Partitioning on exisitng table

All,
I wanted to do partition on existing table which does not have any partition before.
My concern is it is a crucial table which is holding millions of records and ofcourse records are being inserted in a regualr basis.
So if i create a new partition on this table , will it cause any datalose or any other impacts.
This is table is having foreign key references too.
Oracle 10g on Solaris 9
Your suggesstions are highly appreciateable..
Thanks in Advance

What version? 10g is a marketing label not a version
SELECT * FROM v$version;What kind of partitioning? RANGE? HASH? LIST? COMPOSITE?
And you can not turn a normal heap table into a partitioned table. You need to create a partitioned table and then do an "exchange."
I would suggest you read the docs and then ask your question after you provide appropriate detail information.
But, as a blanket statement, if you do it properly you can not lose data.

Similar Messages

Partitioning a fact table

I am curious to hear techniques for partitioning a fact table with OWB. I know HOW to setup the partitioning for the table, but what I am curious about is what type of partitioning everyone is suggesting. Take the following example...Lets say we have a sales transaction fact table. It has dimensions of Date, Product, and Store. An immediate partitioning idea is to partition the table by month. But my curiosity arises in the method used to partition the fact table. There is no longer a true date field in the fact table to do range partitioning on. And hash partitioning will not distribute the records by month.
One example I found was to "code" the surrogate key in the date dimension so that it was created in the following manner "YYYYMMDD". Then you could use the range partitioning based on values of the key in the fact table less than 20040200 for Jan. 2004, less than 20040300 for Feb. 2004, and so on.
Is this a good idea?

Jason,
In general, obviously, query performance and scaleability benefit from partitioning. Rather than hitting the entire table upon retrieving data, you would only hit a part of the table. There are two main strategies to identify what partitioning strategy to choose:
1) Users always query specific parts of the data (e.g. data from a particular month) in which case it makes sense for the part to be the size of the partition. If your end users often query by month or compare data on a month-by-month basis, then partitioning by month may well be the right strategy.
2) Improve data loading speed by creating partitions. The database supports partion exchange loading, supported by Warehouse Builder as well, which enables you to swap out a temporary table and a partition at once. In general, your load frequency then decides your partitioning strategy: if you load on a daily basis, perhaps you want daily partions. Beware that for Warehouse Builder to use the partition exchange loading feature you will have to have a date field in the fact table, so you would change the time dimension.
In general, your suggestion for the generated surrogate key would work.
Thanks,
Mark.

Maximum No. of Partitions in a Table?

Hi,
What is the Maximum no.of partitions in a table?
Best Regards,
Naresh Kumar C.

All resides in what is 1K ?
First option (more popular) : 1K=1024, so 1024K = 1024*1024
Second option (less popular) : 1K = 1000, 1024K = 1024*1000
http://en.wikipedia.org/wiki/Byte
Have you really need to 1024K-1 partitions (either one or other option, it's already huge for number of partitions) ? Good luck for maintenance tasks...
Nicolas.

Diagnostic pack, Tuning pack are not in OEM 10g, Add partition to a table

Hi All,
I have 2 questions:
Q.1: In Oracle 9i Oracle Enterprise Manager java console, we had "Diagnostic Pack" and "Tuning Pack" which helped us seeing performance tuning info (session's statistics such as cpu time, pga memory, physical disk reads, etc.) and privded help for sql tuning and performance improvements. But in 10g, the same product (Oracle Enterprise Manager java console) does not include these 2 packs, due to which we are unable to monitor and control performance tuning information/statistics. Now my question is, do we need to install these 2 packs separately in 10g? if yes, where can we get them? (I am sure in 9i, these packages came with OEM console and we didnt need to get them separately)
Q.2: I have a partitioned table having 5 partitions based on range partitioning. Now our requirements have changed and we need to insert values beyong the 5th partition, so we need a 6th partition. Can someone tell me the command to add a new partition to the table? I tried "Alter table xxx add partition yyy ....", but it didn't work. If any one can me the correct syntax, it will be great.
Thanks in advance.

OP is talking about java-based EM, not web-based DBConsole. In fact he/she has to change to DBConsole, because 10g java EM doesn't longer support these tuning features.
Alter table ... partition syntax depends on the kind of partitioning, see the documentation:
http://download.oracle.com/docs/cd/B19306_01/server.102/b14200/statements_3001.htm#i2131048
Werner

Problem in truncate/drop partitions in a table having nested table columns.

