Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.
Oracle Exadata
Alexandru Tică
DBA Lounge, Iași, April 2016
What is Exadata?
“A wonderful blend of
hardware and software”.
Jonathan Lewis
How does it look like? (part 1)
How does it look like? (part 2)
Source: http://oraclefromguatemala.blogspot.ro/2013/04/los­sabores­y­colores­de­oracle­exa...
How does it look like? (part 3)
The Exadata rack, available at SCC.
Oracle 11.2
3 cell/storage servers
2 DB servers
Eth + ...
Exadata timeline (1)
2008
V1
Exa what? WTF is this?
Exadata timeline (2)
2008
V1
2009
V2
OLTP and DW?
Interesting!
2008
V1
2009
V2
2010
X2
Exadata timeline (3)
Bravo!
2008
V1
2009
V2
2010
X2
2012
X3
Exadata timeline (4)
2013
X4
2008
V1
2009
V2
2010
X2
2012
X3
Exadata timeline (5)
Consolidation, DbaaS, cloud…
What’s the difference?
2013
X4
2015
X5
2008
V1
2009
V2
2010
X2
2012
X3
Exadata timeline (6)
Wasn’t supposed
to be good at
everything?
Money, money, money...
Source: 
http://www.oracle.com/us/products/database/exadata­vs­
ibm­1870172.pdf
Source: http://dbar...
Spot the differences
VS
What’s Wrong on Non-Exadata?
HDD
SAN
NAS
ORACLE Instance IO Sub­system
IO traffic
Optimization?
1. Bigger pipe
2. Less IO ...
Exadata Architecture – The Big Picture
Cell Server 1 Cell Server 2 Cell Server 3
DB Server1 DB Server2
iDB / RDS
Oracle Li...
Exadata Magic
Smart Scan HCC
Smart Flash Cache
IO Resource Manger
DEMO 1 - Magic Switch: ON/OFF
640mil rows
Magic OFF
Magic ON
select count(*) from vanzari
where valoare < 100;
cell_offloa...
Smart Scan Magic
DB Node
Cell Node 1 Cell Node 2 Cell Node 3
select sum(valoare)
from vanzari where
tara = ‘RO’;
ASM
IDB p...
Column Projection
● Instead of returning whole Oracle blocks, the storage layer
will pump in just the needed column values...
DEMO: Column projection
Predicate Filtering
● Instead of pushing full Oracle blocks from the storage to the
Oracle instance, only those records ma...
Storage Indexes Explained
VANZARI
table
1MB 1MB
1MB1MB1MB1MB1MB1MB 1MB
1MB1MB1MB1MB1MB
1MB 1MB 1MB1MB1MB1MB1MB
min max min...
DEMO: Storage Indexes
Do You Want to Drop all DB Indexes?
Think twice!
● There are many scenarios where SI can’t be used (e.g.
get the MIN or MA...
Smart Flash Scan
4 cards x 4 disks x
24GB = 384GB on
every storage cell
Controlling the SFC
CELL_FLASH_CACHE
NONE
DEFAULT
KEEP
on segment level
DB Developer
Friendly Side
DBA 
Admin
Ugly Side
ce...
DEMO: Smart Flash Cache
HCC: Hybrid Columnar Compression
Compression
Type
Description Expected
Ratio
QUERY LOW LZA compression algorithm. Low CPU
...
HCC Pitfalls
● Only tables can be compressed. Indexes are not included.
● Exadata inter-operability only. Pay attention wh...
HCC Demo
IO Resource Manager
● Tight integration with Database Resource Manager
● Provides IO prioritization
● Can be enforced acro...
IORM Architecture
IORM Demo
● Smart file creation
● Improved RMAN Incremental Backups
● Improved RMAN restores
● Flash cache compression (from 11.2.3....
Things I don’t Like
● The Exadata official documentation was not public
accessible. It’s fixed now via a patch: Patch 1038...
Q & A
Upcoming SlideShare
Loading in …5
×

Exadata

1,269 views

Published on

An introduction to Oracle Exadata.

