Exadata and smart scans

Hi,
I have an Oracle RDBMS 11gR2 that runs on Exadata.
I have several processes that run with a full table scans with resonably "huge" tables (up to few GB).
I would expect that a "smart scan" be used to "speed up the process".
The runs are working for alreay hours.
I get execution plans of that kind:
| Id | Operation                    | Name                      | Rows | Bytes | Cost (%CPU)| Time     |
|   0 | INSERT STATEMENT             |                           |       |       | 3532K(100)|          |
|   1 | LOAD AS SELECT              |                           |       |       |            |          |
|   2 |   FILTER                     |                           |       |       |            |          |
|   3 |    HASH JOIN                 |                           | 24634 |   344M| 3532K (1)| 15:42:08 |
|   4 |     TABLE ACCESS STORAGE FULL| DPV_97_130556316111576318 | 24634 |   625K|   400K (2)| 01:46:42 |
|   5 |     TABLE ACCESS STORAGE FULL| DPV_96_130556316111576318 |   194K| 2724M| 3132K (1)| 13:55:26 |
Can someone explainsme how I can check is smart scan is used, via a query?
If not used, can someone explains me how to "enable" and under which conditons I should?
Thanks by advance for any tips.
Kind Regards

HELLO,
If the explain plan shows the storage clause in the plan then the query goes for smart scan.
Query goes to smart scan when below conditions are met.
1.Segment_size>_small_table_target(hidden init.ora parameter)
2.DB Buffer Cache should not have more than 50% data blocks of the table.
3.Dirty buffers in db_buffer_cache should be less than 25%.
Smart scan is applied to queries which goes for full table scans,parlell queries,Index fast full scan.
Hope this will be helpful.
Regards,
Thimmappa

Similar Messages

Exadata Smart Scan

Hi,
Can someone explain me what Exadata Smart Scan is?
How can I see if it is enabled or disabled?
How can I enable it or disable it?
When to use it and when not to use it.
Kind Regards,
Laurent Baylac

Hi,
Basically, SmartScan is an optimization for the transfers from storage cells to database servers. It concerns only direct-path reads (those not going through buffer cache), so it's limited to large reads of big tables (large tables not in buffer cache and/or parallel query).
Optimization includes:
- predicate offloading: some rows are filtered by the storage software
- projection offloading: only the needed columns are transferred
- join offloading: similar to predicate offloading, using a bloom filter to add predicates
- storage indexes: some i/o can be avoided when a memory map ensures that the required rows are not in some blocks
- decompression offloading: decompression is done by the storage cell in the goal to apply predicate/projection offloading
We can say that it has the flexibility and availability of a SAN without the transfer limitation.
Regards,
Franck.

HP Smart scan software and saving

HP Smartscan v 2.70.000 on an HP Desktop and HP Scanjet 9000.
When we scan; say 50 pages using the HP Smart Scanning Software - we can then see all the 50 pages on the screen in the preview section. BUT when we save the scanned document as a PDF it sometimes only saves some of the pages - not all of them. This has only recently started to happen and it is not every time ! Help Regards Nigel

Same problem on my scanjet 7000

Best Practises on SMART scans

For Exadata x2-2 is there a best practises document to enable SMART scans for all the application code on exadata x2-2?

