Oracle 12c In-memory Database Cache.pdf

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Copyright 2014, Oracle and/or its affiliates. All rights reserved. |

Transform Batch to Real Timewith the Oracle Database

In-Memory 12c Option onOracle Systems

Vince Carbone

Hui DongDavid LutzOracle Performance EngineeringOctober 1, 2014

Oracle ConfidentialInteCopyright 2014, Oracle and/or its affiliates. All rights reserved. |


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Safe Harbor StatementThe following is intended to outline our general product direction. It is inteinformation purposes only, and may not be incorporated into any contract.commitment to deliver any material, code, or functionality, and should notin making purchasing decisions. The development, release, and timing of afunctionality described for Oracles products remains at the sole discretion


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Program Agenda

Configuring the In-Memory Column Store

Populating the In-Memory Column Store

Managing the In-Memory Column Store on RAC

Querying the In-Memory Column Store

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Program Agenda

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Memory Bandwidth Enables Batch to Real-Time

DISK

PCI FLASH

DRAM

12 GB/sec

~1280 GB/sec

58 GB/sec

In-memory deliver

Over 100x more th

Over 14x more thr

What was batch careal time

Oracle SuperCluster T5-8(Full Rack)


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Breakthrough: Dual Format Database

BOTHrow and coformats for same

Simultaneously atransactionally co

Analytics & repor

in-memory Colum

OLTP uses proven

Memory Memory

SALES SALES

RowFormat

ColumnFormat


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SPARC Systems For Maximum In-Memory PerformLarge Memory/High Memory Bandwidth

IM performs complete womemory

Scale-up on

Scale-out on

T4-1 512GBT5-2 1TB

T5-4 2TB

T5-8 4TB

M6-32 32TB

SuperCluster T5-8 and M6-32


9/44Copyright 2014, Oracle and/or its affiliates. All rights reserved. |

System Global Area SGA

Buffer CacheShared Pool Redo Buffer

Large Pool Other shared

Memory Components

In-Memory Area

Configuring : In-Memory Column Store




Controlled by INMparameter

Minimum size of 100

Must be large enougaccommodate both cmeta-data area

SGA_TARGET musenough to accomm

Implemented usinShared Memory (OS

SELECT * FROM V$SGA;

NAME VALUE------------------ ---------Fixed Size 2927176Variable Size 570426808Database Buffers 4634022912Redo Buffers 13848576

In-Memory Area 1024483648



Configuring : In-Memory Column StoreOracle Multitenant with Pluggable Databases

ERP IMPDB1 IMPDB2

Container Database

INMEMORY_SIZE=0G

INMEMORY_SIZE=400G

INMEMORY_SIZE=1600G

INMEMORY_S

Example:

SQL> alter session set contaSQL> alter system set inmeSQL> alter session set contaSQL> alter system set inme


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ERP IMPDB1 IMPDB2

Container Database

INMEMORY_SIZE=0G

INMEMORY_SIZE=1000GINMEMORY_SIZE=1600G

INM

Over subis po

Configuring : In-Memory Column StoreOracle Multitenant with Pluggable Databases


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NewINMEMORY AT

Following segmeneligible

Tables

Partitions

Subpartition

Materialized views

Following segmen

eligible

IOTs

Hash clusters

Out of line LOBs

CREATE TABLE customers

PARTITION BY LIST(PARTITION p1 INMEMORY,(PARTITION p2 NO INMEMORY);

ALTER TABLE sales INMEMORY;

ALTER TABLE salesNO INMEMORY;


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Oracle Compression Advisor And In-Memory

Easy way to deter

memory requirem

Use DBMS_COMPR

Applies MEMCOMP

sample set of data

Returns estimatedcompression ratio


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Program Agenda





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Oracle In-Memory Columnar Technology

Pure in-memory

Not persistent, a

Quick to change

2x to 20x compr

Enabled at table

level

Brings existingdmemory and foroptimized colum

SALES

Pure In-Memory Columnar


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Population is highly scalable

Completed by new sbackground processe

ora_wNNN_orcl

Number of processe

INMEMORY_MAX_POColumn Format

MemoryIMCU IMCU

IMCU IMCU

IMCU IMCU

Populating: In-Memory Column Store


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Each object popu

Column Store is aup of multiple In-Compression Unit

Each IMCU contaientries for a subsethe object

Each column is encompressed indiv


Column Format

MemoryIMCU IMCU

IMCU IMCU

IMCU IMCU


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New INMEMORY

Possible to populacertain columns fr

or partition

Order (not speed)

objects are popula

controlled by PRIO

subclause

Critical, high, me

Defaultnone (

first access)

ALTER TABLE sales INMEMORY;

ALTER TABLE salesNO INMEMORY;

ALTER TABLE sales INMEMORYNO INMEMORY (PROD_ID);

CREATE TABLE orders(c1 number,c2 varchar(20),c3 number)

INMEMORY PRIORITY CRITICALNO INMEMORY (c1);


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Objects compress

population Different levels

FOR DML - Use o

partitions with v

activity

FOR QUERY - Demost tables

FOR CAPACITY -

frequently acces

Great for ILM stra

CREATE TABLE ORDERS

PARTITION BY RANGE (PARTITION p1 INMEMORY NOMEMCOMPRESSPARTITION p2

INMEMORYMEMCOMPRESS FOR DML,PARTITION p3

INMEMORYMEMCOMPRESS FOR QUERY,

:PARTITION p200

INMEMORYMEMCOMPRESS FOR CAPACITY);


