This document discusses tuning SQL on Oracle Exadata. It makes three main points:
1. Gathering and displaying execution plan data differs slightly on Exadata compared to non-Exadata databases.
2. The general approach to optimization is similar to non-Exadata, focusing on features like smart scans, storage indexes, and parallelism that provide the most benefit.
3. Rewriting SQL queries can have a dramatic impact on performance by enabling offloading and reducing disk I/O, with examples showing savings of over 98% in run time.
Troubleshooting Complex Performance issues - Oracle SEG$ contentionTanel Poder
From Tanel Poder's Troubleshooting Complex Performance Issues series - an example of Oracle SEG$ internal segment contention due to some direct path insert activity.
"It can always get worse!" – Lessons Learned in over 20 years working with Or...Markus Michalewicz
First presented during the DOAG 2022 Conference and Exhibition, this presentation discusses and reviews the most significant lessons learned in over 20 years of working with Oracle Maximum Availability Architecture. It explains why documentation is good, but automated checks are better, and why standardization can help increase the availability of nearly all systems, including database systems.
Troubleshooting Complex Performance issues - Oracle SEG$ contentionTanel Poder
From Tanel Poder's Troubleshooting Complex Performance Issues series - an example of Oracle SEG$ internal segment contention due to some direct path insert activity.
"It can always get worse!" – Lessons Learned in over 20 years working with Or...Markus Michalewicz
First presented during the DOAG 2022 Conference and Exhibition, this presentation discusses and reviews the most significant lessons learned in over 20 years of working with Oracle Maximum Availability Architecture. It explains why documentation is good, but automated checks are better, and why standardization can help increase the availability of nearly all systems, including database systems.
Tanel Poder - Performance stories from Exadata MigrationsTanel Poder
Tanel Poder has been involved in a number of Exadata migration projects since its introduction, mostly in the area of performance ensurance, troubleshooting and capacity planning.
These slides, originally presented at UKOUG in 2010, cover some of the most interesting challenges, surprises and lessons learnt from planning and executing large Oracle database migrations to Exadata v2 platform.
This material is not just repeating the marketing material or Oracle's official whitepapers.
This is the presentation on ASH that I did with Graham Wood at RMOUG 2014 and that represents the final best effort to capture essential and advanced ASH content as started in a presentation Uri Shaft and I gave at a small conference in Denmark sometime in 2012 perhaps. The presentation is also available publicly through the RMOUG website, so I felt at liberty to post it myself here. If it disappears it would likely be because I have been asked to remove it by Oracle.
Oracle RAC 12c Practical Performance Management and Tuning as presented during Oracle Open World 2013 with Michael Zoll.
This is part three of the Oracle RAC 12c "reindeer series" used for OOW13 Oracle RAC-related presentations.
This part concludes the main part of the "reindeer series" except for one bonus track "Oracle Multitenant meets Oracle RAC 12c" (available via SlidesShare, too).
Oracle Database Performance Tuning Advanced Features and Best Practices for DBAsZohar Elkayam
Oracle Week 2017 slides.
Agenda:
Basics: How and What To Tune?
Using the Automatic Workload Repository (AWR)
Using AWR-Based Tools: ASH, ADDM
Real-Time Database Operation Monitoring (12c)
Identifying Problem SQL Statements
Using SQL Performance Analyzer
Tuning Memory (SGA and PGA)
Parallel Execution and Compression
Oracle Database 12c Performance New Features
Any DBA from beginner to advanced level, who wants to fill in some gaps in his/her knowledge about Performance Tuning on an Oracle Database, will benefit from this workshop.
The biggest headine at the 2009 Oracle OpenWorld was when Larry Ellison announced that Oracle was entering the hardware business with a pre-built database machine, engineered by Oracle. Since then businesses around the world have started to use these engineered systems. This beginner/intermediate-level session will take you through my first 100 days of starting to administer an Exadata machine and all the roadblocks and all the success I had along this new path.
It is no secret that for high-performance ETL processes, not only queries but also write operations should be parallelized.
