DBMS_CHANGE_NOTIFICATION - synchronous or asynchronous?

Similar Questions

• Difference b/w WebService synchronous and asynchronous WebService?

  Hello friends... !
  What are the main differences b/w WebService synchronous and asynchronous WebService? What is the information essential to their topic about SOA?

  Hello

  There is no difference between Asynch and sync in terms of flow, or good business logic
  the only difference is in web synchronous service feels the responsibility to give the answer to the applicant
  but asynchronous, you call the web service to give the answer...

  more there is a limit for a time limit for the bpel process to be carried out for synchronous. . but is not asynchronous. .

  There is also a slight difference in the wsdl. .

  Try it for yourself. .

  Thank you

• CDC Logminer synchronous and asynchronous

  I have to configure CDC Logminer.
  My source is oracle.
  I want to know what is the difference between CDC Logminer synchronous and asynchronous.
  And in the oder to configure do them I need to do anything beside the database other than in ODI. If yes what should I do?
  And also want to know what I have to do in ODI also
  
  I'm really grateful if anyone can help me with this.
  Thanks in advance
  
  Published by: user10390682 on 27 Sep, 2010 12:19

  Synchronous LogMiner is like putting triggers on tables system, be careful. If you are using asynchronous, logminer will find the changes, but there may be a time lag before you - when the db allows to do its stuff logminer, could be up to two minutes later that I saw, if the database is busy.
  You don't need to do something else in the database, and in ODI you use just the "Journalisé Data Only" box on the interface to pull changed lines.

• Difference between synchronous and asynchronous service (Process BPMN).

  When we create new BPM process jdeveloper gives 4 options including easy and synchronous service.

  I want to know how they differ logically because the two models look same!

  In an asynchronous process, the starting node is exposed as a "unique sense", so if you see the wsdl for this (port type section), you will see only the entries and no results. This means that the appellant is not expected that the process at the end. In a synchronization process, the web service to the starting node interface is "track two", request/response...so you will see both and input and output in the section type of port. the appellant awaits the response of the process.

• Synchronous vs. asynchronous

  Hello
  
  I get request timed out of exception when you call a Synchronous BPEL service asynchronous BPEL service.
  
  Am in the phase of recognition and created an asynchronous bpel with a delay of 5 seconds and named using a synchronous BPEL but still am getting an error timedout
  The process called async is finished after a wait of 5 seconfs, but even in this case the synchronization process is waiting for the answer
  
  All citing the same asynchronous service using an another async bpel service its works very well.
  
  why I get this error while an async bpel service is called using a synchronization service
  
  Please help me understand

  Large.
  If you can mark my answers as useful or response please.

  See my explanation here:
  Re: Unable to receive the message of an asynchronous service - BPEL

  Arik

• Synchronous and asynchronous BPEl process

  Hi all
  
  1. when we can create a synchronous bpel process
  
  2. when we create a synchronous bpel process
  
  3. when we can create empty bpel processes
  
  4. how to deploy a project using a script? with the example.
  
  Thanks in advance...

  4. how to deploy a project using a script?
  http://jianmingli.com/WP/?p=2584

  1. when we can create a synchronous bpel process
  Synchronous process must create in case if you expect the answer immediately.
  e.g. it is useful in case if you use a card database as partner link in the BPEL process. Because the data base of operation of the adapter used to give the answer immediately.

  2. when we can create asynchronous bpel process
  Asynchronous process must create in case if you when will come answer are not have limitation in time.
  Example:-assume that if you have a single loan process in which we are citing some of the webservices (ex-United Star ready, loan HDFC) who will send interest charges in its response, but in this case the answer can come at any time. Until that time there need to wait an indeterminate BPEL process. If the BPEL Sync process will be used in the above case, then the BPEL process will expire and which will report to the failed State.

  3. when we can create bpel processes empty
  Define the Service later: Select this option to create an empty BPEL process service component without activities.

• Meet a synchronous to asynchronous BPEL (how?)

  Good afternoon!
  
  Have an asynchronous BPEL with an exposed Web service.
  
  I need to get back a BPEL any information at this point, it is called (for example a chat ID). And then continue its own asynchronous process.
  
  Is this possible?
  
  Tank You!

  Too many questions and I'm really not sure about the answers. Do your synchronization process rather than async. In the process, you add replyOutput after the receive activity. Continue to add activities below replyOutput. If your synchronization process includes elements async as a human task, she automatically will behave like an asynchronous process and gets dehydrated in these activities. How about this?

• Synchronous or asynchronous mode

  Small question. I've just implemented a new DataGuard via DGMGRL configuration. When you query for the primary and the standby site 'display the verbose "db_name" database, it is said that the LogXptMode is ASYNC but the log_archive_dest_1 doesn't have the word ASYNC in the definition. He always uses ASYNC even if it is not explicit in the newspaper archive dest? DGMGRL configuration overrides this setting? Thank you.

  A few points about your question:

  (1) LOG_ARCHIVE_DEST_1 should point to a destination local - no SYNC/ASYNC in the game, then
  (2) the DG broker will change the parameters of the primary LOG_ARCHIVE_DEST_n initialization depending on the Standby DBs logxptmode property
  (3) the default value is version dependent. 11 g, it is by default Async
  (4) always mention your version (select * from version$ v) so

  Kind regards
  Uwe Hesse

  "Don't believe it, try it!
  http://uhesse.com

• How to make the instance of oracle bpm asynchronous process?

