I'm working with an Oracle 11g DB that has an input of 3-5m rows a day. In the future I would like to use partitioning based on the column Timestamp. My goal is to create a new partition for every day, automatically.
I just found ways to create a given range of days i.e. 1-20 but not for a unlimited time (01.01.2014 to mm.dd.yyyy).
For daily ranges you can do it like this:
create table ...
...
interval(numtodsinterval(1, 'DAY'))
(
partition log_data_p1 values less than (to_date('22-04-2015', 'DD-MM-YYYY')),
partition log_data_p2 values less than (to_date('23-04-2015', 'DD-MM-YYYY'))
);
Important to use numtodsinterval instead of numtoyminterval
Oracle 11g does offer automatic partition creation, you just need to create table with proper syntax like this one:
create table
pos_data (
start_date DATE,
store_id NUMBER,
inventory_id NUMBER(6),
qty_sold NUMBER(3)
)
PARTITION BY RANGE (start_date)
INTERVAL(NUMTOYMINTERVAL(1, 'MONTH'))
(
PARTITION pos_data_p2 VALUES LESS THAN (TO_DATE('1-7-2007', 'DD-MM-YYYY')),
PARTITION pos_data_p3 VALUES LESS THAN (TO_DATE('1-8-2007', 'DD-MM-YYYY'))
);
Here, two partitions have been defined and an interval of one month has been specified. If date goes beyond the max date specified in partition then oracle automatically creates new partition.
Similarly you can specify partition for day range and oracle will take care of rest.
Related
I'm creating a database which will utilize composite partitioning. I will partition one table using range partitioning (by date)
and then further subpartition it by hash (by client id). So far so good, no problem, but I also need to have those partitions
stored in separate data files each dbf holding data for a single month. I'm reading on composite partitions and what I found
is that primary range partitioning will be only a logical one and data will be stored in subpartitions instead which seems to
make my goal impossible. Am I right and should look for a different solution?
Thanks in advance.
My databases are Oracle 11g and Oracle 12
On existing table you can move partitions or subpartitions to a different tablespace, i.e. different datafile, examples:
ALTER TABLE scuba_gear MOVE SUBPARTITION bcd_types TABLESPACE tbs23;
ALTER TABLE parts MOVE PARTITION depot2 TABLESPACE ts094;
see Moving Subpartitions and Moving Table Partitions
For new tables typically you would be create them like this:
CREATE TABLE sales
( prod_id NUMBER(6)
, cust_id NUMBER
, time_id DATE
, channel_id CHAR(1)
, promo_id NUMBER(6)
, quantity_sold NUMBER(3)
, amount_sold NUMBER(10,2)
)
PARTITION BY RANGE (time_id)
INTERVAL (NUMTOYMINTERVAL(1,'MONTH'))
STORE IN (ts_1, ts_2, ts_3, ts_4, ts_5, ts_6 ,ts_7 ,ts_8, ts_9, ts_10, ts_11, ts_12)
SUBPARTITION BY HASH (cust_id) SUBPARTITIONS 4
( PARTITION before_2000 VALUES LESS THAN (TO_DATE('01-JAN-2000','dd-MON-yyyy')));
Oracle then will put the monthly partitions by "round-robin" method to these 12 tablespaces. STORE IN clause is also possible for subpartitions, see Creating a composite range-hash partitioned table
I have existing table which has 10 years of data (I have taken dump).
I would like to Range partition the existing table on one date key column within the table.
Most of the examples I see are with CREATE TABLE..PARTITION BY RANGE... to add new partitions. But my table is existing table.
I assume I need some ALTER statement.
ALTER TABLE TABLE_NAME
PARTITION BY RANGE(CREATED_DATE)
PARTITION JAN16 VALUES LESS THAN (01-02-2016),
PARTITION FEB16 VALUES LESS THAN (01-03-2016) AND GREATER THAN(31-01-2016),//OR?
PARTITION MAR16 VALUES BETWEEN (01-03-2016) AND (31-03-2016), //OR?
Two questions..
Do I need Alter statement to add partitioning mechanism or need to work with create statement?
What is the proper syntax for keeping each partition having only ONE MONTH data.
If you are using Oracle 12c Release 2 you could use single ALTER to convert non-partitioned table to partitioned one (this is one way trip):
CREATE TABLE my_tab ( a NUMBER(38,0), b NUMBER(38,0));
ALTER TABLE MY_TAB MODIFY PARTITION BY RANGE (a) INTERVAL (1000) (
PARTITION p1 VALUES LESS THAN (1000)) ONLINE;
You could convert indexes too, adding:
update indexes (index_name [local/global]);
db<>fiddle demo
Beacuse your table non-partitioned you have two options:
Export data, drop table, create new patitioned table, import data.