But when you make use of it, is it simply "switch on and forget"? What do you have to consider? Can it also have negative effects?
After a short reminder on how it works (including space management methods), some patterns are presented that have been noticed in several ETL review and tuning projects and help to find the answers to the following questions:
What is the interaction between PDML and partitioning of the target table? Can PDML lead to increased fragmentation of the tablespace? Can you control it? How does the Hint PQ_DISTRIBUTE help? Do indexes on the target table have any influence?
This is a recording of my Advanced Oracle Troubleshooting seminar preparation session - where I showed how I set up my command line environment and some of the main performance scripts I use!
Tanel Poder - Performance stories from Exadata MigrationsTanel Poder
Tanel Poder has been involved in a number of Exadata migration projects since its introduction, mostly in the area of performance ensurance, troubleshooting and capacity planning.
These slides, originally presented at UKOUG in 2010, cover some of the most interesting challenges, surprises and lessons learnt from planning and executing large Oracle database migrations to Exadata v2 platform.
This material is not just repeating the marketing material or Oracle's official whitepapers.
This is the presentation on ASH that I did with Graham Wood at RMOUG 2014 and that represents the final best effort to capture essential and advanced ASH content as started in a presentation Uri Shaft and I gave at a small conference in Denmark sometime in 2012 perhaps. The presentation is also available publicly through the RMOUG website, so I felt at liberty to post it myself here. If it disappears it would likely be because I have been asked to remove it by Oracle.
Oracle RAC 12c Practical Performance Management and Tuning as presented during Oracle Open World 2013 with Michael Zoll.
This is part three of the Oracle RAC 12c "reindeer series" used for OOW13 Oracle RAC-related presentations.
This part concludes the main part of the "reindeer series" except for one bonus track "Oracle Multitenant meets Oracle RAC 12c" (available via SlidesShare, too).
Oracle Database Performance Tuning Advanced Features and Best Practices for DBAsZohar Elkayam
Oracle Week 2017 slides.
Agenda:
Basics: How and What To Tune?
Using the Automatic Workload Repository (AWR)
Using AWR-Based Tools: ASH, ADDM
Real-Time Database Operation Monitoring (12c)
Identifying Problem SQL Statements
Using SQL Performance Analyzer
Tuning Memory (SGA and PGA)
Parallel Execution and Compression
Oracle Database 12c Performance New Features
Any DBA from beginner to advanced level, who wants to fill in some gaps in his/her knowledge about Performance Tuning on an Oracle Database, will benefit from this workshop.
The biggest headine at the 2009 Oracle OpenWorld was when Larry Ellison announced that Oracle was entering the hardware business with a pre-built database machine, engineered by Oracle. Since then businesses around the world have started to use these engineered systems. This beginner/intermediate-level session will take you through my first 100 days of starting to administer an Exadata machine and all the roadblocks and all the success I had along this new path.
It is no secret that for high-performance ETL processes, not only queries but also write operations should be parallelized.
But when you make use of it, is it simply "switch on and forget"? What do you have to consider? Can it also have negative effects?
After a short reminder on how it works (including space management methods), some patterns are presented that have been noticed in several ETL review and tuning projects and help to find the answers to the following questions:
What is the interaction between PDML and partitioning of the target table? Can PDML lead to increased fragmentation of the tablespace? Can you control it? How does the Hint PQ_DISTRIBUTE help? Do indexes on the target table have any influence?
This is a recording of my Advanced Oracle Troubleshooting seminar preparation session - where I showed how I set up my command line environment and some of the main performance scripts I use!
Oracle SQL Developer Top 10 Tips & TricksJeff Smith
Oracle SQL Developer product manager Jeff Smith shares his top 10 tips for boosting productivity and saving time while working with the Oracle Database IDE.
Fast and Furious: Handling Edge Computing Data With Oracle 19c Fast Ingest an...Jim Czuprynski
The Internet of Things (IoT) has deep use cases - energy grids, communications, policing, security, and manufacturing. I’ll show how to use Oracle 19c’s Fast Ingest and Fast Lookup features to load IoT data from “edge” sources to take immediate advantage of that information in nearly real time.