Hi,
I have a table that has 2 columns of type nested table. Now in the purge process, when I try to truncate or drop a partition from this table, I get error that I can't do this (because table has nested tables). Can anybody help me telling how I will be able to truncate/drop partition from this table? IF I change column types from nested table to varray type, will it help?
Also, is there any short method of moving existing data from a nested table column to a varray column (having same fields as nested table)?
Thanks in advance.

>
I have a table that has 2 columns of type nested table. Now in the purge process, when I try to truncate or drop a partition from this table, I get error that I can't do this (because table has nested tables). Can anybody help me telling how I will be able to truncate/drop partition from this table?
>
Unfortunately you can't do those operations when a table has a nested table column. No truncate, no drop, no exchange partition at the partition level.
A nested table column is stored as a separate table and acts like a 'child' table with foreign keys to the 'parent' table. It is these 'foreign keys' that prevent the truncation (just like normal foreign keys prevent truncating partions and must be disabled first) but there is no mechanism to 'disable' them.
Just one excellent example (there are many others) of why you should NOT use object columns at all.
>
IF I change column types from nested table to varray type, will it help?
>
Yes but I STRONGLY suggest you take this opportunity to change your data model to a standard relational one and put the 'child' (nested table) data into its own table with a foreign key to the parent. You can create a view on the two tables that can make data appear as if you have a nested table type if you want.
Assuming that you are going to ignore the above advice just create a new VARRAY type and a table with that type as a column. Remember VARRAYs are defined with a maximum size. So the number of nested table records needs to be within the capacity of the VARRAY type for the data to fit.
>
Also, is there any short method of moving existing data from a nested table column to a varray column (having same fields as nested table)?
>
Sure - just CAST the nested table to the VARRAY type. Here is code for a VARRAY type and a new table that shows how to do it.
-- new array type
CREATE OR REPLACE TYPE ARRAY_T AS VARRAY(10) OF VARCHAR2(64)
-- new table using new array type - NOTE there is no nested table storage clause - arrays stored inline
CREATE TABLE partitioned_table_array
     ( ID_ INT,
      arra_col ARRAY_T )
     PARTITION BY RANGE (ID_)
     ( PARTITION p1 VALUES LESS THAN (40)
     , PARTITION p2 VALUES LESS THAN(80)
     , PARTITION p3 VALUES LESS THAN(100)
-- insert the data from the original table converting the nested table data to the varray type
INSERT INTO PARTITIONED_TABLE_ARRAY
SELECT ID_, CAST(NESTED_COL AS ARRAY_T) FROM PARTITIONED_TABLENaturally since there is no more nested table storage you can truncate or drop partitions in the above table
alter table partitioned_table_array truncate partition p1
alter table partitioned_table_array drop partition p1

Table partitioning (intervel partitioning) on existing tables in oracle 11g

Hi i'm newbie to table partitioning. I'm using 11g. I have table of size 32 gb (which has 22 million records) and i want to apply interval partition on that table. I created a empty table with a partition having columns same as source table and take dump of the source table and import into the new partition table. can you please suggest how to import table dump into new table? also is there any other better idea to do the same.

Hi,
imp user/password file=exp.dmp ignore=y
The ignore=y causes the import to skip the table creation and continues to load all rows.
On the other hand, you can insert data into the partitioned table with a subquery from the non-partitioned table such as follows;
insert into patitioned_table
select * from original_table;
Hope it helps,

How to create partition from one table to another?

Hi,
Can any one help me in this :
I have copied table from one schema to another by using the following command. The table is around 300 GB in size and the partitions are not copied. Now i got a request to create partitions in the destination table similar to the source table.
CREATE TABLE user2.table_name AS SELECT * FROM user1.table_name;
I am using Oracle 9i database. This is very urgent, could any one please suggest me how can i create the partitions in user2 table as user1 table.

If you have the TOAD/ SQL DEVELOPER , get the partition DDL from the source table and execute it in the newly created table.
or you can use DBMS_METADATA:
SET LONG 10000
SELECT dbms_metadata.get_ddl('TABLE', 'TEST')
FROM DUAL;
Thanks,
<Moderator Edit - deleted link signature - pl see FAQ link on top right>

Best approach to do Range partitioning on Huge tables.

