Performance question

Similar Questions

• Sandy Bridge and PCI channels/performance question

  I was doing emergency surgery on my old HP and I remembered that I have a couple of old graphics cards lying around. And that made me think of my collection in constant expansion of hard drives and never less in less free time, backups, and Sandy Bridge platform limited channels PCI and their (real? theoretical?) effect on performance with cards cards additional specifically RAID. If I'm covering old ground, let me know.

  As I understand, there is not much to be gained by installing an old ATI HD2400 Pro or similar in a new computer, what I'm really wondering is - after installing the card and a third running monitor on it - of the main graphics card and related parts of my system would suffer a slowdown similar to what might be expected if a RAID card is installed.

  (And no, I don't mean to revive the heated discussions of Sandy Bridge / X 58.) Is it you like someone ' one, anyone - let them be above!)

  I am just wondering if it might be a worthwhile project to compare benchmarks with and without a second graphics card installed and if someone thinks it would be a logical way to see no effect on the allocation of 570's PCI channels alone, without the complication of a real external RAID array question (and the enormous benefits it would probably).

  everything you need to know here

  http://forums.Adobe.com/thread/854514?TSTART=30

  This has been put to bed in time there...

  Scott

  ADK

• performance question 9 objects shared

  I shared 9 objects 8 that contain dynamic data which I can't really group them into a single sharing object because the shared object must often be deleted... my question is what performance issues I'm going to experiece with this number of shared objects... I may be wrong in thinking that 9 shared objects is a lot... anyone with any experiece using multiple shared objects please answer.

  I used a lot more than 9 SO in an application without a problem. I guess it really comes down is how many clients are connected to those SO and how many times each of them is updated.

• SQL Performance question

  Hello
  
  The following query performs badly when the predicate
  
  AND (v_actionFlag IS NULL or ACTION_CODE = v_actionFlag)
  
  is present. In all executions of the query v_actionFlag will be NULL. In addition, because of the plan when the predicate is included, the returned results are incorrect. We seek to treat rows with the lowest priority. With the included predicate query performs the join, gets 20 lines, sorts, and puts back them rather than getting 20 lines with the lowest priority through the index of QUEUE_TAB0 and return of these.
  
  The questions I have are-
  
  -Why the predicate affects the query in this way
  -What is the difference between the HASH JOIN ANTI and HASH JOIN RIGHT ANTI
  
  
  We were able to remove this predicate as the functionality it supports has not yet been implemented.
  
  
  
  Background
  
  Version of DB - 10.2.0.4
  optimizer_features_enable - 10.2.0.4
  optimizer_mode - ALL_ROWS
  

  Table
  
  - table has approximately 475,000 rows and the statistics are up to date
  
  
  sql> desc queue_tab
   Name                                      Null?    Type
   ----------------------------------------- -------- ----------------------------
   ENTITY_KEY                                NOT NULL NUMBER(12)
   ENTITY_TYPE                               NOT NULL CHAR(1)
   ACTION_CODE                               NOT NULL CHAR(1)
   REPORT_NO                                 NOT NULL NUMBER(12)
   PRIORITY                                  NOT NULL NUMBER(4)
  
  
  
  Indexes
  
  Primary Key (QUEUE_TAB_PK)
  
   ENTITY_KEY                                 
   ENTITY_TYPE                                
   ACTION_CODE                                
   REPORT_NO 
  
  
  Non Unique Index (QUEUE_TAB0)
  
   PRIORITY  
   ENTITY_KEY   
   ENTITY_TYPE  
   ACTION_CODE 
  
  
  