MySQL Cluster 7.3 Performance Tuning - Severalnines SlidesSeveralnines
The MySQL Cluster 7.x series introduced a number of features to allow for fine-grained control over the real-time behaviour of the NDB storage engine. New threads have been introduced, and users are able to control placement of these threads, as well as locking the memory such that no swapping occurs. In an ideal run-time environment, CPUs handling data node threads will not execute other threads apart from OS kernel threads or interrupt handling. Correct tuning of certain parameters can be specially important for certain types of workloads.
This presentation covers the different tuning aspects of MySQL Cluster.
- Application design guidelines
- Schema Optimization
- Index Selection and Tuning
- Query Tuning
- OS Tuning
- Data Node internals
- Optimizations for real-time behaviour
This presentation looks closely at how to get the most out of your MySQL Cluster 7.x runtime environment.
Breakthrough performance with MySQL Cluster (2012)Frazer Clement
Presentation from the MySQL Connect conference in San Francisco 2012.
Describes cluster architecture and impacts on performance, benchmarking, analysing and techniques for improving performance.
MySQL Without the SQL -- Oh My! Longhorn PHP ConferenceDave Stokes
You can now use MySQL without needing to know Structured Query Language (SQL) with the MySQL Document Store. Access JSON documents and/or relational tables using the new X DevAPI
Using SQL Plan Management (SPM) to Balance Plan Flexibility and Plan StabilityEnkitec
This presentation is about understanding all 3 components of SPM and how we can use this technology to efficiently migrate "good" Execution Plans from one Release to another, or from one System to another.
"Impact of front-end architecture on development cost", Viktor TurskyiFwdays
I have heard many times that architecture is not important for the front-end. Also, many times I have seen how developers implement features on the front-end just following the standard rules for a framework and think that this is enough to successfully launch the project, and then the project fails. How to prevent this and what approach to choose? I have launched dozens of complex projects and during the talk we will analyze which approaches have worked for me and which have not.
Epistemic Interaction - tuning interfaces to provide information for AI supportAlan Dix
Paper presented at SYNERGY workshop at AVI 2024, Genoa, Italy. 3rd June 2024
https://alandix.com/academic/papers/synergy2024-epistemic/
As machine learning integrates deeper into human-computer interactions, the concept of epistemic interaction emerges, aiming to refine these interactions to enhance system adaptability. This approach encourages minor, intentional adjustments in user behaviour to enrich the data available for system learning. This paper introduces epistemic interaction within the context of human-system communication, illustrating how deliberate interaction design can improve system understanding and adaptation. Through concrete examples, we demonstrate the potential of epistemic interaction to significantly advance human-computer interaction by leveraging intuitive human communication strategies to inform system design and functionality, offering a novel pathway for enriching user-system engagements.
GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...James Anderson
Effective Application Security in Software Delivery lifecycle using Deployment Firewall and DBOM
The modern software delivery process (or the CI/CD process) includes many tools, distributed teams, open-source code, and cloud platforms. Constant focus on speed to release software to market, along with the traditional slow and manual security checks has caused gaps in continuous security as an important piece in the software supply chain. Today organizations feel more susceptible to external and internal cyber threats due to the vast attack surface in their applications supply chain and the lack of end-to-end governance and risk management.
The software team must secure its software delivery process to avoid vulnerability and security breaches. This needs to be achieved with existing tool chains and without extensive rework of the delivery processes. This talk will present strategies and techniques for providing visibility into the true risk of the existing vulnerabilities, preventing the introduction of security issues in the software, resolving vulnerabilities in production environments quickly, and capturing the deployment bill of materials (DBOM).
Speakers:
Bob Boule
Robert Boule is a technology enthusiast with PASSION for technology and making things work along with a knack for helping others understand how things work. He comes with around 20 years of solution engineering experience in application security, software continuous delivery, and SaaS platforms. He is known for his dynamic presentations in CI/CD and application security integrated in software delivery lifecycle.
