oracle partitioning

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Oracle Partitioning – Yesterday, Today, and TomorrowAnanth RaghavanSenior Development Manager, Oracle Partitioning

The following is intended to outline our general product direction. It is intended for information purposes only, and may not be incorporated into any contract. It is not a commitment to deliver any material, code, or functionality, and should not be relied upon in making purchasing decisions.The development, release, and timing of any features or functionality described for Oracle’s products remain at the sole discretion of Oracle.

Agenda

• History and evolution of Oracle Partitioning• Proven functionality in 7th generation

• Fundamental concepts for success• Resolving some myths• Upcoming new functionality• Q&A

It is• Powerful functionality to logically partition objects into

smaller pieces• Only driven by business requirements• Partitioning for Performance, Manageability, and

Availability

It is not• Just a way to physically divide – or clump - any large

data set into smaller buckets• Enabling pre-requirement to support a specific

hardware/software design • Hash mandatory for shared nothing systems

What is Oracle Partitioning?

Logical Partitioning• Does not underlie any constraints

• SMP, MPP, Cluster, Grid does not matter

• Purely based on the business requirement

• Availability. Manageability, Performance

• Beneficial for every environment• Provides the most comprehensive

functionality

DB

Physical versus Logical PartitioningShared Everything Architecture - Oracle

Physical Partitioning• Fundamental system setup

requirement• Node owns piece of DB

• Enables parallelism• Number of partitions is equivalent to

min. parallelism

• Always needs HASH distribution• Equally sized partitions per node

required for proper load balancing

DB DB DB

Physical versus Logical PartitioningShared Nothing Architecture

• Oracle 8.0• RANGE partitioning• Fundamental Maintenance

operations• Static pruning

• Oracle8i• HASH, composite RANGE-HASH• MERGE partitions• Dynamic pruning• Partition-wise joins

• Oracle9i Release 1• LIST partitioning• Global index maintenance

• Oracle9i Release 2• Fast Split• Composite RANGE-LIST• DEFAULT partition for LIST

• Oracle Database10g Release 1• Internal re-architecture (scalability)• Global hash-partitioned indexes• Local index maintenance

• Oracle Database 10g Release 2• One million partitions• Multi-dimensional pruning• Resource optimized drop table

* Lots of enhancements not shown here, e.g. IOTs, MVs

Oracle PartitioningThe way to Oracle Database 10g Release 2

Core functionality: Partitioning techniques



Partition Maintenance










Performance








Agenda



Oracle PartitioningFundamental Concepts for Success

• While performance seems to be the most visible one, don't forget about the rest, e.g.• Partitioning must address all business-relevant areas of

Performance, Manageability, and Availability

• Partition autonomy is crucial• Fundamental requirement for any partition maintenance

operations• Acknowledge partitions as metadata in the data dictionary

Oracle PartitioningFundamental Concepts for Success

• Provide full partition autonomy• Use local indexes whenever possible• Enable partition all table-level operations for partitions, e.g.

TRUNCATE, MOVE, COMPRESS

• Make partitions visible and usable for database administration• Partition naming for ease of use

• Maintenance operations must be partition-aware• Also true for indexes

• Maintenance operations must not interfere with online usage of a partitioned table

Agenda



Resolving some Myths

“Global Index maintenance is bad”

• Partition maintenance takes longer when global indexes are updated

• Global index maintenance is incremental• No complete rebuild

• Fully transparent• Table and partition are not locked

• Continuous and transparent availability


“Oracle cannot add or remove data from a partitioned table”

• Oracle provides the most comprehensive set of data add and removal operations• DROP removes a partition, including data and metadata• TRUNCATE provides a fast data removal, preserving the

metadata• EXCHANGE provides the capability to exchange a partition

with a standalone table• Preserves data for both sides of the exchange

• Fast data in • Fast data out


“Local indexes are not important and cannot be used as primary or unique index”

• Local indexes are crucial for full partition autonomy• Logical grouping of partition and index segments enables fast

maintenance operations• Only local indexes enable full physical data separation for partitioned

objects

• Local indexes can be unique or primary keys• Inclusion of partitioning key mandatory for local autonomy

• Most indexes are non-unique


“Oracle's Partition creation syntax is worse than the syntax of other vendors”

• No “syntactical sugar’ in SQL for initial object creation• Provided by Enterprise Manager• No metadata extension

• Subpartition templates provide real metadata• Initial creation and future partitions

• It’s getting even better ..• Stay tuned for the upcoming new features section


“ .. Create partitions every month ..”