  Cursor
  
  
          SELECT /*+ INDEX_ASC (main QUEUE_TAB0) */
                 REPORT_NO
               , ENTITY_TYPE
               , ENTITY_KEY
               , ACTION_CODE
               , PRIORITY
            FROM QUEUE_TABV01 main
           WHERE PRIORITY > 1
             AND (v_actionFlag IS NULL OR ACTION_CODE = v_actionFlag )
             AND NOT EXISTS
                 ( SELECT /*+ INDEX_ASC (other QUEUE_TAB_pk) */ 1
                     FROM QUEUE_TABV01 other
                    WHERE main.ENTITY_TYPE = other.ENTITY_TYPE
                      AND main.ENTITY_KEY = other.ENTITY_KEY
                      AND main._ACTION_CODE IN ( constant1, constant2 )
                      AND other.ACTION_CODE IN ( constant3, constant4 ) )
             AND NOT EXISTS
                 ( SELECT 1 FROM QUEUE_TABV01 multi
                    WHERE main.ENTITY_TYPE = multi.ENTITY_TYPE
                      AND main.ENTITY_KEY = multi.ENTITY_KEY
                      AND multi.PRIORITY = 1 )
             AND ROWNUM < rowCount + 1
           ORDER BY PRIORITY, ENTITY_KEY, ENTITY_TYPE,
                    ACTION_CODE;
  
  
                                   
  Plan when predicate "AND (v_actionFlag IS NULL OR ACTION_CODE = v_actionFlag )" is present
  
  
  call     count       cpu    elapsed       disk      query    current        rows
  ------- ------  -------- ---------- ---------- ---------- ----------  ----------
  Parse        1      0.00       0.00          0          0          0           0
  Execute      1      0.00       0.00          0          0          0           0
  Fetch       21      5.53       5.40          2     780463          0          20
  ------- ------  -------- ---------- ---------- ---------- ----------  ----------
  total       23      5.53       5.40          2     780463          0          20
  
  Misses in library cache during parse: 0
  Optimizer mode: ALL_ROWS
  Parsing user id: 60     (recursive depth: 1)
  
  Rows     Row Source Operation
  -------  ---------------------------------------------------
       20  SORT ORDER BY (cr=780463 pr=2 pw=0 time=5400939 us)
       20   COUNT STOPKEY (cr=780463 pr=2 pw=0 time=5400872 us)
       20    HASH JOIN ANTI (cr=780463 pr=2 pw=0 time=5400823 us)
   459033     TABLE ACCESS BY INDEX ROWID QUEUE_TAB (cr=780460 pr=2 pw=0 time=4640394 us)
   459033      INDEX RANGE SCAN QUEUE_TAB0 (cr=608323 pr=1 pw=0 time=3263977 us)(object id 68038)
    10529       FILTER  (cr=599795 pr=1 pw=0 time=2573230 us)
    10529        INDEX RANGE SCAN QUEUE_TAB_PK (cr=599795 pr=1 pw=0 time=2187209 us)(object id 68037)
        0     INDEX RANGE SCAN QUEUE_TAB0 (cr=3 pr=0 pw=0 time=34 us)(object id 68038)
  
  
  
  
  Plan when predicate "AND (v_actionFlag IS NULL OR ACTION_CODE = v_actionFlag )" is removed
  
  
  call     count       cpu    elapsed       disk      query    current        rows
  ------- ------  -------- ---------- ---------- ---------- ----------  ----------
  Parse        1      0.00       0.00          0          0          0           0
  Execute      1      0.02       0.00          0          0          0           0
  Fetch       21      0.05       0.05          0       6035          0          20
  ------- ------  -------- ---------- ---------- ---------- ----------  ----------
  total       23      0.07       0.06          0       6035          0          20
  
  Misses in library cache during parse: 1
  Misses in library cache during execute: 1
  Optimizer mode: ALL_ROWS
  Parsing user id: 60     (recursive depth: 1)
  
  Rows     Row Source Operation
  -------  ---------------------------------------------------
       20  SORT ORDER BY (cr=6035 pr=0 pw=0 time=54043 us)
       20   COUNT STOPKEY (cr=6035 pr=0 pw=0 time=962 us)
       20    HASH JOIN RIGHT ANTI (cr=6035 pr=0 pw=0 time=920 us)
        0     INDEX RANGE SCAN QUEUE_TAB0 (cr=3 pr=0 pw=0 time=53 us)(object id 68038)
       20     TABLE ACCESS BY INDEX ROWID QUEUE_TAB (cr=6032 pr=0 pw=0 time=701 us)
       20      INDEX RANGE SCAN QUEUE_TAB0 (cr=6001 pr=0 pw=0 time=533 us)(object id 68038)
       40       FILTER  (cr=199 pr=0 pw=0 time=2048 us)
       40        INDEX RANGE SCAN QUEUE_TAB_PK (cr=199 pr=0 pw=0 time=1975 us)(object id 68037)

  user599445 wrote:
  Hello Justin and Camille,

  Thank you for taking the time to look at it. I changed the query to correctly practice the ROWNUM. I run and traced the query with the predicate IS NULL and without, with each track below. As you both have suggested that the predicate appears to have no impact on the plan does. All feedback is appeciated.