Gopinath Rebala
Gopinath Rebala is the CTO of OpsMx, where he has overall responsibility for the machine learning and data processing architectures for Secure Software Delivery. Gopi also has a strong connection with our customers, leading design and architecture for strategic implementations. Gopi is a frequent speaker and well-known leader in continuous delivery and integrating security into software delivery.
Software Delivery At the Speed of AI: Inflectra Invests In AI-Powered QualityInflectra
In this insightful webinar, Inflectra explores how artificial intelligence (AI) is transforming software development and testing. Discover how AI-powered tools are revolutionizing every stage of the software development lifecycle (SDLC), from design and prototyping to testing, deployment, and monitoring.
Learn about:
• The Future of Testing: How AI is shifting testing towards verification, analysis, and higher-level skills, while reducing repetitive tasks.
• Test Automation: How AI-powered test case generation, optimization, and self-healing tests are making testing more efficient and effective.
• Visual Testing: Explore the emerging capabilities of AI in visual testing and how it's set to revolutionize UI verification.
• Inflectra's AI Solutions: See demonstrations of Inflectra's cutting-edge AI tools like the ChatGPT plugin and Azure Open AI platform, designed to streamline your testing process.
Whether you're a developer, tester, or QA professional, this webinar will give you valuable insights into how AI is shaping the future of software delivery.
Let's dive deeper into the world of ODC! Ricardo Alves (OutSystems) will join us to tell all about the new Data Fabric. After that, Sezen de Bruijn (OutSystems) will get into the details on how to best design a sturdy architecture within ODC.
Key Trends Shaping the Future of Infrastructure.pdfCheryl Hung
Keynote at DIGIT West Expo, Glasgow on 29 May 2024.
Cheryl Hung, ochery.com
Sr Director, Infrastructure Ecosystem, Arm.
The key trends across hardware, cloud and open-source; exploring how these areas are likely to mature and develop over the short and long-term, and then considering how organisations can position themselves to adapt and thrive.
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
Expansion of bot farms – how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks – Europe
Systemic attacks in the Middle East
Download the full report from here:
https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
Builder.ai Founder Sachin Dev Duggal's Strategic Approach to Create an Innova...Ramesh Iyer
In today's fast-changing business world, Companies that adapt and embrace new ideas often need help to keep up with the competition. However, fostering a culture of innovation takes much work. It takes vision, leadership and willingness to take risks in the right proportion. Sachin Dev Duggal, co-founder of Builder.ai, has perfected the art of this balance, creating a company culture where creativity and growth are nurtured at each stage.
Search and Society: Reimagining Information Access for Radical FuturesBhaskar Mitra
The field of Information retrieval (IR) is currently undergoing a transformative shift, at least partly due to the emerging applications of generative AI to information access. In this talk, we will deliberate on the sociotechnical implications of generative AI for information access. We will argue that there is both a critical necessity and an exciting opportunity for the IR community to re-center our research agendas on societal needs while dismantling the artificial separation between the work on fairness, accountability, transparency, and ethics in IR and the rest of IR research. Instead of adopting a reactionary strategy of trying to mitigate potential social harms from emerging technologies, the community should aim to proactively set the research agenda for the kinds of systems we should build inspired by diverse explicitly stated sociotechnical imaginaries. The sociotechnical imaginaries that underpin the design and development of information access technologies needs to be explicitly articulated, and we need to develop theories of change in context of these diverse perspectives. Our guiding future imaginaries must be informed by other academic fields, such as democratic theory and critical theory, and should be co-developed with social science scholars, legal scholars, civil rights and social justice activists, and artists, among others.
16. How
to
Generate
select DBMS_SQLTUNE.REPORT_SQL_MONITOR(
sql_id=>'&sql_id',
session_id=>nvl('&sid',sys_context('userenv','sid')),
type=>'&report_type',
report_level=>'ALL') as report
from dual;
select *
from table(DBMS_XPLAN.DISPLAY_CURSOR(
'&sql_id','&child_no',
nvl('&format','ALLSTATS LAST')));
Defaults
to
last
statement
executed
in
the
current
session
16
23. The
Good
• Smart
scans
• Storage
indexes
• ESFC
• Parallelism
• ParJJoning
Features
where
you
get
the
most
bang
for
your
SQL
tuning
buck.
