CERN/IT/DB

DB US Visit

Oracle Visit August 20 – 24 2001[ plus related news ]

CERN/IT/DB

Introduction

Oracle Strawman Model

Issues & Concerns

Current Status & Future Directions

AOB

CERN/IT/DB

LHC Datatypes & Oracle

RAW: 1PB/yrESD: ~100TB/yrAOD: ~10TB/yrTAG: ~100GB-1TB/yr

~1 ‘DB’ / month~1 ‘DB’ / year~1 ‘DB’~1 ‘DB’ combined with

AOD• Maybe possible to soften these to ~1 ‘DB’ for all ESD• Would there be a strong advantage?• Different ‘DB’s have different access patterns, access

control, schema, … etc.

CERN/IT/DB

Oracle DeploymentDAQ cluster: current data – no history

export tablespacesto RAW cluster

to/from MSS

ESD cluster: 1/year? 1?

AOD/TAG 1 total?

to RCs to/from RCs

reconstruct ‘shift’ analysis

CERN/IT/DB

RAW

ESD

AOD

TAG

randomseq.

1PB/yr

100TB/yr

10TB/yr

1TB/yr

Data

Users

Tier0

Tier1

CERN/IT/DB

Building Blocks

~100TB “databases” – clusters?

OCCI / OTT

Transportable tablespaces & other techniques for data import / export / exchange

CERN/IT/DB

BT Visit – July 2001

Oracle VLDB site: Enormous Proof of Concept test in 1999 80TB disk, 40TB mirrored, 37TB usable Performed using Oracle 8i, EMC storage “Single instance” – i.e. not cluster

Based on same techniques as identified on paper by IT-DB

Demonstrated > 2 years ago!No concerns for building 100TB today!

CERN/IT/DB

Size of the Largest RDBMS in Commercial Use for DSSSource: Database Scalability Program 2000

Terabytes

3

50

100

1996 2000 2005

Projected By Respondents

CERN/IT/DB

Issues & Concerns

VLDB support

Cluster issues (RAC on Linux etc.)

C++ binding / object model definition

Storage issues

CERN/IT/DB

VLDB Support

RAW DB model revised to active partitions as part of DB (catalog) + offline partitions (not part of DB) + “historical data” (maybe in separate DB?)

Such a strategy is used by many Data Warehouse sites in production today

Does not require any special features But Oracle like suggestion of extending

“resumable statements” to provide “automatic but controlled” access to offline data

CERN/IT/DB

VLDB support cont.

Oracle addressing limits of current architecture Already permits 2EB databases

Limits on e.g. # files, partitions etc are expected to be significantly increased beyond Oracle 9i

An area of work, but not concern…

CERN/IT/DB

Cluster Issues

Real Application Clusters = RAC = significant advance over previous OPS

Should be good fit for HEP read-mostly dataSupported on Linux by COMPAQ, FastTangoNot critical to overall model, but could

simplify deployment significantly e.g. small number of clusters: 1 / data type

COMPAQ Oracle competency centre in Valbonne…

CERN/IT/DB

OCCI / OTT

On-going work with Oracle developers to fix bugs / provide enhancements to meet HEP requirements Fixes prior to start of ß, during ß & post ß

…Currently using HEP data models

More examples welcome…Enhancements via pre-releases, dot

releases and 9i R2

CERN/IT/DB

Storage Issues

Oracle number format provides greater precision than IEEE double

Solutions being investigated to allow efficient storage of floats / doubles / ints without user specifying precision / range

Target: next major Oracle release?

CERN/IT/DB

Side Visits

FNALObjectivityIBMCOMPAQFastTango / NetAppliance

CERN/IT/DB

Summary

Oracle demonstrably interested in continuing to work with HEP on VLDB / LHC issues, both regarding 9i and also future Oracle versions

Strong support from Oracle server group

Strong interest from Oracle Grid team