We cover more in our book, but here are the key points:
1) Smarts scans require a full segment scan to happen (full table scan, fast full index scan or fast full bitmap index scan)
2) Additionally, smart scans require a direct path read to happen (reads directly to PGA, bypassing buffer cache) - this is automatically done for all parallel scans (unless parallel_degree_policy has been changed to AUTO). For serial sessions the decision to do a serial direct path read depends on the segment size, smalltable_threshold parameter value (which is derived from buffer cache size) and how many blocks of a segment are already cached. If you want to force the use of a serial direct path read for your serial sessions, then you can set serialdirect_read = always.
3) Thanks to the above requirements, smart scans are not used for index range scans, index unique scans and any single row/single block lookups. So if migrating an old DW/reporting application to Exadata, then you probably want to get rid of all the old hints and hacks in there, as you don't care about indexes for DW/reporting that much anymore (in some cases not at all). Note that OLTP databases still absolutely require indexes as usual - smart scans are for large bulk processing ops (reporting, analytics etc, not OLTP style single/a few row lookups).
Ideal execution plan for taking advantage of smart scans for reporting would be:
1) accessing only required partitions thanks to partition pruning (partitioning key column choices must come from how the application code will query the data)
2) full scan the partitions (which allows smart scans to kick in)
2.1) no index range scans (single block reads!) and ...
3) joins all the data with hash joins, propagating results up the plan tree to next hash join etc
3.1) This allows bloom filter predicate pushdown to cell to pre-filter rows fetched from probe row-source in hash join.
So, simple stuff really - and many of your every-day-optimizer problems just disappear when there's no trouble deciding whether to do a full scan vs a nested loop with some index. Of course this was a broad generalization, your mileage may vary.
Even though DWs and reporting apps benefit greatly from smart scans and some well-partitioned databases don't need any indexes at all for reporting workloads, the design advice does not change for OLTP at all. It's just RAC with faster single block reads thanks to flash cache. All your OLTP workloads, ERP databases etc still need all their indexes as before Exadata (with the exception of any special indexes which were created for speeding up only some reports, which can take better advantage of smart scans now).
Note that there are many DW databases out there which are not used just only for brute force reporting and analytics, but also for frequent single row lookups (golden trade warehouses being one example or other reference data). So these would likely still need the indexes to support fast single (a few) row lookups. So it all comes from the nature of your workload, how many rows you're fetching and how frequently you'll be doing it.
And note that the smart scans only make data access faster, not sorts, joins, PL/SQL functions coded into select column list or where clause or application loops doing single-row processing ... These still work like usual (with exception to the bloom filter pushdown optimizations for hash-join) ... Of course when moving to Exadata from your old E25k you'll see speedup as the Xeons with their large caches are just fast :-)
Tanel Poder
Blog - http://blog.tanelpoder.com
Book - http://apress.com/book/view/9781430233923

Reg: Exadata and /*+ FULL */ hint -

Hi Experts,
Recently, our database got migrated to Exadata environment, and a DBA told me that using the /*+ FULL */ hint in the query increases the query performance.
Doubt -
1) Does it actually enhance performance?
2) I read some articles and got some information that Exadata does some kind of "Smart Scan" and "Cell Offloading" which makes the query efficient. But how does FULL hint contribute here?
This links talks something about this, but not sure if correct - Some Hints for Exadata SQL Tuning - Part III - SQL Optimizer for Oracle - SQL Optimizer for Oracle - Toad World
Please share your thoughts and advise.
Thanks and Regards,
-- Ranit
( on Oracle 11.2.0.3.0 - Exadata )

Ranit -
Lots of good advice given by others. A little more to add to the comments already made...
Using a full hint as a general tuning rule on Exadata would not be a good idea, just like the sometimes proposed notion of dropping all indexes on Exadata to performance is not a good idea. As Mohamed mentions, a key performance optimization for Exadata are the smart scans, which do require direct path reads. Pushing for smart scans is what drives these types of ideas; because, other than the index fast full scan, index scans will not smart scan. However, smart scanning isn't always faster. OLTP type queries that are looking for one or two rows out of many are still usually faster with an index even on Exadata. If you find using a hint like FULL does improve a query's performance, then just as with using hints in general, it's better to determine why the optimizer is not picking the better execution plan, a full table scan in this case, in the first place; and resolve the underlying issue.
What you will probably find is you are over-indexed on Exadata. If you have control of the indexes in your environment, test by making certain indexes invisible and seeing if that helps performance. Indexes that were created to eliminate a percentage, even a large percentage, of rows, but not almost all rows for queries are candidates to be dropped. You definitely want to tune for direct path reads.
This is done by doing index evaluations as described; making sure your stats are accurate and up-to-date; as mentioned by Franck, be sure to gather the Exadata system stats - as this is the only thing that helps the optimizer be Exadata aware. And also, especially if you are running a data warehouse workload, you can look into using parallelism. Running queries in parallel, often even with a degree as little as 2, will help prompt the optimizer to favor direct path reads. Parallelism does need to be kept in check. Look into using the DBRM to help control parallelism - possibly even enabling parallel statement queuing.
Hopefully these will give you some ideas of things to look at as you enter the realm of SQL Tuning on Exadata.
Good luck!
-Kasey