23
24. Smart
Scans
• Goal
is
to
reduce
the
amount
of
data
sent
from
storage
nodes
to
database
nodes
• Only
happen
when
– Full
scan
(either
TABLE
or
INDEX
FAST
FULL)
– Direct
path
reads
• Blocks
(rows)
returned
to
PGA
(not
to
buffer
cache)
– Results
limited
via
Column
ProjecJon,
Predicate
Filtering,
Join
filters
(bloom)
24
25. How
do
you
know?
• V$SQL
family
of
views:
– IO_CELL_OFFLOAD_RETURNED_BYTES
– IO_CELL_OFFLOAD_ELIGIBLE_BYTES
• Wait
event
(+)
– cell
smart
table
scan
– cell
smart
index
scan
• Plan
Does
not
necessarily
– TABLE
ACCESS
STORAGE
FULL
mean
a
smart
scan
occurred
but
that
it
– Storage()
predicate
could!
25
27. Storage
Indexes
• Goal
is
to
eliminate
disk
I/O
• Built
automaJcally
(max
8
columns
per
table)
• Store
min
and
max
column
values
– Storage
units
which
cannot
contain
requested
rows
are
skipped
• Requires
– Smart
scan
– WHERE
clause
with
at
least
1
predicate
– Simple
comparison
operator
(=,<,>,etc.)
27
28. How
do
you
know?
Check
session
stats
(v$mystat)
for
'cell
physical
IO
bytes
saved
by
storage
index'
SQL> select s.name, m.value cell_stats
2 from v$mystat m, v$statname s
3 where s.statistic# = m.statistic#
4 and name like ('%storage%')
5 /
NAME CELL_STATS
--------------------------------------------- -----------------
cell physical IO bytes saved by storage index 9,571,704,832
CumulaJve
for
session
28
29. Exadata
Smart
Flash
Cache
(ESFC)
• A
disk
cache
for
the
storage
servers
• Usage
is
mostly
automaJc
– Can
pin
tables
using
STORAGE (CELL_FLASH_CACHE KEEP)
• Helps
with
OLTP
workloads
• Reads
from
storage
servers
done
with
async
calls
to
both
ESFC
and
disk
– Winner
returns
data
• Smart
scans
may
use
ESFC
if
table
is
pinned
29
30. How
do
you
know?
Check
session
stats
(v$mystat)
for
'cell
flash
cache
read
hits'
SQL> select s.name, m.value hits
2 from v$mystat m, v$statname s
3 where s.statistic# = m.statistic#
4 and name like ('cell flash%')
5 /
NAME HITS
--------------------------------------------- -----------
cell flash cache read hits 5,424,023
30
31. Of
course,
there
are
also
big
wins
to
be
gained
with
parallelism
and
parJJoning.
31
32. What
happens
when…
SQL
PX?
Part?
Hints?
Offload?
LIO
Time
Original
No
No
No
No
2085k
6.1
min
Original
No
Yes
No
Yes
1503k
27.32
sec
Original
No
Yes
Yes
(HJ)
Yes
127k
15.76
sec
Original
Yes
Yes
No
Yes
5131
13.51
sec
Rewrite
No
No
No
Yes
1428k
20.16
sec
Rewrite
No
Yes
No
Yes
125k
2.48
sec
Rewrite
Yes
Yes
No
Yes
5225
1.75
sec
32
33. These
features
are
great,
but
how
do
you
ensure
they
kick
in?
…you
can't
guarantee
they
will
33
34. Impacts
of
RewriJng
SQL
Descrip?on
Before
ACer
%
Savings
BI
Report
1
hour
65
sec
98.33%
Job
P
-‐
SELECT
2
hours
15
sec
99.79%
Job
P
-‐
INSERT
5
hours
60
sec
99.67%
Job
P
-‐
DELETE
1.5
hours
30
sec
99.17%
Savings
achieved
from
rewrites
not
from
Exadata.
