I have multiple partitions on my table as below.
Partition- Day_20190509 with high value of 20190510
Partition- Day_20190520 with high value of 20190521
Partition- Day_99999999 with MAXVALUE as high.
I want to create three new partitions for Day_20190510,Day_20190513,Day_20190514 with high values as 20190513,20190514,20190520 respectively.
I believe this can done using SPLIT partitions but could not understand how I can create partitions in between. Can someone assist with the query for this?
I tried using partition split option but could not understand what will be my range part and new partitions
ALTER TABLE table_name SPLIT PARTITION partition_name
AT (range_part_value)
INTO
(
PARTITION new_part1
[TABLESPACE tablespace_name],
PARTITION new_part2
[TABLESPACE tablespace_name]
);
Values you described as high values (20190513,20190514,20190520) in new partitions (Day_20190510,Day_20190513,Day_20190514) belong to the current partition: Day_20190520 (Value range: 20190511 - 20190521)
So current partition Day_20190520 must be split as follows:
ALTER TABLE table_name SPLIT PARTITION Day_20190520 INTO
(PARTITION Day_20190510 VALUES LESS THAN (20190514), -- 20190513 + 1
PARTITION Day_20190513 VALUES LESS THAN (20190515), -- 20190514 + 1
PARTITION Day_20190514 VALUES LESS THAN (20190521), -- 20190520 + 1
PARTITION Day_20190520_1);
Hope this will solve your problem.
Related
CREATE TABLE temp_stud as select * from STUD_MAST
PARTITION BY RANGE(ADM_DT)
(
PARTITION temp_stud1 VALUES LESS THAN(TO_DATE('02/01/2000','MM/DD/YYYY')),
PARTITION temp_stud2 VALUES LESS THAN(TO_DATE('03/01/2000','MM/DD/YYYY')),
PARTITION temp_stud3 VALUES LESS THAN(TO_DATE('04/01/2000','MM/DD/YYYY')),
PARTITION temp_stud4 VALUES LESS THAN(TO_DATE('05/01/2000','MM/DD/YYYY'))
);
I am getting a missing left parenthesis error for above table creation can anyone tell me what is the issue in above creation
Note: ADM_DT is a date column with data type char(8) and storing format YYMMDD
Please use below SQL. The Creation of Partition has be part of Create table.
CREATE TABLE temp_stud
PARTITION BY RANGE(ADM_DT)
(
PARTITION temp_stud1 VALUES LESS THAN(TO_DATE('02/01/2000','MM/DD/YYYY')),
PARTITION temp_stud2 VALUES LESS THAN(TO_DATE('03/01/2000','MM/DD/YYYY')),
PARTITION temp_stud3 VALUES LESS THAN(TO_DATE('04/01/2000','MM/DD/YYYY')),
PARTITION temp_stud4 VALUES LESS THAN(TO_DATE('05/01/2000','MM/DD/YYYY'))
)
as select * from STUD_MAST;
I have a table with 2017 and 2018 year data. Need to create monthly partition on that table.
So I created one non partitioned table and loaded all the data from original table. now I am converting the new table to a monthly partitioned table.
When I am altering getting error as
ORA-14300: partitioning key maps to a partition outside maximum
permitted number of partitions
My Script is
ALTER TABLE ORDERHDR_PART MODIFY
PARTITION BY RANGE (LASTUPDATE) INTERVAL(NUMTOYMINTERVAL(1, 'MONTH'))
(
PARTITION ORDERHDR_PART_JAN VALUES less than (TO_DATE('01-02-2018','DD-MM-YYYY')),
PARTITION ORDERHDR_PART_FEB VALUES less than (TO_DATE('01-03-2018','DD-MM-YYYY')),
PARTITION ORDERHDR_PART_MAR VALUES less than (TO_DATE('01-04-2018','DD-MM-YYYY')),
PARTITION ORDERHDR_PART_APR VALUES less than (TO_DATE('01-05-2018','DD-MM-YYYY')),
PARTITION ORDERHDR_PART_MAY VALUES less than (TO_DATE('01-06-2018','DD-MM-YYYY')),
PARTITION ORDERHDR_PART_JUN VALUES less than (TO_DATE('01-07-2018','DD-MM-YYYY')),
PARTITION ORDERHDR_PART_JUL VALUES less than (TO_DATE('01-08-2018','DD-MM-YYYY')),
PARTITION ORDERHDR_PART_AUG VALUES less than (TO_DATE('01-09-2018','DD-MM-YYYY')),
PARTITION ORDERHDR_PART_SEP VALUES less than (TO_DATE('01-10-2018','DD-MM-YYYY')),
PARTITION ORDERHDR_PART_OCT VALUES less than (TO_DATE('01-11-2018','DD-MM-YYYY')),
PARTITION ORDERHDR_PART_NOV VALUES less than (TO_DATE('01-12-2018','DD-MM-YYYY')),
PARTITION ORDERHDR_PART_DEC VALUES less than (TO_DATE('01-01-2019','DD-MM-YYYY'))
)ONLINE;
I think your approach is wrong.