Smart scan not working with Insert Select statements

We have observed that smart scan is not working with insert select statements but works when select statements are execute alone.
Can you please help us to explain this behavior?

There is a specific exadata forum - you would do better to post the question there: Exadata
I can't give you a definitive answer, but it's possible that this is simply a known limitation similar to the way that "Create table as select" won't run the select statement the same way as the basic select if it involves a distributed query.
Regards
Jonathan Lewis

HP Smart Scan Software 2.7 - No Profiles - ScanJet 8390

I have a HP ScanJet 8390 and when I run HP Smart Scan 2.7 all my profiles are missing. I have removed and reloaded 2.7 three times with the same result. I have even attempted to manually import profiles from my wifes laptop (i.e. xml file) without any success. HELP

Same problem on my scanjet 7000

Diff between normal report and Smart forms

Hi Experts,
I am a fresher, i have only a basic knowledge in sap. please help me to improve my knowledge...
I have some doubts???
1) What the difference between normal report(created using SE38 interactive and classic) and smart forms report???
2) whether we will use any even in script and smart form???
Please do the needfull...
thanesh

Hi
in smartforms and in scripts we write a driver program to execute the smatform /script.
we can write the code in the smartform iteself also.
1. The adaption of forms is supported to a large extent by graphic tools for layout and logic, so that no programming knowledge is necessary (at least 90% of all adjustments). Therefore, power user forms can also make configurations for your business processes with data from an SAP system. Consultants are only required in special cases.
2. Displaying table structures (dynamic framing of texts)
3. Output of background graphics, for form design in particular the use of templates which were scanned.
4. Colored output of texts
5. User-friendly and integrated Form Painter for the graphical design of forms
6. Graphical Table Painter for drawing tables
7. Reusing Font and paragraph formats in forms (Smart Styles)
8. Data interface in XML format (XML for Smart Forms, in short XSF)
9. Form translation is supported by standard translation tools
10. Flexible reuse of text modules
11. HTML output of forms (Basis release 6.10)
12. Interactive Web forms with input fields, pushbuttons, radio buttons, etc

What is the diff b/w Sap Scripts and Smart Forms

Hi,
Whats the diff b/w SAP Scripts and Smart Forms..
I need the internal explanation for both Smart Forms and SAP Scripts mean when we execute what happens whether Print Program r Forms starts execution 1st and SIMILARLY FOR SMARTFORMS WHETHER FM'S R FORMS.
Thanks & Regards,
Gopi.