Agenda

Future Directions (OW 2004/2005 slide)

• Partition techniques enable partitioning for your business• The more techniques the better• Map your business process the most optimal way

• Oracle Database 11g enhances the existing partitioning strategies significantly• Extended composite partitioning strategies• Virtual column based partitioning• Interval Partitioning• REF Partitioning

Extended Partitioning Strategies


Extended Composite Partitioning

• Concept of composite partitioning• Data is partitioned along two dimensions (A,B)• A distinct value pair for the two dimensions uniquely

determines the target partitioning• Composite partitioning is complementary to multi-

column range partitioning• Extensions in Oracle Database 11g

• List-Range • Range-Range• List-Hash• List-List

Extended Composite Partitioning Strategies

Table SALESRANGE(order_date)-RANGE(ship_date)

Jan 2006

... ...

Feb 2006 Mar 2006 Jan 2007

... ...

... ...

...

...

...

...

Jan 2006

Feb 2006

Jan 2007

Composite Partitioning - Concept



Jan 2006

... ...

Feb 2006 Mar 2006 Jan 2007

... ...

... ...

...

...

...

...

Jan 2006

Feb 2006

May 2006

Mar 2006

• All records with order_date in March 2006



Jan 2006

... ...

Feb 2006 Mar 2006 Jan 2007

... ...

... ...

...

...

...

...

Jan 2006

Feb 2006

May 2006

• All records with ship_date in May 2006

May2006



Jan 2006

... ...

Feb 2006 Mar 2006 Jan 2007

... ...

... ...

...

...

...

...

Jan 2006

Feb 2006

May 2006

Mar 2006

• All records with order_date in March 2006 ANDship_date in May 2006

May2006


Virtual Column based Partitioning

Virtual Columns

• Extended Schema attributes are fully derived and dependent on existing common data

• Redundant storage or extended view definitions are solving this problem today• Requires additional maintenance and creates overhead

Business Problem

Solution• Oracle Database 11g introduces virtual columns

• Purely virtual, meta-data only• Treated as real columns except no DML

• Virtual columns can have statistics• Virtual columns are eligible as partitioning key

• Enhanced performance and manageability

Virtual Columns - Example

• Base table with all attributes ...

CREATE TABLE accounts

(acc_no number(10) not null,

acc_name varchar2(50) not null, ...

12500 Adams12507 Blake1266612875 Smith

King


12500 Adams12507 12Blake12666 1212875 12Smith

King

CREATE TABLE accounts (acc_no number(10) not null, acc_name varchar2(50) not null, ... acc_branch number(2) generated always as (to_number(substr(to_char(acc_no),1,2)))

12

• Base table with all attributes ...• ... is extended with the virtual (derived) column


12500 Adams12507 12Blake12666 1212875 12Smith

King

CREATE TABLE accounts (acc_no number(10) not null, acc_name varchar2(50) not null, ... acc_branch number(2) generated always as (to_number(substr(to_char(acc_no),1,2)))partition by list (acc_branch) ...

12

• Base table with all attributes ...• ... is extended with the virtual (derived) column• ... and the virtual column is used as partitioning key

32320 Jones32407 32Clark32758 3232980 32Phillips

32

... Hurd


Interval Partitioning


• Partitioning is key-enabling functionality for managing large volumes of data• One logical object for application transparency• Multiple physical segments for Administration

• Improves Manageability, Availability, and Performance MarJan

Feb

CDRs

SQLSQL

Application

Automate the partition management

BUT• Physical segmentation requires additional data

management overhead• E.g. new partitions must be created on-time for new data


• Interval Partitioning• Extension to Range Partitioning• Full automation for equi-sized range partitions

• Partitions are created as metadata information only• Start Partition is made persistent

• Segments are allocated as soon as new data arrives

• No need to create new partitions• Local indexes are created and maintained as well

No need for any partition management


CREATE TABLE sales (order_date DATE, ...)PARTITON BY RANGE (order_date)INTERVAL(NUMTOYMINTERVAL(1,'month')(PARTITION p_first VALUES LESS THAN ('01-JAN-2006');

Table SALES

Jan 2006

... ...