First create a partitioned table, e.g.
CREATE TABLE ORDERHDR_PART (....)
PARTITION BY RANGE (LASTUPDATE) INTERVAL (NUMTOYMINTERVAL(1, 'MONTH'))
(
PARTITION ORDERHDR_INITIAL VALUES less than (DATE '2000-01-01')
);
Then transfer existing data to the new table.
Either you use a simple INSERT INTO ORDERHDR_PART SELECT * FROM ORDERHDR_2017;
Oracle will create monthly partitions automatically based on LASTUPDATE value.
With this methods you would duplicate (temporary) your data and/or you may face a performance issue.
The other method is to use Exchanging Partitions, should be like this
ALTER TABLE ORDERHDR_PART
EXCHANGE PARTITION FOR (DATE '2017-01-01')
WITH TABLE ORDERHDR_2017
INCLUDING INDEXES;
I don't know whether "PARTITION FOR (DATE '2017-01-01')" is created automatically, perhaps you have to run INSERT INTO ORDERHDR_PART (LASTUPDATE) VALUES (DATE '2017-01-01'); ROLLBACK; in order to create it first.
You will get one partition for all months, afterwards you can split the partition with Splitting into Multiple Partitions. Should be like this:
ALTER TABLE ORDERHDR_PART SPLIT PARTITION FOR (DATE '2017-01-01') INTO (
PARTITION ORDERHDR_PART_JAN VALUES less than (TO_DATE('01-02-2018','DD-MM-YYYY')),
PARTITION ORDERHDR_PART_FEB VALUES less than (TO_DATE('01-03-2018','DD-MM-YYYY')),
PARTITION ORDERHDR_PART_MAR VALUES less than (TO_DATE('01-04-2018','DD-MM-YYYY')),
PARTITION ORDERHDR_PART_APR VALUES less than (TO_DATE('01-05-2018','DD-MM-YYYY')),
PARTITION ORDERHDR_PART_MAY VALUES less than (TO_DATE('01-06-2018','DD-MM-YYYY')),
PARTITION ORDERHDR_PART_JUN VALUES less than (TO_DATE('01-07-2018','DD-MM-YYYY')),
PARTITION ORDERHDR_PART_JUL VALUES less than (TO_DATE('01-08-2018','DD-MM-YYYY')),
PARTITION ORDERHDR_PART_AUG VALUES less than (TO_DATE('01-09-2018','DD-MM-YYYY')),
PARTITION ORDERHDR_PART_SEP VALUES less than (TO_DATE('01-10-2018','DD-MM-YYYY')),
PARTITION ORDERHDR_PART_OCT VALUES less than (TO_DATE('01-11-2018','DD-MM-YYYY')),
PARTITION ORDERHDR_PART_NOV VALUES less than (TO_DATE('01-12-2018','DD-MM-YYYY')),
PARTITION ORDERHDR_PART_DEC VALUES less than (TO_DATE('01-01-2019','DD-MM-YYYY'))
);
Note, by default you cannot drop the inital partition of a RANGE partitioned table. If you face this problem execute:
ALTER TABLE ORDERHDR_PART SET INTERVAL ();
ALTER TABLE ORDERHDR_PART DROP PARTITION ORDERHDR_INITIAL;
ALTER TABLE ORDERHDR_PART SET INTERVAL (NUMTOYMINTERVAL(1, 'MONTH'));
I would like to run a procedure that merges table partitions that match a certain criteria.
As example - table1 is range partitions by date and has 5 partitions.
Partitions = empire1, empire2, rebels1, rebels2, yoda1.