Hi
Difference with SMARTFORMS vs. SapScript(SE71)
The Following are the differences :-
a) Multiple page formats are possible in smartforms which is not the case in SAPScripts
b) It is possible to have a smartform without a main window .
c) Labels cannot be created in smartforms.
d) Routines can be written in smartforms tool.
e) Smartforms generates a function module when activated.
f) Unlike sapscripts (RSTXSCRP), you cannot upload/download Smartform to your local harddisk.
It was said that it was provided in CRM 3.0 version, but not available in R/3. You can download smartforms into Local PC in a XML format. In the same way you can upload this XML format into Smartform. From the smartform editor itself you can call download option, if you are working in CRM 3.0 environment.
In R3 also, you can download into XML format. However, it's not sure about uploading. Refer to the program 'SF_XSF_DEMO'.
In 4.7 Enterprise, other have seen this utlity which is completey missing in 4.6c. There is functionality to downlaod a complete form or only a particular node. (Utilities -> Download form). It will create a XML file and save it in the hard disk.
For others, if you want to download/upload the Smartforms source, you will need the help from the Basis people. What you can do is to create a Transport and then FTP down to your local harddisk. When you need the Smartform source in another system, you have FTP up the Smartforms file back to the SAP server. Finally, the Basis team, will tp it into your system.
g) The protect and endprotect command in sapscript doesn't work with smartforms. For example on a invoice: First data of position no 80. is printed on page one, other data of position no 80 is printed on page 2. And there's nothing you can do about it. Actually, there is something you can do about it. By using a folder node and checking the 'protect' checkbox, everything in that folder will be page protected.
check out this link:
http://www.sap-img.com/smartforms/sap-smart-forms.htm
Reward points if helpful.
Regards,
Swathi.

Excel 2007 and Smart View 9.3.1.4.041

Dear Experts,
We are now working with Excel 2007 and Smart View 9.3.1.4.041, and encounter the problem that ervery time open the protected excel file there would be the warning message "Drawing Objectes in one or more sheet(s) in the workbook are protected. Please unprotect them and try to save again."
Can any one suggest with;
1. How to set the Excel security settings for Excel 2007 to work for smart view?
2. How to avoid the message mentioned above while working with Excel 2007?
3. How to create a protected Excel file to work with Smart View 9.3.1.4.041 both in Excel 2003 and Excel 2007?
Tks
Edited by: Moonlight on May 19, 2010 10:00 AM

I've experiencied similiar problems, though other users may have found a better solution, I've unlocked the spreadsheat, refreshed, and then relocked via a VBA macro. A button object at the top of the spreadsheet was added to make it easier for the users use as well. If there is a better solution I am very interested in this as well.
JTF

Characters such as apostrophes and smart quotes turning into boxes or question marks

We recently upgraded from CF5 to CF7 and are having a problem
with previously saved text that no longer displays correctly. Some
characters (apparently, non-ASCII characters such as curly
apostrophes and smart quotes) are rendering as boxes or question
marks. We recently upgraded to Oracle 10g from Oracle 8i, but this
problem appears to be independent of the database that the text is
stored in. Here is sample code that will illustrate the problem:
<CFSET string1="Department’s">
<CFSET string2="hey—there">
<CFOUTPUT>
string1 is #string1#
<BR>
string2 is #string2#
</CFOUTPUT>
output looks like this:
string1 is Department?s
string2 is hey?there
These are rendered as boxes when viewed in Internet Explorer.
(They show up as question marks when I copy and paste them here.)
The Demoronize UDF helps *some* of the time, but this is
still happening with a lot of text, especially text that gets
pasted from a website into a form, then saved to a database. Does
anybody have a solution for this? This is breaking my applications
and is incredibly annoying. I'd like to either replace the
problematic characters at the time they are displayed, or replace
them when they are input in the database in the first place (and go
back and update all the previously saved data to replace the
problematic characters with plain text equivalents).
Any suggestions appreciated.

I finally isolated the problematic characters so I edited the
DeMoronize UDF (available at cflib.org) by adding the following
text replacements at the bottom:
text = Replace(text, chr(8208), "-", "ALL");
text = Replace(text, chr(8209), "-", "ALL");
text = Replace(text, chr(8210), "–", "ALL");
text = Replace(text, chr(8211), "–", "ALL");
text = Replace(text, chr(8212), "—", "ALL");
text = Replace(text, chr(8213), "—", "ALL");
text = Replace(text, chr(8214), "||", "ALL");
text = Replace(text, chr(8215), "_", "ALL");
text = Replace(text, chr(8216), "‘", "ALL");
text = Replace(text, chr(8217), "’", "ALL");
text = Replace(text, chr(8218), ",", "ALL");
text = Replace(text, chr(8219), "'", "ALL");
text = Replace(text, chr(8220), "“", "ALL");
text = Replace(text, chr(8221), "”", "ALL");
text = Replace(text, chr(8222), """", "ALL");
text = Replace(text, chr(8223), """", "ALL");
text = Replace(text, chr(8226), "·", "ALL");
text = Replace(text, chr(8227), ">", "ALL");
text = Replace(text, chr(8228), ".", "ALL");
text = Replace(text, chr(8229), "..", "ALL");
text = Replace(text, chr(8230), "...", "ALL");
text = Replace(text, chr(8231), "·",
"ALL");