34
37. Did
I
menJon…
the
opJmizer
doesn't
know
about
Exadata
features.
37
38. Even
when
smart
scans
are
possible,
they
may
not
happen.
Read
consistency,
delayed
block
cleanout,
chained
rows
can
interrupt
smart
scans.
38
39. In
mixed
workload
environments,
the
opJmizer
tends
to
pick
index-‐
oriented
plans
over
scan-‐based
plans.
Even
though
scan-‐based
plans
are
o6en
much
faster.
39
40. Example
1
–
Response
Time
approximately
73
minutes
ExecuJon
Plan
40
44. "Ensuring"
Smart
Scans
Must
achieve
• Make
indexes
invisible
direct
path
mode
• Use
hints
(PARALLEL,
FULL,
etc)
• Instance
parameters
– _serial_direct_read
=
true/always
– _small_table_threshold
– opJmizer_index_cost_adj
• Make
sure
stats
are
representaJve
44
45. SomeJmes
the
problem
is
due
to
a
long-‐standing,
but
undetected,
issue.
StaJsJcs
collecJon
using
esJmate_percent=>30
StaJsJcs
collecJon
using
esJmate_percent=>dbms_stats.auto_sample_size
45
46. SomeJmes
the
results
are
different
from
what
is
expected.
Indexing
StaJsJcs
(histograms
vs
no
histograms)
ds83vw975h9r0
-‐
With
histograms
btafdzsbmg99x
-‐
No
histograms
46
29g25h6xxk2a60
-‐
No
histograms
/
No
Offload
47. SomeJmes
segregaJng
users
helps.
• Create
separate
"group
users"
• Create
LOGON
trigger
for
each
group
• Apply
different
parameter
se}ngs
per
group
• Examples:
– _b_tree_bitmap_plans
=
TRUE/FALSE
– _opJmizer_use_feedback
=
TRUE/FALSE
– opJmizer_index_cost_adj
=
>
100
47
49. Row
by
row
processing
(is
always
a
bad
idea!)
30
us
100
ms
Exadata
can't
fix
this!
50. Some
"odd"
ones
• Parameter
changes
– _opJmizer_max_permutaJons
=
80000
• Helped
one
"class"
of
SQL
• Caused
measurably
higher
CPU
usage
in
parsing
– opJmizer_index_cost_adj
=
10000
• Worked
when
nothing
else
seemed
to
be
effecJve
– _b_tree_bitmap_plans
=
false
• Even
dropped
all
bitmap
indexes
• Delete/lock
stats
on
some
tables
– Helped
OLTP,
o~en
hurt
DW
50
51. Some
"odd"
ones
• Cardinality
feedback
– Numerous
plans
derived
– Very
high
CPU
Service
for
EXEC
calls
waits
• Hard
parsing
of
complex
queries
with
binds
where
bind
opJmizaJon
deferred
unJl
EXEC
phase
• Turn
off
CF,
wait
Jmes
reduced
from
20+
to
1-‐2
secs
51
52. Frequent
use
of
SQL
Profiles
as
"quick
fix"
• Change
session
parameters
• Use
hints
• Rewrite
SQL
• Take
"good"
plan
from
shared
pool
• A•ach
to
"bad"
plan
from
AWR
• Set
force
matching
on
Used
as
stop-‐gap
for
immediate
problem,
but
o~en
forgo•en
and
root
cause
not
fixed.
Can
stop
working.
Force
matching
doesn't
work
if
both
literals
and
binds
present.
52
54. Recap
• There's
a
great
deal
of
good
to
be
achieved
• Behavior
is
frequently
unpredicatable
• Mixed
environments
can
be
nightmarish
• Forcing
desired
behavior
can
force
"bad"
pracJces
to
be
used
• Locking
down
plans
(SQL
Profiles)
isn't
necessarily
a
permanent
fix
(or
shouldn't
be)
• Hope
for
more
help
from
the
opJmizer
in
the
future!
54
55. Remember…
Exadata
is
NOT
a
magic
cure
for
bad
SQL!
55
56. Fix
SQL
(if
possible)
to
achieve
best
results
56