  Mark,

  the obvious problem with the new plan is that no record is filtered by the first NOT EXISTS clause (using anti-join operation), and then for each line an index seek is performed that filters the records only about 14 000. It is the search for index that takes most of the time, gets consistent since he performs about 2 e/s logic by research, in total nearly 1 million.

  The last 456 000 rows are then sorted (top n) and the top 20 are returned.

  A possible problem could be that the optimizer does not switch mode optimization first_rows_N due to the variable binding used in the filter ROWNUM.

  You can try to execute the statement using a literal (ROWNUM< 21)="" instead="" of="" the="" bind="" variable="" to="" see="" if="" it="" changes="">

  I think in this case, it could be much more effective for the QUEUE_TAB0 of the market index in the order requested and perform the two NOT EXISTS clause as activities of recursive filters provided as your ROWNUM predicate is generally rather low.

  Be aware however that is you do not use a "binary" NLS_SORT index parameter can not be used for an operation of NOSORT ORDER BY STOPKEY of CHAR values, so please check your settings NLS (NLS_SESSION_PARAMETERS. PARAMETER = "NLS_SORT") in which case the optimizer will not use the index for sorting. Note that the NLS parameters are customer specific and can theoretically be different for each session / client.

  You can test this by using a query simple top N: SELECT * FROM (SELECT * ACTION_CODE, ENTITY_TYPE, ENTITY_KEY, QUEUE_TAB ORDER OF PRIORITY) WHERE ROWNUM<>

  If it does not use the QUEUE_TAB0 index to stop the sort operation, you might have a problem with the NLS parameters.

  In order to prevent the transformation of the GUESSED you can also try adding a hint NO_UNNEST two subqueries ("SELECT / * + NO_UNNEST * /...") ("in the respective subquery) and you can also try to switch mode FIRST_ROWS (n) using for example the FIRST_ROWS indicator (20) in the body of the request (but which must be done by the ROWNUM predicate).

  Kind regards
  Randolf

  Oracle related blog stuff:
  http://Oracle-Randolf.blogspot.com/

  SQLTools ++ for Oracle (Open source Oracle GUI for Windows):
  http://www.sqltools-plusplus.org:7676 /.
  http://sourceforge.NET/projects/SQLT-pp/

• SQL - pl/sql performance question

  Hi all
  I spent teaching examples reviewed while preparing for certification and stumble on this one:
  "... If you design your application so that all programs that are running an insert on a specific table use the same INSERT statement"that is
  ...
  INSERT INTO order_items
  (order_id, product_id, line_item_id,
  quantity, unit_price)
  VALUES (...)
  
  your application will run faster if you wrap your dml statement in a procedure from pl/sql instead of use the stand-alone sql statement because of less demand analysis and reduced system Global Area (SGA) memory.
  does not include why it is so. I'm wrong that any sql statement will be cached in the SGA any context it is executed (sql or pl/sql)? And also why this culminates at a minimum analysis?
  
  Thank you.

  Timin wrote:
  + "If you design your application so that all programs that are running an insert on a specific table use the same INSERT statement, your application will run faster to cause less demand analysis and reduced the system Global Area (SGA) memory." +
  + Your program are also data manipulation language (DML) errors constantly. » +

  I think that what lies is the following.

  You have an application that makes several calls insertion in the database. Suppose emp table.

  Insert into emp (empno, ename, deptno) values (emp_seq.nextval, 'Test', 1);
  
  Insert into emp (empno, deptno, ename) values (emp_seq.nextval, 1, 'new emp');
  
  Insert /*+ append */ into emp (empno, ename, deptno) values (emp_seq.nextval, 'Frank', 2);
  

  These inserts could be from different applications. This is why the spelling may be different.
  All insertions do not use variables binding, but even if they do, they would use still different cursors because commands insert spelly differently and levels of parameter.