Hi All,
I am working on 11gR2 oracle 3node RAC database. below are the db details.
SQL> select * from v$version;
BANNER
Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
PL/SQL Release 11.2.0.3.0 - Production
CORE 11.2.0.3.0 Production
TNS for Linux: Version 11.2.0.3.0 - Production
NLSRTL Version 11.2.0.3.0 - Production
in my environment we have 10 big transaction (10 billion rows) tables and it is growing bigger and bigger. Now the management is planning to do a range partition based on created_dt partition key column.
We tested this partitioning startegy with few million record in other environment with below steps.
1. CREATE TABLE TRANSACTION_N
PARTITION BY RANGE ("CREATED_DT")
( PARTITION DATA1 VALUES LESS THAN (TO_DATE(' 2012-08-01 00:00:00', 'YYYY-MM-DD HH24:MI:SS') ) TABLESPACE &&TXN_TAB_PART1,
PARTITIONDATA2 VALUES LESS THAN (TO_DATE(' 2012-09-01 00:00:00', 'YYYY-MM-DD HH24:MI:SS') ) TABLESPACE &&TXN_TAB_PART2,
PARTITION DATA3 VALUES LESS THAN (TO_DATE(' 2012-10-01 00:00:00', 'YYYY-MM-DD HH24:MI:SS') ) TABLESPACE &&TXN_TAB_PART3
as (select * from TRANSACTION where 1=2);
2. exchange partion for data move to new partition table from old one.
ALTER TABLE TRANSACTION_N
EXCHANGE PARTITION DATA1
WITH TABLE TRANSACTION
WITHOUT VALIDATION;
3. create required indexes (took almost 3.5 hrs with parallel 16).
4. Rename the table names and drop the old tables.
this took around 8 hrs for one table which has 70 millions of records, then for billions of records it will take more than 8 hrs. But the problem is we get only 2 to 3 hrs of down time in production to implement these change for all tables.
Can you please suggest the best approach i can do, to copy that much big data from existing table to the newly created partitioned table and create required indexes.
Thanks,
Hari

>
in my environment we have 10 big transaction (10 billion rows) tables and it is growing bigger and bigger. Now the management is planning to do a range partition based on created_dt partition key column.
We tested this partitioning startegy with few million record in other environment with below steps.
1. CREATE TABLE TRANSACTION_N
PARTITION BY RANGE ("CREATED_DT")
( PARTITION DATA1 VALUES LESS THAN (TO_DATE(' 2012-08-01 00:00:00', 'YYYY-MM-DD HH24:MI:SS') ) TABLESPACE &&TXN_TAB_PART1,
PARTITIONDATA2 VALUES LESS THAN (TO_DATE(' 2012-09-01 00:00:00', 'YYYY-MM-DD HH24:MI:SS') ) TABLESPACE &&TXN_TAB_PART2,
PARTITION DATA3 VALUES LESS THAN (TO_DATE(' 2012-10-01 00:00:00', 'YYYY-MM-DD HH24:MI:SS') ) TABLESPACE &&TXN_TAB_PART3
as (select * from TRANSACTION where 1=2);
2. exchange partion for data move to new partition table from old one.
ALTER TABLE TRANSACTION_N
EXCHANGE PARTITION DATA1
WITH TABLE TRANSACTION
WITHOUT VALIDATION;
3. create required indexes (took almost 3.5 hrs with parallel 16).
4. Rename the table names and drop the old tables.
this took around 8 hrs for one table which has 70 millions of records, then for billions of records it will take more than 8 hrs. But the problem is we get only 2 to 3 hrs of down time in production to implement these change for all tables.
Can you please suggest the best approach i can do, to copy that much big data from existing table to the newly created partitioned table and create required indexes.
>
Sorry to tell you but that test and partitioning strategy is essentially useless and won't work for you entire table anyway. One reasone is that if you use the WITHOUT VALIDATION clause you must ensure that the data being exchanged actually belongs to the partition you are putting it in. If it doesn't you won't be able to reenable or rebuild any primary key or unique constraints that exist on the table.
See Exchanging Partitions in the VLDB and Partitioning doc
http://docs.oracle.com/cd/E18283_01/server.112/e16541/part_admin002.htm#i1107555
>
When you specify WITHOUT VALIDATION for the exchange partition operation, this is normally a fast operation because it involves only data dictionary updates. However, if the table or partitioned table involved in the exchange operation has a primary key or unique constraint enabled, then the exchange operation is performed as if WITH VALIDATION were specified to maintain the integrity of the constraints.
If you specify WITHOUT VALIDATION, then you must ensure that the data to be exchanged belongs in the partition you exchange.
>
Comments below are limited to working with ONE table only.
ISSUE #1 - ALL data will have to be moved regardless of the approach used. This should be obvious since your current data is all in one segment but each partition of a partitioned table requires its own segment. So the nut of partitioning is splitting the existing data into multiple segments almost as if you were splitting it up and inserting it into multiple tables, one table for each partition.
ISSUE#2 - You likely cannot move that much data in the 2 to 3 hours window that you have available for down time even if all you had to do was copy the existing datafiles.
ISSUE#3 - Even if you can avoid issue #2 you likely cannot rebuild ALL of the required indexes in whatever remains of the outage windows after moving the data itself.
ISSUE#4 - Unless you have conducted full volume performance testing in another environment prior to doing this in production you are taking on a tremendous amount of risk.
ISSUE#5 - Unless you have fully documented the current, actual execution plans for your most critical queries in your existing system you will have great difficulty overcoming issue #4 since you won't have the requisite plan baseline to know if the new partitioning and indexing strategies are giving you the equivalent, or better, performance.
ISSUE#6 - Things can, and will, go wrong and cause delays no matter which approach you take.
So assuming you plan to take care of issues #4 and #5 you will probably have three viable alternatives:
1. use DBMS_REDEFINITION to do the partitioning on-line. See the Oracle docs and this example from oracle-base for more info.
Redefining Tables Online - http://docs.oracle.com/cd/B28359_01/server.111/b28310/tables007.htm
Partitioning an Existing Table using DBMS_REDEFINITION
http://www.oracle-base.com/articles/misc/partitioning-an-existing-table.php
2. do the partitioning offline and hope that you don't exceed your outage window. Recover by continuing to use the existing table.
3. do the partitioning offline but remove the oldest data to minimize the amount of data that has to be worked with.
You should review all of the tables to see if you can remove older data from the current system. If you can you could use online redefinition that ignores older data. Then afterwards you can extract this old data from the old table for archiving.
If the amount of old data is substantial you can extract the new data to a new partitioned table in parallel and not deal with the old data at all.