Table DESC:
INVOICE_NO NOT NULL NUMBER
INVOICE_DATE NOT NULL DATE
COMMENTS VARCHAR2(500)
it is partitioned by INVOICE_DATE as follows
PARTITION REBELS1 VALUES LESS THAN (TO_DATE('01-JAN-2014','DD-MON-YYYY')),
PARTITION REBELS2 VALUES LESS THAN (TO_DATE('01-JAN-2015','DD-MON-YYYY')),
PARTITION EMPIRE1 VALUES LESS THAN (TO_DATE('01-JAN-2016','DD-MON-YYYY')),
PARTITION EMPIRE2 VALUES LESS THAN (TO_DATE('01-JAN-2017','DD-MON-YYYY')),
PARTITION YODA VALUES LESS THAN (TO_DATE('01-JAN-2018','DD-MON-YYYY')),
I need to grab all partitions named rebel% and yoda% and merge them into one new partition called 'jawa'.
In the end only 3 partitions would exist, empire1, empire2 and jawa.
For example, I have a table name Emp and it has empname, designation, salary as columns. I would like this table to have 2 partitions, like list of employees who are managers in one partition and rest(engineer, peon, clerk) in one partition.
can someone help on how to create it
In this case you will have to use LIST based partition. Create a pertition where ROLE = MANAGER and create another partition which is default. Here is an example which will help you.
Exclude values from oracle partition
Example
CREATE TABLE EMPLOYEE (EMP_ID VARCHAR2(25),
EMP_NAME VARCHAR2(250),
ROLE VARCHAR2(100)
)
PARTITION BY LIST (ROLE)
(
PARTITION part_managers
VALUES ('MANAGER'),
PARTITION part_others
VALUES (DEFAULT)
);
Please refer the following URL and example:
For example, the following SQL statement splits the sales_Q4_2007 partition of the partitioned by range table sales splits into five partitions corresponding to the quarters of the next year. In this example, the partition sales_Q4_2008 implicitly becomes the high bound of the split partition.
ALTER TABLE sales SPLIT PARTITION sales_Q4_2007 INTO
( PARTITION sales_Q4_2007 VALUES LESS THAN (TO_DATE('01-JAN-2008','dd-MON-yyyy')),
PARTITION sales_Q1_2008 VALUES LESS THAN (TO_DATE('01-APR-2008','dd-MON-yyyy')),
PARTITION sales_Q2_2008 VALUES LESS THAN (TO_DATE('01-JUL-2008','dd-MON-yyyy')),
PARTITION sales_Q3_2008 VALUES LESS THAN (TO_DATE('01-OCT-2008','dd-MON-yyyy')),
PARTITION sales_Q4_2008);
For the sample table customers partitioned by list, the following statement splits the partition Europe into three partitions.
ALTER TABLE list_customers SPLIT PARTITION Europe INTO
(PARTITION western-europe VALUES ('GERMANY', 'FRANCE'),
PARTITION southern-europe VALUES ('ITALY'),
PARTITION rest-europe);
https://docs.oracle.com/database/121/VLDBG/GUID-01C14320-0D7B-48BE-A5AD-003DDA761277.htm
You will get some idea about this.
I have a table with a columns 'A' and 'B'.
'A' is a column with 90% 'null' and 10% different values , and most of the time I query to have record with one or two of these different values.
and 'B' is a column with 90% value='1' and 10% different values and most of the time I query to have record with one or two of these different values.
In this table we have DML transaction most of the time.
now , I don't know define index on these columns is good? if yes which type of index?
In principle Bitmap Index would be the best in such situation. However, due to mulit-user environment they are not suitable - you would slow down your application significantly by table locks and perhaps get even dead-locks.
Maybe you can optimize your application by smart partitioning and usage of Partial Indexes (new feature in Oracle 12c)
CREATE TABLE statements below should be equivalent.
