique constraint to the table
ALTER TABLE emp
ADD ( COSTRAINT uk_emp_name UNIQUE( emp_name ) );
That is independent of whether emp_name is allowed to have NULL values.
Just use ALTER TABLE command. For details look here: http://docs.oracle.com/cd/B28359_01/server.111/b28286/statements_3001.htm#i2103817
We cant be able to modify the already added constraint. Just we have to drop the constraint and add the new one with the same name, but add it with the necessary changes.
ALTER TABLE table_name drop constraint contraint_name;
alter table tablename add constraint containt_name CHECK (column_name IN (changes in the contraint)) ENABLE;
Lets say i have a table with the following definition
create table dummy (col1 number(9) not null)
All the values in this dummy.col1 are 7 digit long. Now i want to reduce the length of this column from 9 - 7 using alter command. Oracle gives me error that column to be modified must be empty to decrease precision or scale. Makes sense.
I want to ask is there any work around to reduce the column size?
I can't delete the values in the column.
I can't copy values from this column to another since it has trillions of data.
The column size has no relationship to how the data is physically stored (they are variable length)
e.g. '23' in a number(2) will take exactly the same space if stored in a number(38)
It is purely a constraint on the maximum number that can be stored in the column therefore you could just add a constraint on the column:
ALTER TABLE dummy ADD
CONSTRAINT c1
CHECK (col1 < 9999999)
ENABLE
VALIDATE;
if you want it to go a little quicker change VALIDATE to NOVALIDATE obviously this will not check the validity of the existing data.
Kevin's answer is excellent.
The only other way to do it is to
rename the existing column,
create a new column with the old name and the new size,
issue an update statement to populate the new field (which you said you cannot do)
and then drop the renamed column.
Are you sure you cannot find some downtime one weekend to perform this task ?
Solution #1
My solution below keeps the original column order.
I found that to be important, especially if there are canned SQL statements out
there (middle tier, client tier) that point back to your database that do implicit
SELECTs.
i.e.
SELECT *
FROM tableName
WHERE ...;
INSERT INTO copyTableName(column1,column2,column3,...)
SELECT *
FROM tableName
WHERE ...;
Here goes:
Generate the DDLs for
1. The table containing the column you intend to resize
2. All the relationship constraints, indexes, check constraints, triggers that reference that table.
3. All the foreign keys of other tables that reference the primary key of this table.
Make sure each table-referencing-object DDL is stand-alone, separate from the
CREATE TABLE DDL.
You'll have something like
/* 1. The table containing the column you intend to resize */
CREATE TABLE tableName
(
column1 TYPE(size) [DEFAULT value] [NOT] NULL,
column2 TYPE(size) [DEFAULT value] [NOT] NULL,
column3 TYPE(size) [DEFAULT value] [NOT] NULL,
...
)
TABLESPACE tsName
[OPTIONS];
/* 2. All the relationship constraints, indexes, check constraints, triggers that reference that table. */
CREATE INDEX indexName ON tableName
(column1)
NOLOGGING
TABLESPACE INDX
NOPARALLEL;
CREATE INDEX compositeIndexName ON tableName
(column1,column2,...)
NOLOGGING
TABLESPACE INDX
NOPARALLEL;
CREATE UNIQUE INDEX pkName ON tableName
(column2)
NOLOGGING
TABLESPACE INDX
NOPARALLEL;
ALTER TABLE tableName ADD (
CHECK (column4 IS NOT NULL));
ALTER TABLE tableName ADD (
CONSTRAINT pkName
PRIMARY KEY
(column2)
USING INDEX
TABLESPACE INDX);
ALTER TABLE tableName ADD (
CONSTRAINT fkName
FOREIGN KEY (column2)
REFERENCES otherTable (column2));
/* 3. All the foreign keys of other tables that reference the primary key of this table. */
ALTER TABLE otherTableName ADD (
CONSTRAINT otherTableFkName
FOREIGN KEY (otherTableColumn2)
REFERENCES tableName (column1));
Copy out just the CREATE TABLE statement, change the table name and
reduce the size of the column you wish to modify:
CREATE TABLE tableName_YYYYMMDD
(
column1 TYPE(size) [DEFAULT value] [NOT] NULL,
column2 TYPE(reducedSize) [DEFAULT value] [NOT] NULL,
column3 TYPE(size) [DEFAULT value] [NOT] NULL,
...
)
TABLESPACE tsName
[OPTIONS];
Insert the data from tableName into tableName_YYYYMMDD:
INSERT /* APPEND */ INTO tableName_YYYYMMDD(
column1 ,
column2 ,
column3 ,
... )
SELECT
column1 ,
column2 ,
column3 ,
...
FROM tableName;
COMMIT;
Drop all objects referencing the original table.
Also, drop all foreign keys that reference the tableName primary key pkName.
Don't worry, you've saved the DDL so you'll be able to recreate them.
Notice that I drop indexes after copying the data out of tableName.
I do this because perhaps one of the indexes will be used in the
above SELECT so that operation will complete faster.
DROP INDEX indexName ;
DROP INDEX compositeIndexName ;
DROP UNIQUE INDEX pkName ;
ALTER TABLE tableName DROP CONSTRAINT pkName ;
ALTER TABLE tableName DROP CONSTRAINT fkName ;
ALTER TABLE otherTableName DROP CONSTRAINT otherTableFkName ;
Drop the original table.
DROP TABLE tableName;
Rename the new table.
ALTER TABLE tableName_YYYYMMDD RENAME TO tableName;
Recreate all referencing objects from the DDL statements you saved before.
/* 2. All the relationship constraints, indexes, check constraints, triggers that reference that table. */
CREATE INDEX indexName ON tableName
(column1)
NOLOGGING
TABLESPACE INDX
NOPARALLEL;
CREATE INDEX compositeIndexName ON tableName
(column1,column2,...)
NOLOGGING
TABLESPACE INDX
NOPARALLEL;
CREATE UNIQUE INDEX pkName ON tableName
(column2)
NOLOGGING
TABLESPACE INDX
NOPARALLEL;
ALTER TABLE tableName ADD (
CHECK (column4 IS NOT NULL));
ALTER TABLE tableName ADD (
CONSTRAINT pkName
PRIMARY KEY
(column2)
USING INDEX
TABLESPACE INDX);
ALTER TABLE tableName ADD (
CONSTRAINT fkName
FOREIGN KEY (column2)
REFERENCES otherTable (column2));
/* 3. All the foreign keys of other tables that reference the primary key of this table. */
ALTER TABLE otherTableName ADD (
CONSTRAINT otherTableFkName
FOREIGN KEY (otherTableColumn2)
REFERENCES tableName (column1));
Solution #2
Keep the column order but do not rebuild non-unique-used-by-PK indexes that might contain column2.
ALTER TABLE tableName ADD (column2Copy TYPE(reducedSize));
UPDATE tableName SET column2Copy = column2;
ALTER TABLE tableName MODIFY (column2 TYPE(size) NULL);
ALTER TABLE tableName DROP CONSTRAINT pkName;
DROP INDEX pkName;
UPDATE tableName SET column2 = null;
ALTER TABLE tableName MODIFY (column2 TYPE(reducedSize));
UPDATE tableName SET column2 = column2Copy;
ALTER TABLE tableName DROP COLUMN column2Copy;
CREATE UNIQUE INDEX pkName ON tableName
(column2)
NOLOGGING
TABLESPACE INDX
NOPARALLEL;
ALTER TABLE tableName ADD (
CONSTRAINT pkName
PRIMARY KEY
(column2)
USING INDEX
TABLESPACE INDX);
COMMIT;