Feb 2006 Mar 2006 Jan 2007 Oct 2009 Nov 2009

...

First segment is created

• As easy as One, Two, Three ..


Table SALES

Jan 2006

... ...


...

Other partitions only exist in metadata

• As easy as One, Two, Three ..CREATE TABLE sales (order_date DATE, ...)

PARTITON BY RANGE (order_date)

INTERVAL(NUMTOYMINTERVAL(1,'month')

(PARTITION p_first VALUES LESS THAN ('01-JAN-2006');


Table SALES

Jan 2006

... ...


...

INSERT INTO sales (order_date DATE, ...)

VALUES ('04-MAR-2006',...);

New segment is automatically allocated






Table SALES

Jan 2006

... ...


...

INSERT INTO sales (order_date DATE, ...)

VALUES ('17-OCT-2009',...);

... whenever data for a new partition arrives






Table SALES

Jan 2006

... ...


...

• Interval partitioned table can have classical range and automated interval section• Automated new partition management plus full partition

maintenance capabilities: “Best of both worlds”


Table SALES

Jan 2006

... ...


...



1. MERGE and move old partitions for ILM

Range partition section


Table SALES

Jan 2006

... ...


...



1. MERGE and move old partitions for ILM

Range partition section Interval partition section

VALUES ('13-NOV-2009')1. Insert new data• - Automatic segment creation


Table SALES

...

2005 Q1 2006 Oct 2006

• Range partitioned tables can be extended into interval partitioned tables• Simple metadata command• Investment protection

Q2 2006

...


Table SALES

...

2005 Q1 2006 Oct 2006Q2 2006

ALTER TABLE sales (order_date DATE, ...)

SET INTERVAL(NUMTOYMINTERVAL(1,'month');

• Range partitioned tables can be extended into interval partitioned tables• Simple metadata command• Investment protection

...

New monthlyInterval partitions

Old range partition table

...


REF Partitioning

REF Partitioning

• Related tables benefit from same partitioning strategy• Sample order – lineitem

• Redundant storage of the same information solves this problem• Data overhead• Maintenance overhead

Business Problem

Solution• Oracle Database 11g introduces REF Partitioning

• Child table inherits the partitioning strategy of parent table through PK-FK relationship

• Intuitive modelling

• Enhanced Performance and Manageability

Before REF Partitioning

Table ORDERS

Jan 2006

... ...

Feb 2006

Table LINEITEMS

Jan 2006

... ...

Feb 2006

• RANGE(order_date)• Primary key order_id

• RANGE(order_date)• Foreign key order_id

• Redundant storage of order_date• Redundant maintenance

REF Partitioning

Table ORDERS

Jan 2006

... ...

Feb 2006

Table LINEITEMS

Jan 2006

... ...

Feb 2006

• RANGE(order_date)• Primary key order_id

• RANGE(order_date)• Foreign key order_id• RANGE(order_date)• Foreign key order_id

PARTITION BY REFERENCE• Partitioning key inherited through

PK-FK relationship

• Proven functionality in 7th generation• Experience comes with age and customer usage

• Fundamental concepts for success• The most comprehensive and complete offering

• There will be always myths• .. and envious competitors

• Ground-breaking new functionality available soon• 8th generation will be even better

Oracle Partitioning

• Proven functionality in 8th generation• Experience comes with age and customer usage

• Fundamental concepts for success• The most comprehensive and complete offering

• There will be always myths• .. and envious competitors

• Ground-breaking new functionality available soon• 9th generation will be even better

• There is always room for improvements• Any ideas?? Email [email protected]

Oracle Partitioning

The preceding is intended to outline our general product direction. It is intended for information purposes only, and may not be incorporated into any contract. It is not a commitment to deliver any material, code, or functionality, and should not be relied upon in making purchasing decisions.The development, release, and timing of any features or functionality described for Oracle’s products remain at the sole discretion of Oracle.

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Oracle Partitioning

oracle partitioning – yesterday, today, and tomorrow ananth raghavan senior development manager,...

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