Partitioning an already existing table

Hi,
I need to partition many existing tables. All these tables hold more than 50 million data each.
Since i am new to partitioning, can any one kindly guide what are the best practices one should look for under such circumstances.
Is it neccessary to dwell on the following point
1) Type of table (Heap or IOT etc).
2) Indexes and kinds of indexes along with the columns in which they are defined.
3) Block size
4) Constraints
5) Row Chaining, Migration etc.
I have very basic idea about the above mentioned points.
Please guide me as to how should the partitioning be done, what sort of partitioning is best, any performace issues.
I sincerely appreciate the cooperation of all members.
Thanks in advance
Message was edited by:
Master

Hi,
to create a partitioned table from the non portioned table
create table part partition XXXXXXXX
(partition p01 tablespace XX1,
partition p02 tablespace XX2,
partition p03 tablespace XX3,
partition p04 tablespace XX 4
nologging
as select * from old data ;
OR
export the old non partition table data – rename the non partitioned table, create partitioned table import the data
OR
Exchanging Partitions
You can convert a partition (or sub partition) into a non-partitioned table, and a non-partitioned table into a partition (or sub partition) of a partitioned table by exchanging their data segments. You can also convert a hash-partitioned table into a partition of a range-hash partitioned table, or convert the partition of the range-hash partitioned table into a hash-partitioned table. Similarly, you can convert a list-partitioned table into a partition of a range-list partitioned table, or convert the partition of the range-list partitioned table into a list-partitioned table
One of the great features about partitioning, and most specifically range-based partitioning, is the ability to load in new data quickly and easily with minimal impact on the current users. The manuals indicate that the critical command to achieve this is as follows:
alter table pt_tab1 exchange partition p_9999
with table new_data
Ani

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Can we create partitions in an existing table?

Hi,
Can we create partitions in an existing table which has about a million rows? I am using oracle 9i database.
Can any one suggest me on this please.

07b3ea8e-c4c5-4559-9055-ed38853dc64e wrote:
Hi,
Can we create partitions in an existing table which has about a million rows? I am using oracle 9i database.
Can any one suggest me on this please.
can NOT be done.
research DBMS_REDEFINITION

Best way to change partition key on existing table

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Using Oracle 11.20.3 on AIX.
We have a table about 800 million rows and 120gb in size.
Want to try copies oif this table to evalaute different partitiong strategies.
What is the quickest way to do this?
Would have liked say datapump table 1 tro disk and datapumo import the data to new table but do the tables need to be of the same format.
Thanks

>
Using Oracle 11.20.3 on AIX.
We have a table about 800 million rows and 120gb in size.
Want to try copies oif this table to evalaute different partitiong strategies.
What is the quickest way to do this?
Would have liked say datapump table 1 tro disk and datapumo import the data to new table but do the tables need to be of the same format.
>
First your subject asks a different question that the text you posted: Best way to change partition key on existing table. The answer to that question is YOU CAN'T. All data has to be moved to change the partition key since each partition/subpartition is in its own segment. You either create a new table or use DBMS_REDEFINITION to redefine the table online.
Why do you want to export all data to a file first? That just adds to the time and cost of doing the op.
What problem are you trying to use partitioning to solve? Performance? Data maintenance? For performance the appropriate partitioning key and whether to use subpartitions depends on the types of queries and the query predicates you typically use as well as the columns that may be suitable for partition keys.
For maintenance a common method is to partition on a date by year/month/day so you can more easily load new daily/weekly/monthly data into its own partition or drop old data that no longer needs to be kept online.
You should use a small subset of the data when testing your partitionings strategies.
Can you do the partitioning offline in an outage window? If not then using the DBMS_REDEFINITION is your only option.
Without knowing what you are trying to accomplish only general advice can be given. You even mentioned that you might want to use a different set of columns than the curren table has.
A standard heap table uses ONE segment for its data (ignoring possible LOB segments). A partitioned/subpartitioned table uses ONE segment for each partition/subpartition. This means that ALL data must be moved to partition the table (unless you are only creating one partition).
This means that every partitioning scheme that uses a different partition key requires ALL data to be moved again for that test.
Provide some information about what problem you are trying to solve.
>
Is this quicker than datapump?
>
Yes - exporting the data simplying moves it all an additional time. Ok to export if you need a backup before you start.
>
Found artcle which talks about using merge option on datapump import to convert partitioned table to non-partitioned table.
>
How would that apply to you? That isn't what you said you wanted to do.

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hi,
please tell me how to add partition to an existing table.
i have tried
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thanks.

Just Googling for ora-14501 resulted in the following
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Can we addnew partition and sub partition in the existing table in one shor

can we addnew partition and sub partition in the existing table in one short

nav wrote:
can we addnew partition and sub partition in the existing table in one shortYes,
You can and below is the example for Range-List partition
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S.

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Dear All,
My database is 10gR2 and Linux is the operating system.
One of my table in production database is huge and contains lot of data. Table is growing on daily basis. There are many queries that users execute on this table and the criteria of selection is normally entry date of the record, its a field Entrty_Date with date datatype.
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>
total1 wrote:
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