  It is better (more efficient) to call an API instead, who performs the insertion.

  execute emp_pkg.Insert_single_emp( 'Test', 1);
  execute emp_pkg.Insert_single_emp( p_ename => 'new emp', p_deptno => 1);
  execute emp_pkg.Insert_single_emp( p_deptno => 2, p_ename => 'Frank');
  

  The api is pl_sql, then a SQL insert statement.

  procedure Insert_single_emp(p_ename in ename.emp%type, p_deptno in deptno.emp%type)
  ...
  begin
  ...
     Insert into emp (empno, ename, deptno)
     values (emp_seq.nextval, p_ename, p_deptno);
  
  end;
  

  All insert statements three will use the binded settings and avoid new analysis view the SQL insert (time analysis).

  I assumed that the cursor is shared and so this means less CMS as well.

  BTW: it is a requirement of Steven Feuerstein typical/suggestion.

  Published by: Sven w. January 7, 2011 18:25

• WHERE clause order ox performance question

  I do not understand order of execution of a WHERE clause, the use of a complex database
  
  I want to write a SELECT statement with the following condition
  
  ... WHERE (branch = 'main') AND (type = 1) OR (AND the costs-1 = 2).
  
  My question is
  
  < 1 > yoyu can use parentheses within a WHERE clause
  
  < 2 > how you would write such a clause as above if you cannot use parenthesis
  
  Thank you

  Hello

  Yes, you can have parentheses in a WHERE clause.
  I highly recommend to use when you need to use both AND and or in the same WHERE clause, since

  WHERE  (    x
          AND y
          )
  OR      z
  

  is not the same as

  WHERE   x
  AND     (   y
          OR  z
          )
  

  As others have said:

  ( charge -1 AND charge = 2 )
  

  will cause a compilation error.
  Here's the syntax valid and quite reasonable (although somewhat obscure):

  WHERE     (     branch = 'main'
       AND     type    = 1
       )
  OR          (     charge != -1
          AND     charge !=  2
       )
  

• Great performance of 2 TB LUN

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  I have

  noticed on the largest lun performance problems.  Basically, most of my LUN is 1 TB with a couple of 2 TB lun.  The 2 TB LUNS are

  2 GB LUN 1 LUSEd then present to the ESX cluster.

  Due to the need for the partitions of 2 TB, I would format

  them as a storage of blocks of 4MB, so that I can present a 2 TB partition to the

  UM

  When I run tests on partitions (15 GB) small LUN 1 TB coming against the partition of 2 TB 2 TB LUNS from, the performance is significantly lower on the latter.

  Do you know if there is a problem

  from a performance perspective?

  Thank you

  Daniel

  Daniel,

  I can't find it right now, but there is a vmware doc stating that LUN LUSE are a last choice.  Also, whenever I never called him VMW support and told them I'm on Lun LUSE, I get a nice little 'reading' how they are.

  We also see performance 'questions' on them.  They are not slow in itself, because the ridiculous sums cached in our USP1100 buffer a lot of this possibility, but they should be faster.

  We didn't have no other options beside LUSE LUNs, so I went with that.  We move away from Hitachi for that sort of thing, and so I won't have to deal with them more.

  Feel free to send me a private message if you want to talk more in detail

  -Matt

• Satellite L50-B-1N8 - weak wifi signal

  Hello

  So two weeks ago, I bought a new laptop of Toshiba Satellite L50-B-1N8 of Argos.

  He never had too good a force wifi signal (bars never complete - even when sitting next to the wifi router) but I thought it was due to my wifi box and possibly the time of garbage that we had.

  However, I still have my old laptop, and when you check the WiFi side by side, my old portable Samsug picked up the signal full or almost full so this new Toshiba picked up a bar at a push.

  Since then, I took the laptop to my parents and he struggles to get the good WiFi, if no signal there too.

  It's super frustrating because it get wifi, it get just a very weak signal or nothing at all, and as soon as I move my laptop... literally a few centimetres, it will change the wifi signal or my wifi signal is cut and it will be impossible to connect.

  I did everything I can think of troubleshooting to actually factory reset my laptop that none has worked so far. The factory reset seems to have actually done worse, rather better!