CREATE TABLE YOUR_TABLE (a INTEGER, b INTEGER, ... more COLUMNS)
PARTITION BY LIST (a) SUBPARTITION BY LIST (b) (
PARTITION part_a_NULL VALUES (NULL) (
SUBPARTITION part_a_NULL_b_1 VALUES (1) INDEXING OFF,
SUBPARTITION part_a_NULL_b_other VALUES (DEFAULT) INDEXING ON
),
PARTITION part_a_others VALUES (DEFAULT) (
SUBPARTITION part_a_others_b_1 VALUES (1) INDEXING OFF,
SUBPARTITION part_a_others_b_other VALUES (DEFAULT) INDEXING ON
)
);
CREATE TABLE YOUR_TABLE (a INTEGER, b INTEGER, ... more COLUMNS)
PARTITION BY LIST (a) SUBPARTITION BY LIST (b)
SUBPARTITION TEMPLATE (
SUBPARTITION b_1 VALUES (1) INDEXING OFF,
SUBPARTITION b_other VALUES (DEFAULT) INDEXING ON
)
(
PARTITION part_a_NULL VALUES (NULL),
PARTITION part_a_others VALUES (DEFAULT)
);
CREATE INDEX IND_A ON YOUR_TABLE (A) LOCAL INDEXING PARTIAL;
CREATE INDEX IND_B ON YOUR_TABLE (B) LOCAL INDEXING PARTIAL;
By this your index will consume only 10% of entire tablespace. If your WHERE condition is WHERE A IS NULL or WHERE B = 1 then Oracle optimizer would skip such indexes anyway.
Verify with this query
SELECT table_name, partition_name, subpartition_name, indexing
FROM USER_TAB_SUBPARTITIONS
WHERE table_name = 'YOUR_TABLE';
if INDEXING is used on desired subpartitions.
Update
I just see actually this is an overkill because NULL values on column A do not create any index entry anyway. So, it can be simplified to
CREATE TABLE YOUR_TABLE (a INTEGER, b INTEGER, ... more COLUMNS)
PARTITION BY LIST (b) (
PARTITION part_b_1 VALUES (1) INDEXING OFF,
PARTITION part_b_other VALUES (DEFAULT) INDEXING ON
);
For example, if you have index a_b_idx on A, B (in that order):
a) select ... from ... where A = ... will use index
b) select ... from ... where B = ... will not use index
On the other side, if you have index b_a_idx on B, A:
a) select ... from ... where A = ... will not use index
b) select ... from ... where B = ... will use index
Oracle can't use second column in index if it doesn't filter on first column, since in regular cases index is tree-like structure: column1->column2->column3->etc.
You need index on column A only or on columns A, B if you do queries like a).
You need index on column B only or on columns B, A if you do queries like b).
Oracle doesn't store all-null values in index, but it can store null value for A if B contains non-null value.
Sometimes it's more fruitful to read whole table into memory and ignore index. Optimizer can do it if possible result set is big and it goes for all records, since index-to-record transition costs more than simple records read.
Also sometimes it happens erroneously for tables without statistics, so you either need jobs with alter table ... compute statistics or oracle 11+ that can compute statistics like this without jobs.
Most of the times, another index is good thing for queries, but bad thing for updates/disk. Each index takes disk space and each update of record(s) makes updates to every index. So for heavily updated tables it's not good to have many indexes, but for frequently queried tables it's better to have indexes covering all common cases.
For most flat queries (without joins/subqueries/hierarchy) only 1 index is used, so having indexes for each column is generally just a waste of disk space. You need multicolumn index to optimize where A=... and B=...
As for index type, you probably need simple non-unique indexes.
Column A
Let assume that you create an index named _columnA_index_. In general, indexes in RDBMS would not include NULL values, which means there is no index entries in _columnA_index_ pointing to records having NULL values. Thus, the following query
Q1: select * from MyTable where A is null;
will result in a table scan instead ( or DBMS opts to use another index on another column if any)
However, since there is 10% of records having 'different values', the _columnA_index_ will of course help for queries, for example.
Q2: select * from MyTable where A = '123';
In the above example, if the query returns < 1% of the records, the _columnA_index_ is helpful. Depending on how selective the query is, the index greatly improves the performance. You can create an index that is suitable for datatype of column A.
Column B
Similarly, an index on B will not help
Q3: select * from MyTable where B = 1;
but it will help with different values
Q4: select * from MyTable where B = '456';
NULL values
So far, I answered that any index does not help with NULL values. Therefore, if you need to query Q1 most of the time, I suggest the following ideas
Make sure that your version of DBMS does support NULL values be included in indexes. For example Oracle 11g does but not versions before that.
Plan to create function-based index here, again with Oracle. But you can take the idea at least.
Redesign the logic of your application / your need to do querying on Null values. I prefer this approach.