My 3 year-old macbook pro is very slow. I have run disk utility and virus scan with no improvement. The "beach ball" will spin for minutes at a time when opening, closing or changing windows. Apple Store looked at it a few months ago with no help.

my 3 year-old macbook pro is very slow. I have run disk utility and virus scan with no improvement. The "beach ball" will spin for minutes at a time when opening, closing or changing windows. Apple Store looked at it a few months ago with no help. What can I do?

Under CPU: 3.5% user; 5% system; 91% idle; 441 threads; 90 processes.
Under System: out of 2GB - 54.7MB free; 530MB wired; 603MB active; 862MB inactive; 1.95GB used.
Is too much of the system memory tied up? If so, what can I do to free some up?

My itunes account shuts down for no reason. It wont recognize my iphone and there is an issue with network connectivity and itunes. I have already reinstalled itunes and did a syste restore on my computer, firewall checked and virus scan done. Ideas??

My itunes account on windows xp shuts down for no reason. If even try to delete something from my library it shuts down. It wont recognize my iphone and there is an issue with network connectivity and I can't connect to the store. I have already reinstalled itunes and did a system restore on my computer, firewall has been checked, itunes is ok on firewall and virus scan done. Ideas??

Same problem. I can see the itunes store so not a problem with windows firewall. The account is active on my iphone so i know i am not locked out. I can connect the PC to my iphone so i know itunes is working ok. It is just logging into itunes on this pc which doesn't work. Only thing I can think of is that the email address I use for my apple id has been offline for a while and is working again now, I'm wondering whether this has been the case for others who are having this issue?

Have been advised by my email provider (recently blocked account requiring password reset) that they will only reset the password after a proven anti viru and malware scan has been done on ipad and iphone. Is this necessary and if so what do i use

Have been advised by my email provider (recently blocked account requiring password reset) that they will only reset the password after a proven anti virus and malware scan has been done on ipad and iphone. Is this necessary and if so what do i use

As KP has pointed out, there actually aren't any anti-virus programs in the App Store. There are a few that allow you to scan e-mail or stuff like that, and a few that provide you with information about malware and new threats for other systems. But none are available that can scan your iOS device for malware, because the security restrictions in iOS do not permit any apps to have that kind of access to anything. Which means that you also cannot be infected with a virus (unless you have jailbroken your device).
If your account got compromised, that had nothing whatsoever to do with your iPad. Someone simply hacked it remotely. Happens all the time. It's really amazing that, in this day and age, e-mail providers are so ignorant of technology and how their own systems get compromised that they would try to require you to run software that does not exist!

List of script and smart forms(except TNAPR) with output type or print prog

How to find out List of SAP SCRIPT and SMART FORMS (except TNAPR)with output type or print program..I like to chk in output type WMTA whch form should use.kindly help on this

Hi
WMTA is special msg and doesn't create any print: so you can't find a sapscript or smartform to link to it.
WMTA is a message for delivery, so you can find it by NACE trx or TNAPR table (It's the same): infact here it can find only all messages of logistic modules (SD & MM).
The routine ENTRY of RLAUTA20 is called by WMTA and creates a Transfer Order (for WM, Warehouse Management, module), so if you need to create a print for that msg you need to change prg RLAUTA20,
Max

Exadata and smart scans

Similar Messages

Maybe you are looking for