  As I said, my router is not the problem here, I have my old laptop that connects very well, as well as two other laptops and mobile devices that all have connected to wifi very well and with full signal!

  I disabled all these wifi devices to see if this is the problem, but that did not help or the other. I also have a booster of wifi in the House, so all devices have full or almost full signal, but it seems of no use for this Toshiba.

  I lose my home, is there anything else I can do? I'm still in the warranty of 30 days of Argos if the laptop is down, but I just can't think of anything to try. I just hope that if the laptop is down Argos will help and either pay the phone or Exchange.

  Any help or advice would be much appreciated. :)

  I think first of all you must check if the wireless performance question isn't related to energy saving settings.

  Go to the control panel? Windows power options.
  Choose the current power plan
  Now, you must click Advanced power settings.

  In Advanced Power settings you will find different options, search for LAN wireless (WiFi) and choose the Performance for both options (battery and power)
  After that, restart the device.

  I hope that this short change might help you.

• L50-B-1NM satellite - wifi only works near the router

  Hi just bought this laptop for my daughter Toshiba L50-B-1NM 15.6 inches processor Ci3 4 GB 1 TB and wifi only works if he was sitting next to the router.

  It will connect to the internet if the ethernet cable is connected, BUT for wifi, the laptop has been sitting almost touch the router. The rest of the House works well.

  Please could you help me before I take it back to the shop and eventually making a fool of myself.

  I'm really not good with technology so if you do not answer could you explain to me like a baby please ;) lol

  Thank you very much, totally disappointed at the moment because it cost me a lot of money for it :(

  Hi maria,

  I think you should consider a fact: the L50-B-1NM Satellite was equipped with an Intel 802.11ac + card agn combo Wifi/BT.

  802.11 AC is a new WLan standard that isn't taken care of by all old WLan routers.
  But of course, the standard 802.11 A / G or N must be supported by older devices correctly.

  I think first of all you must check if the wireless performance question isn't related to energy saving settings. I guess during wifi problems, the laptop uses battery power
  In this case we would use different power plan settings.

  Please check the settings that are in the advanced within the current energy saving Central WLan power settings.

  Where this doesn t help you solve the problem of WiFi signal weak, you should contact the authorized Toshiba maintainer to check the connection to the WLan antenna.

  It may be possible that the antenna isn't properly connected, which is originally a weak WiFi signal.

  Because the laptop is under warranty, it should be fix toll-free number.

  Greetings

• Is a bootcamp VM faster then a virtual machine that is based vmdk?

  Performance question: is a bootcamp VM faster then a virtual machine that is based vmdk? I guess the only reason why make it faster would be to drive, reading and writing.

  Are there other benefits of performance?

  Hello

  Not a bootcamp VM is not really faster like a normal virtual machine.

  I understand your reasoning, but unless you open a lot of clichés about the virtual machine performance is almost identical or similar vmdk founded against based training camp.

  Which btw is highlighting a disadvantage of bootcamp VMs, you can not snapshots.

  Of course, if you start your VM bootcamp in native mode (and not as a virtual machine), you have a performance increase as you then run native on the material.

  --

  Wil

• index rebuild

  During the rebuilding of the index on the production of databases what precautions because a DBA will take? If dba disable the application or not?
  When online index rebuilding, what performance question will come on the production database?
  
  
  Thanks in advance

  Reconstruction on-line during the index of what will be the impact on the database?

  1 space of index segments can be roughly doubled as Oracle retains the original index segment during the reconstruction. It creates a new index segment, he switches rapidly, then deletes the old.
  2 CPU will be consumed
  3 oracle perhaps fully analyze the old index, other index or table.

  If a user makes a request at the time of the index to rebuild which will have an impact on this user?

  a shared lock on the table will be held
  brief exclusive lock tables and indexes metadata will be held during the switch.

• Who will be the best option with Oracle 11 g dd loadbalancing and failover

  We use weblogic 10.3 with multipool with each source of data pointing to each RAC node. The Multipool manage failover and load balancing scenario. With 11g database now, we have the ability to use SCAN where weblogic will point to a service and load balancing/failover happen side DB.
  