Use split then exchange partition method. https://oracle-base.com/articles/misc/partitioning-an-existing-table-using-exchange-partition
Also, if you want new partition per month read about SET INTERVAL. For example:
CREATE TABLE tst
(col_date DATE)
PARTITION BY RANGE (col_date) INTERVAL (NUMTOYMINTERVAL(1, 'MONTH'))
(PARTITION col_date_min VALUES LESS THAN (TO_DATE('2010-01-01', 'YYYY-MM-DD')));
Im trying to find on google my situation but no one talk about this situation.
i have a table thats is gonna be partitionized with 2 columns.
for 2 columns partitions can anyone show an example for the interval?
In this case i have only one.
For this example how do i use an interval with 2 columns
INTERVAL( NUMTODSINTERVAL(1,'DAY'))
My table:
create table TABLE_TEST
(
PROCESS_DATE DATE GENERATED ALWAYS AS (TO_DATE(SUBSTR("CHARGE_DATE_TIME",1,10),'yyyymmdd')),
PROCESS_HOUR VARCHAR(10) GENERATED ALWAYS AS (SUBSTR("CHARGE_DATE_TIME",12,2)),
ANUM varchar(100),
SWTICH_DATE_TIME varchar(100),
CHARGE_DATE_TIME varchar(100),
CHARGE varchar(100),
)
TABLESPACE TB_LARGE_TAB
PARTITION BY RANGE (PROCESS_DATE, PROCESS_HOUR)
INTERVAL( NUMTODSINTERVAL(1,'DAY'))
Many Thanks,
Macieira
You can't use an interval if your range has more than one column; you'd get: ORA-14750: Range partitioned table with INTERVAL clause has more than one column. From the documentaion:
You can specify only one partitioning key column, and it must be of NUMBER, DATE, FLOAT, or TIMESTAMP data type.
I'm not sure why you're splitting the date and hour out into separate columns (since a date has a time component anyway), or why you're storing the 'real' date and number values as strings; it would be much simpler to just have columns with the correct data types in the first place. But assuming you are set on storing the data that way and need the separate process_date and process_hour columns as you have them, you can add a third virtual column that combines them:
create table TABLE_TEST
(
PROCESS_DATE DATE GENERATED ALWAYS AS (TO_DATE(SUBSTR(CHARGE_DATE_TIME,1,10),'YYYYMMDD')),
PROCESS_HOUR VARCHAR2(8) GENERATED ALWAYS AS (SUBSTR(CHARGE_DATE_TIME,12,2)),
PROCESS_DATE_HOUR DATE GENERATED ALWAYS AS (TO_DATE(CHARGE_DATE_TIME, 'YYYYMMDDHH24')),
ANUM VARCHAR2(100),
SWTICH_DATE_TIME VARCHAR2(100),
CHARGE_DATE_TIME VARCHAR2(100),
CHARGE VARCHAR2(100)
)
PARTITION BY RANGE (PROCESS_DATE_HOUR)
INTERVAL (NUMTODSINTERVAL(1,'DAY'))
(
PARTITION TEST_PART_0 VALUES LESS THAN (DATE '1970-01-01')
);
Table table_test created.
I've also changed your string data types to varchar2 and added a made-up initial partition. process_hour probably wants to be a number type, depending on how you'll use it. As I don't know why you're choosing your current data types it's hard to tell what would really be more appropriate.
I don't really understand why you'd want the partition range to be hourly and the interval to be one day though, unless you want the partitions to be from, say, midday to midday; in which case the initial partition (test_part_0) would have to specify that time, and your range specification is still wrong for that.
Interval partitioning could be built only on one column.
In your case you have proper partition key column - CHARGE_DATE_TIME. Why do you create virtual columns as VARCHAR2? And why do you need to create partition key on them? Interval partitioning could be built only on NUMBER or DATE columns.
I have a log table with a lot of information.
I would like to partition it into two: first part is the logs from the past month, since they are commonly viewed. Second part is the logs from the rest of the year (Compressed).
My problem is that all the examples of partitions where "up until 1/1/2013", "more recent than 1/1/2013" - That is with fixed dates...
What I am looking for/expecting is a way to define a partition on the last month, so that when the day changes, the logs from 30 days ago, are "automatically" transferred to the compressed partition.
I guess I can create another table which is completley compressed and move info using JOBS, but I was hoping for a built-in solution.
Thank you.