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Identifying : Tables With INMEMORY Attribute

NewINMEMORY co

*_TABLES dictionary INMEMORY is a seg

attribute

SELECT table_name, inmemoryFROM USER_TABLES;

TABLE_NAME INMEMORY------------ --------CHANNELS DISABLEDCOSTSCUSTOMERS DISABLED

PRODUCTS ENABLEDSALESTIMES DISABLED

USER_TABLESdoesn

segment attribute

objects Both COSTS & SALES

partitioned => log

INMEMORY attribu

reported in *_TAB_


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Identifying : Tables With INMEMORY Attribute

New view V$IM_SE

Indicate:

Objects populat

Current populat

Can also be used

compression rat

SELECT segment_name name,population_status status

FROM v$IM_SEGMENTS;

NAME STATUS------------ --------PRODUCTS COMPLETEDSALES STARTED


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Identifying : Columns Without the INMEMORY Att


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Program Agenda



DML and the In-Memory Column Store



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IMCUJOURNAL


A journal is usedcolumn store traconsistent

DML operations row store as the

Corresponding ecolumn store ma

Copy of changedin Transaction J

Memory

ColumnFormat


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IMCUJOURNAL


In-Memory Columnever out of date

Read consistency merging contentsthe transaction jo

When number of

journal hits internCU is refreshed

This is an online ocolumns store alw

Memory

ColumnFormat


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Program Agenda





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Scale-Out In-Memory Database to Any Size

Scale-Out across serve

memory and CPUs

In-Memory queries paservers to access local

Scale-out policy is a se(table, partition, sub p


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Scale-Out In-Memory Database to Any Size

Policy is user-spec

Controlled by DISTsubclause

Distribute by rowid rang

Distribute by partition

Distribute AUTO

Parallel Scan Affin

Requires parallel_degre

ALTER TABLE sales INMEMORYDISTRIBUTE BY PARTITION;

ALTER TABLE COSTS INMEMORYDISTRIBUTE AUTO;


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Oracle Database In-Memory: Unique Fault Toleran

Similar to stora

Duplicate in-mecolumns on ano

Enabled per

Application t

In-Memory Colremains availabduplicate after f

Only Available on Engineered Systems


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Oracle Database In-Memory: Unique Fault Toleran

Policy is user-speci

Controlled by DUPL

DUPLICATE

DUPLICATE ALL

ALTER TABLE sales INMEMORYDUPLICATE;

ALTER TABLE COSTS INMEMORYDISTRIBUTE AUTO DUPLICATE ALL;


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Program Agenda





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Why is an In-Memory scan faster than the buffer c

SELECT COL4 FROM MYTABLE;

XXXX

X

RESULT

Row Format

Buffer Cache

Column For

IM Column


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Oracle In-Memory Column Store Storage Index

Each column is t

of multiple colu

Min / max valuefor each columnstorage index

Storage index prpartition pruninperformance for

Memory

SALES

ColumnFormat

Min 1

Max 3

Min 4

Max 7

Min 8Max 12

Min 13

Max 15

Example: Find sales from stores with a store_id of 8 or higher


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Orders of Magnitude Faster Analytic Data Scans

Load

multiplePROMO_IDvalues

Vector

Compareall valuesin 1 cycle

CPU

PROMO_

ID

9999

9999

9999

9999

Example:

Find all salesWith PROMO_ID 9999

VECTO

R

REGIST

ER

Memory

Each CPU core s

memory column

Scans use supervector instructio

Originally de

graphics & sc

Billions of rows/per CPU core

Row format


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Identifying : INMEMORY Table Scan

Optimizer fully a

Cost model adapconsider INMEM

New access metTABLE ACCESS IN ME

Can be disabledparameter

INMEMORY_QUER


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Identifying : INMEMORY Table Scan

NEWSession lev

Best way to deteIn-Memory was

Best way to meabenefits of In-M


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Joining and Combining Data Also Dramatically Fast

Converts joins omultiple tables iscans

Joins tables 10x

Example: Find all orders placed on Christmas eve

LINEORDERDATE_DIM

Da

teKey

Am

ount

Datekey is

24122013

Type=d.d_date='December 24, 2013'

Date

Sum

DateKey


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In-memory Joins

Simple twobetween thDATE_DIM LINEORDER

IM columnadvantage Filter to pr

joins very e

SELECT SUM(lo_extendedprice * lo_discount)revenue

FROM lineorder l,

date_dim d

WHERE l.lo_orderdate = d.d_datekey

AND l.lo_discount BETWEEN 2 AND 3

AND d.d_date='December 24, 2013';


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Creation and Use of Bloom Filter

Bloom filters enable joconverted into fast col

Introduced in Oracle DVery efficiently appliedformat data via SIMD.

Same technique used ton Exadata


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Summary: Oracle Database In-MemoryPowering the Real-Time Enterprise

Extreme Performance& OLTP

Extreme Scale-Out & S

Extreme Availability

Extreme Simplicity

AGILE

EFFICIENT

DATA-

DRIVEN


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