Use multiple partitions on a table in query

Hi All,
Overview:-
I have a table - TRACK which is partitioned on weekly basis. Im using this table in one of my SQL queries in which I require to find a monthly count of some column data. The query looks like:-
Select count(*)
from Barcode B
inner join Track partition P(99) T
on B.item_barcode = T.item_barcode
where B.create_date between 20120202 and 20120209;In the above query I am fetching the count for one week using the Partitions created on that table during that week.
Desired output:-
I want to fetch data between 01-Feb and 01-Mar and use the rest of the partitions for that table during the duration in the above query. The weekly partitions currently present for Track table are -
P(99) - 20120202
P(100) - 20120209
P(101) - 20120216
P(102) - 20120223
P(103) - 20120301
My question is that above Ive used one partition successfully, now how can I use the other 4 partitions in the same query if I am finding the count for one month (i.e. from 201201 to 20120301) ?
Environment:-
Oracle version - Oracle 10g R2 (10.2.0.4)
Operating System - AIX version 5
Thanks.
Edited by: Sandyboy036 on Mar 12, 2012 10:47 AM

I'm with damorgan on this one, though I was lazy and only read it twice.
You've got a mix of everything in this one and none of it is correct.
1. If B.create_date is VARCHAR2 this is the wrong way to store dates.
2. All Track partitions are needed for one month if you only have the 5 partitions you listed so there is no point in mentioning any of them by name. So the answer to 'how can I use the other 4 partitions' is - don't; Oracle will use them anyway.
3. BETWEEN 01_Feb and 01-Mar - be aware that the BETWEEN operator includes both endpoints so if you actually used it in your query the data would include March 1.

Partitioning the fact table

Hi Gurus,
I have a question regarding partitioning the cube. When you partition the cube from the Extras menu, will it partition the F table or is it the E table or both.
Second question: After partitioning, how will i know the newly created table names.
Thanks,
ANU

Hi Anu,
Partition Need and its definition
Infocube contains huge amount of data n the table size of the cube increases regularly. so
when a query is executed on cube then it has to check entire table to get the records for
example Sales in Jan08.
Advantage of Partition
so we can partition the cube so that smaller tables are formed .so that report performance
will increase bcoz the query hits that particular partition.
Steps for Partition
1.To partiotion a cube, it must not contain data.
2. Partition can be done using time characteristics 0CALMONTH and fiscalperiod.
steps:
1. in change of the cube, select extras menu and Partioning option.
2. select calmonth time characteristic.
3. it will ask for the time period to partiotion and no. of partiotions. give them
4. activate the cube.
In BI 7 we can partition the cube even if it contains data.
select the cube, right click , select repartitioning.
1. we can delete existing partitions
2. create new ones
3. merge partitions.
Partitioning of the Cube
http://help.sap.com/saphelp_nw04s/helpdata/en/0a/cd6e3a30aac013e10000000a114084/frameset.htm
Partitioning Fields and Values
partition of Infocube
Partitioning of cube using Fiscal period
Infocube Partition
After Partition
You can find the Partition in the following tables in SE11 >
E tables /BIC/E* or /BIC/E(cube name)
Please also go through the following links
Partioning of Cube
partioning
Partioning of ODS object
/thread/733456 [original link is broken]
Hope i had answered your question
Assign points if helpful,
Thanks and regards
Bala

How to create a partition on existing table?