Published in: Education
  • Be the first to comment

  • Be the first to like this

Exadata

  1. 1. Oracle Exadata Alexandru Tică DBA Lounge, Iași, April 2016
  2. 2. What is Exadata? “A wonderful blend of hardware and software”. Jonathan Lewis
  3. 3. How does it look like? (part 1)
  4. 4. How does it look like? (part 2) Source: http://oraclefromguatemala.blogspot.ro/2013/04/los­sabores­y­colores­de­oracle­exadata.html S S S S DB DB DB DB X2­8 Full  Rack
  5. 5. How does it look like? (part 3) The Exadata rack, available at SCC. Oracle 11.2 3 cell/storage servers 2 DB servers Eth + IB switches  + KVM Just a quarter RAC!
  6. 6. Exadata timeline (1) 2008 V1 Exa what? WTF is this?
  7. 7. Exadata timeline (2) 2008 V1 2009 V2 OLTP and DW? Interesting!
  8. 8. 2008 V1 2009 V2 2010 X2 Exadata timeline (3) Bravo!
  9. 9. 2008 V1 2009 V2 2010 X2 2012 X3 Exadata timeline (4)
  10. 10. 2013 X4 2008 V1 2009 V2 2010 X2 2012 X3 Exadata timeline (5) Consolidation, DbaaS, cloud… What’s the difference?
  11. 11. 2013 X4 2015 X5 2008 V1 2009 V2 2010 X2 2012 X3 Exadata timeline (6) Wasn’t supposed to be good at everything?
  12. 12. Money, money, money... Source:  http://www.oracle.com/us/products/database/exadata­vs­ ibm­1870172.pdf Source: http://dbareactions.com/post/51674494263/when­we­ went­shopping­for­oracle­licensing
  13. 13. Spot the differences VS
  14. 14. What’s Wrong on Non-Exadata? HDD SAN NAS ORACLE Instance IO Sub­system IO traffic Optimization? 1. Bigger pipe 2. Less IO traffic
  15. 15. Exadata Architecture – The Big Picture Cell Server 1 Cell Server 2 Cell Server 3 DB Server1 DB Server2 iDB / RDS Oracle Linux Oracle 11.2 ASM Oracle Linux cellsrv DB side Storage side
  16. 16. Exadata Magic Smart Scan HCC Smart Flash Cache IO Resource Manger
  17. 17. DEMO 1 - Magic Switch: ON/OFF 640mil rows Magic OFF Magic ON select count(*) from vanzari where valoare < 100; cell_offload_processing ~10x faster
  18. 18. Smart Scan Magic DB Node Cell Node 1 Cell Node 2 Cell Node 3 select sum(valoare) from vanzari where tara = ‘RO’; ASM IDB protocol Get blocks from VANZARI Info about the query. Direct path read? Column projection Predicate filtering Storage indexes Filtereddata
  19. 19. Column Projection ● Instead of returning whole Oracle blocks, the storage layer will pump in just the needed column values. ● The IO traffic is reduced. ● For JOINs, besides columns from the SELECT list, the ones from the join are also transferred. YES, “SELECT *” when just some columns are  needed isn’t a good idea on Exadata too! 
  20. 20. DEMO: Column projection
  21. 21. Predicate Filtering ● Instead of pushing full Oracle blocks from the storage to the Oracle instance, only those records matching the predicate will be pumped in to the wire. ● The IO traffic is reduced (the filtering is done on the storage side) ● Does work for joins too using bloom filters, but on the storge servers.
  22. 22. Storage Indexes Explained VANZARI table 1MB 1MB 1MB1MB1MB1MB1MB1MB 1MB 1MB1MB1MB1MB1MB 1MB 1MB 1MB1MB1MB1MB1MB min max min max Storage 1 Storage 2 Storage 3 select count(*) from vanzari where vanzari <= 1000; Perfect for: =, <, >, BETWEEN, <=, >=, IN, IS NULL, IS NOT NULL
  23. 23. DEMO: Storage Indexes
  24. 24. Do You Want to Drop all DB Indexes? Think twice! ● There are many scenarios where SI can’t be used (e.g. get the MIN or MAX for a column) ● SI is a transient in-memory structure. Restart a storage server and you lost all storage indexes on that server ● The decision to create a SI is fully automated and it depends on the workload. ● A SI can’t be used to enforce a PK constraint ● SI are limited to only 8 columns/table ● No integration between SI and CBO ● There’s no such thing as functional SI. ● A SI can’t be used for FK columns to avoid locking issues
  25. 25. Smart Flash Scan 4 cards x 4 disks x 24GB = 384GB on every storage cell
  26. 26. Controlling the SFC CELL_FLASH_CACHE NONE DEFAULT KEEP on segment level DB Developer Friendly Side DBA  Admin Ugly Side cellcli on storage level CREATE  FLASHCACHE ALTER CELL  DROP  FLASHCACHE
  27. 27. DEMO: Smart Flash Cache
  28. 28. HCC: Hybrid Columnar Compression Compression Type Description Expected Ratio QUERY LOW LZA compression algorithm. Low CPU and low compression. 4x QUERY HIGH ZLIB (gzip) compression. 6x ARCHIVE LOW ZLIB (gzip) but with a higher compression level. 7x ARCHIVE HIGH BZIP2 compression. CPU intensive, high compression rate. 12x
  29. 29. HCC Pitfalls ● Only tables can be compressed. Indexes are not included. ● Exadata inter-operability only. Pay attention when restoring HCC data on a non-exadata machine.. ● Not good for OLTP. ● May consume a lot of CPU (for compression, but for de- compression too). ● It’s not a true columnar model, so wasn’t really designed having the performance idea in mind
  30. 30. HCC Demo
  31. 31. IO Resource Manager ● Tight integration with Database Resource Manager ● Provides IO prioritization ● Can be enforced across different databases hosted on the same Exadata machine ● A very important component for consolidated/shared architectures ● In old versions of Exadata, only physical disks were managed by IORM. Flash disks were not handled by IORM. However, this is not true starting with 11.2.3.3.0. ● Workload optimization: low_latency, high_throughput, balanced, auto
  32. 32. IORM Architecture
  33. 33. IORM Demo
  34. 34. ● Smart file creation ● Improved RMAN Incremental Backups ● Improved RMAN restores ● Flash cache compression (from 11.2.3.3.0) ● Automatic HDD scrubbing and repair Other Exadata Goodies
  35. 35. Things I don’t Like ● The Exadata official documentation was not public accessible. It’s fixed now via a patch: Patch 10386736: Storage Application for the Grid Environment 11.2.3.2.0 for Linux x86-64 - DOCUMENTATION FOR EXADATA 11.2 ● It’s a closed engineered product. However, according to Kevin Closson, Exadata was originally intended to be an open hardware stack. ● The lack of good integration of CBO with Exadata storage (Bug 10248538: OPTIMIZER COST MODEL NOT EXADATA- AWARE) ● Big room for performance instability (storage indexes, flash cache, direct path read etc.) ● The huge price
  36. 36. Q & A

×