I think you want interval partitions based on a date. This will automatically generate the partitions for you. For example, monthly partitions would be:
create table test_data (
created_date DATE default sysdate not null,
store_id NUMBER,
inventory_id NUMBER,
qty_sold NUMBER
)
PARTITION BY RANGE (created_date)
INTERVAL(NUMTOYMINTERVAL(1, 'MONTH'))
(
PARTITION part_01 values LESS THAN (TO_DATE('20130101','YYYYMMDD'))
)
As data is inserted, Oracle will put into the proper partition or create one if needed. The partition names will be a bit cryptic (SYS_xxxx), but you can use the "partition for" clause to grab only the month you want. For example:
select * from test_data partition for (to_date('20130101', 'YYYYMMDD'))
It is not possible to automatically transfer data to a compressed partition. You can, however, schedule a simple job to compress last month's partition at the beginning of every month with this statement:
ALTER TABLE some_table
MOVE PARTITION FOR (add_months(trunc(SYSDATE), -1)
COMPRESS;
If you wanted to stay with only two partitions: current month and archive for all past transactions you could also merge partitions with ALTER TABLE MERGE PARTITIONS, but as far as I'm concerned it would rebuild the whole archive partition, so I would discourage doing so and stay with storing each month in its separate partition.
Apart from the obvious, can anyone explain the what is different between multicolumn partitioning and using a subpartition? And which one is better for a OLTP scenario? For details, see Managing Partitioned Tables and Indexes in the Oracle Database Administrator's Guide.
A (dumb) example of a table partitioned on multiple columns is:
CREATE TABLE demo1
(
year NUMBER,
month NUMBER,
day NUMBER,
instance NUMBER, /* assuming this can only be 1 or 2 */
other1 VARCHAR2(50),
other2 VARCHAR2(50),
other3 VARCHAR2(50)
)
PARTITION BY RANGE (year,instance)
(
PARTITION data_2009_inst1 VALUES less than (2009,2) TABLESPACE data_2009,
PARTITION data_2009_inst2 VALUES less than (2009,3) TABLESPACE data_2009,
PARTITION data_2010_inst1 VALUES less than (2010,2) TABLESPACE data_2010,
PARTITION data_2010_inst2 VALUES less than (2010,3) TABLESPACE data_2010,
PARTITION data_2011_inst1 VALUES less than (2011,2) TABLESPACE data_2011,
PARTITION data_2011_inst2 VALUES less than (2011,3) TABLESPACE data_2011
);
Similarly, example of a subpartitioned table is:
CREATE TABLE demo2
(
year NUMBER,
month NUMBER,
day NUMBER,
instance NUMBER, /* assuming this can only be 1 or 2 */
other1 VARCHAR2(50),
other2 VARCHAR2(50),
other3 VARCHAR2(50)
)
PARTITION BY RANGE (year)
SUBPARTITION BY LIST (instance) /* Cannot subpartition by range in 10gR2 */
SUBPARTITION template
(
SUBPARTITION i1 VALUES (1),
SUBPARTITION i2 VALUES (2),
SUBPARTITION ix VALUES (DEFAULT)
)
(
PARTITION data_2009 VALUES less than (2010) TABLESPACE data_2009,
PARTITION data_2010 VALUES less than (2011) TABLESPACE data_2010,
PARTITION data_2011 VALUES less than (2012) TABLESPACE data_2011
);
Now what is the difference between these tables? Are they not "logically" the same? I know its far easier to add partitions to demo2 as you need to split partitions on demo1 to get more partitions as time passes by. Which on is better in an OLTP scenario?
On a side note, the reason I am partitioning on the INSTANCE number has to do with Oracle RAC. I am trying to create an "instance affinity" to stop "hot block" from slowing down the database as these need be sent across the interconnect between the RAC nodes. (We have empirically proved that this does make a difference in our testing).
There probably isn't any difference in your case, but in general sub-partitioning allows you to partition in 2 different ways, such as range-hash, range-list. Your sub-partition example is range-list, but equivalent to the single-level range partitioning. However, you could not use a single-level if your sub-partitioning was like this example from the doc you linked:
ALTER TABLE quarterly_regional_sales
ADD PARTITION q1_2000 VALUES LESS THAN (TO_DATE('1-APR-2000','DD-MON-YYYY'))
STORAGE (INITIAL 20K NEXT 20K) TABLESPACE ts3 NOLOGGING
(
SUBPARTITION q1_2000_northwest VALUES ('OR', 'WA'),
SUBPARTITION q1_2000_southwest VALUES ('AZ', 'UT', 'NM'),
SUBPARTITION q1_2000_northeast VALUES ('NY', 'VM', 'NJ'),
SUBPARTITION q1_2000_southeast VALUES ('FL', 'GA'),
SUBPARTITION q1_2000_northcentral VALUES ('SD', 'WI'),
SUBPARTITION q1_2000_southcentral VALUES ('OK', 'TX')
);
One advantage of sub-partitions is that they allow individual fine-grained management of the sub-partitions. For example in a data archive table lets say there are different retention requirements based not only on the date, but another value as well.
Using your example perhaps you are required to keep data with value instance = 1 for 7 years, but data with instance = 2 can be discarded after 4 years. Sub-partitioning would allows you to drop the sub-partitions containing data with instance = 2 independently of the other values.