  Published by: user1122 on April 12, 2010 10:47

  Stick with MultiPools for now. SCAN will confuse pools WLS and will harm XA if you
  using XA, because WLS assumes that all connections in a pool are identical. If some are
  bad, WLS assumes that all are and can kill all the. We try to ensure that all the work
  in a given transaction goes to a specific node of the RAC, but if the pool is heterogeneous
  We can spoil, and depending on the version of the DBMS, it will suffer performance
  questions to the best and can corrupt and if it gets worse...

• FND_LOBS partitioning

  Hello
  I'm looking for more information on the partitioning table fnd_lobs. Hope someone can help
  What strategy of partitioniting is used for this partition table? If the partition of the range was used, which was chosen as the partitioning column?
  
  Thank you
  MSK

  Hi MSK,.

  I have no need of partition FND_LOBS myself, but I know that certainly, it can become quite large. You are looking at partitioning because you have a specific concern for performance, or simply because you are concerned about its overall growth? If there is a performance issue, did you identify poorly performing questions that could help you decide what partition keys would make sense?

  My Oracle support Document [My Oracle Support Document 829235.1| https://metalink.oracle.com/metalink/plsql/showdoc?db=NOT&id=829235.1], referenced above by Helios, mentions using program name or program_tag as key partitioning, but if most of your documents is from the same module, which is probably not very useful.

  Kind regards

  John P.
  http://only4left.jpiwowar.com

• A few questions about the management of the partitions when you perform a recovery

  Hello everyone,

  I bought a L505-13Z on weeks there are for personal use and editing of audio work light. In these two weeks, I took the time to explore and test the performance of this computer and judged suitable for my needs because it resists even havier audio work so I'll need, what it is tested. I am really satisfied with this laptop! In any case, some optimizations I did for audio software suffered a few necessary features of the computer, so I need to reinstall the operating system... Basically, I was always used to install only the system drive wiping system, leaving the score of "D: Data" intact. I noticed that this is not the case with the recovery of the system, because after the restoration, system partitions and data disappeared. of course everything is saved on an external drive, but every time I have to restore, I need to copy everything back from the backup drive? I missed the point of this - it's exactly like having all my data saved on the system partition. What, then, is the need for the data partition?

  Is there a way to recover and leave intact the partition 'Data'?

  My second question is if it is possible to change the size of the partitions somehow? I think it's a bit pointless to have 230G of free space for the system partition. 100G is sufficient for my needs, and I could use the 130G remaining for the data partition, I don't know why the drive is simply divided into two by default... (I am aware that a change of size of partition must erase all data on the disk).

  Thank you all in advance for any help!

  If you use the procedure of recovery disc HARD - http://aps2.toshiba-tro.de/kb0/HTD9102IR0000R01.htm - structure and the data on the second partition will not be deleted.
  So, if you want to install OS using HARD drive recovery option you can move all the important data of the C partition to D partition.

  The whole HARD disc will be deleted if you use recovery DVD for installing the OS.
  ----------------------------------------------------------
  You should not change the partition structure because it can have a negative influence on the recovery procedure more HARD drive. It can happen that data recovery will be will be more found.

  Please note: second partition D is not a kind of system partition or recovery. This is normal and usual HARD disk partition. He is saved just Toshiba recovery image in the folder called HDDRecovery.
  You can do it, I did too, it is better to enter the properties of this file and set it as invisible.

  You will not be irritated by this file. It's there, but you can not see and there is no way that you can remove it somehow. Use this partition as usual. Create own folders, copy data here, just do your usual work.

  Any other questions?

• List of questions to verify the performance and maintenance?

  Is there an online list of questions to verify the performance of Vista SP 1?

  A reasoning to install SP2 or SP3 immediately?

  I had to do a direct upgrade from XP sp2 to Vista and seems to work very well.

  Thank you

  Kenny

  Sunday, August 8, 2010 13:13:36 + 0000, PCKenny wrote:

  Is there an online list of questions to verify the performance of Vista SP 1?

  See Lorien - good suggestions.

  A reasoning to install SP2 or SP3 immediately?

  Yes. Service Packs resolve problems and improve safety. You should
  be always up to date with them.

  Ken Blake