Hey
Could some one please tell me on how to create a partition on existing table?

Could some one please tell me on how to create a partition on existing table?
You can't - that isn't possible. Unless a table is already partitioned you can NOT create another partition on it.
You must either redefine the table as a partitioned table (using the DBMS_REDEFINITION package) or create a new partitioned table and move the data to its new partitions.
The choice will depend on how much data the existing table has and whether you can do it offline.

Partition on MTL_SYSTEM_ITEMS_B table?

Hi,
MTL_SYSTEM_ITEMS_B table has 20 crore rows. Many of the concurrent programs accessing MTL_SYSTEM_ITEMS_B are also taking a very long time to run.
I want to partition MTL_SYSTEM_ITEMS_B. Does oracle have any recommendation on what key to use and the type of partition?
Are there any open issues with partitioning this table?
Thanks

Hi,
See this thread.
Table partitioning on MTL_SYSTEM_ITEMS_B table?
Re: Table partitioning on MTL_SYSTEM_ITEMS_B table?
Thanks,
Hussein

Possible to swap multiple partitions into a table?

Hi,
We are using partition exchnage to swap individual partitions into table which then backed up.
This being done one partition at a time.
Is it possible to swap several partitions of a tabel in one go.
using Oracle 11.2.0.3
partioned by date, one partition of reach day.
Is it possible say to move the last 7 days partitions into the other table for backup using partition exchange?
Thanks

>
We are using partition exchnage to swap individual partitions into table which then backed up.
This being done one partition at a time.
Is it possible to swap several partitions of a tabel in one go.
>
No.
If the goal is to back up the data why not just use expdp to export the data for all seven partitions at once? Then drop the partitions.
If you only use one regular table for the exchange you would have to start with an empty table, swap one partition, backup the table, truncate the table, swap the next partition and so on.
Or you could create a table with seven empty partitions and swap the 7 partitions one at a time and then backup the new partitioned table.
Or you could create seven tables and swap each one with a partition and then backup all seven tables.
Too many choices.

What's the best practice to partition an existing table?

We are using Oracle 11g EE 11.2.0.3.0. We want to partition an existing table. I found some information from this link [http://www.oracle-base.com/articles/misc/partitioning-an-existing-table.php], but I am not sure whether that's the best way. Could anyone share the best practice of partitioning an existing table?
Thanks.
Jun

>
We want to partition a few related tables. A couple of tables have about 30 million rows, and a couple of other tables have about 10 million rows. The data for those tables is for ~2000 accounts, each of them is identified by a column named "account_id". We want to partition the tables by using the "account_id" as the partition key to gain better performance for queries, so we would probably use hash partition. Please advise.
>
1. What evidence do you have that your performance will be any better if you partition those tables?
2. What evidence do you have that there is anything wrong with the performance of your current queries?
3. Have you reviewed the actual execution plans for your most important queries to see if there is even any room for improvement?
If your query uses account_id as a predicate but only pulls a few records from a 'master' table for that key value your performance may actually be worse if you partition that table. That is because using an index range scan Oracle can easily find the ROWIDs of the rows that need to be selected and then easily retrieve them regardless of their physical location.
If you have queries that do NOT use account_id but currently use indexes the performance of those queries may also be worse if you partition that table. Those indexes will be GLOBAL.
There are two major implications when you use hash partitioning:
1. Any query that does NOT include the partitioning key (account_id for your case) will, of necessity, have to use a full table scan if an appropriate index is not available.
2. You will get NO management benefits such as being able to add/remove partitions that include old data.
Before you decide to partition a table you should conduct tests and examine the execution plans for your important queries.

Partitioning an Existing Table with data

Hi All,
I am few tables with data, I need to Partition the table without affecting existing table values is it possible?.
if yes then Please suggest me some ideas to archive that..
Thanks & Regards
Sami

Hi All,
I Need to partition for existing table with 1 million records
1. First partition should be created for 6 months
2.Second partition should created for 1 year.
3.So as of now we have 6 months Data in production + another 6 months data in First partition + another 1 year data in Second partition.
4.More than 2 year’s data’s should be moved other partition or archived.
kindly provide your valuabe suggestion.
Thanks & Regards
Sami

Partitioning on exisitng table

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