  I want to create a bpm processes that start as asynchronous. Can someone tell me how to do it and test it?
  Should I first define the structure of data/xsd? Thank you

  It's pretty easy.

  Double-click the Message of your BPM process start event and then go to the implementation tab expand the "Advanced" pane by clicking on the icon "+". Here you will see a button that allows you to make your process "Synchronous" and "asynchronous". Choose the mode you want.

• Firefox redirecting not when you use the script Window.Print

  Have a simple java script on a Web page to display the print dialog box before the redirection to another page.

  < a onclick = "javascript:window.print()" href ="Screen.php" > print, and continue < /a > "

  When the print dialog box will appear if you print it does not redirect but remains on the page. If you cancel printing, it will go ahead and redirect to where it is supposed to go. Worked fine before the last update I was wondering if there was a work around for this or if anyone was aware of this.

  The inconsistency is confusing. If you change your onclick to the following code, you can see a difference of synchronization in the appearance of the confirm dialog box which may be related to the problem. Maybe printing went from synchronous to asynchronous and now the navigation is attempted at a time when it is not allowed?

  onclick="window.print(); if(!confirm('Finished printing?')) return false;"

• Screw vs Express SoftMotion function blocks

  Hello

  Are there differences between express screw SoftMotion function blocks? I intend to drive a servomotor through a NI 9505. Examples AND show how using function blocks, but I've been advised to use the screw Express instead, work around odd behavior when using a simulated axis (http://forums.ni.com/t5/LabVIEW/SoftMotion-quot-Update-Buffer-quot-VI-refuses-to-take-more/m-p/22508...

  Thank you!

  Hi JKSH,

  If I booted up a new application, I would use screw Express on function blocks. Here is a list of things to consider when choosing:

  1. By default, function blocks are asynchronous. They run on the rising edge of the entry "run" and are carried out when the output "done" is high. They do not block and function block architecture will almost always call the same function blocks again and again in a loop. You control the flow of execution with the 'run' and 'done' entry and exit. Screw Express, on the other hand, are synchronous by default. They don't have an entry not "run" and instead start running as soon as they are called. They block also until the end screw Express can be converted to asynchronous by right-clicking on them and by changing the "calendar model. When you change the calendar in asynchronous model, the Express VI will now act exactly like a function block.
  
  
  2. In general, you should never mix asynchronous and synchronous API. Your application should be one or the other. If it is possible to have safe synchronous and asynchronous calls, you must be very careful and really know what you're doing.
  
  
  3. To my experience, write simple applications is easier with a synchronous API, and more complex applications are better suited to an asynchronous API. Since blocking synchronous calls, you need more loops in your application and it can become difficult to maintain.
  
  
  4. There is also the property node / API call, on which are based the functional blocks and screw Express. You can do a right click on a function block or Express VI and convert it into a Subvi to see the underlying code. Then the function blocks and screw Express can be pleasant to work with, you must sometimes lower level control that is offered by the property and invoke nodes.

  I looked at your other post and it seems that you meet one of the intricacies of asynchronous calls. In point 1 above, I mentioned that function blocks increase sensitive edge on the execute line. In your modified sample and the original sample, the 'Update buffer' function block is executed when space becomes higher or equal to the "size of the Contour data. In the original example, the size of the table is 40, but in your example, it is 100. We will follow the stream through the example:

  1. We do nothing in the first round since we do not see a rising edge of the signal "run" "Initialize the buffer" until the second iteration.
  
  
  2. At the beginning of the second iteration, we initialize the table with 20 points, leaving 20 spaces available. This function block can take more than one iteration to complete, so that the loop can run several cycles before the release of "Done" is set to true. In this case, the next block runs.
  
  
  3. Then we start the move of contour. No point is taken in the buffer zone This occurs in the part of the user rather than the scan code.
  
  
  4. Then, we see that there are 20 spaces available, so we add more than 20 points to the buffer, leaving us with 0 beds available. This means that in the next iteration of the loop, the signal "run" function block 'Update buffer' will be false. This is essential to the functioning of the example.
  
  
  5. Since there is no abandonment called, we have a loop around back.
  
  
• Each scan, SoftMotion takes a point in the buffer zone. Finally, the number of available points will be 20. When this happens, the entry "run" will switch from false to true on the 'Update buffer' function block and 20 points more will be added to the buffer. This cycle continues until you stop.

So, what was wrong with your changes? You did the size of the table 100 points. If you look at the steps above, you will see that in the example, we have 40 points in the buffer before taking points. If you increase the size of the table to 100, it means that there are 60 places available. However, 60 is always higher than the "size of data contours" (which is 20) and so the entry "run" function block 'Update buffer' will never wrong; We have always more available space than the "size of data contours. Since "run" is sensitive edge up, we are never really new data in the buffer, and so you get only two cycles that you initially put in. I agree that it is difficult, but it's exactly as function blocks are supposed to work and are certainly something to think about when you use the asynchronous API.

Thank you

• VISA READ timeout error - several GPIB resources

  Hello

  I'm working on a network 3 GPIB instruments (Optical Attenuator, amplifier in fiber, spectrum analyser), controlled using VISA sessions in Labview. When it is run separately, the three corresponding screws (which are located in three different Labview projects) works as expected. However, when they ran at the same time, one gives them timeout-1073807339 VISA READ errors. These errors seem to occur when another instrument is sending / receiving data / instructions at the same time that she is.

  The exact context of the error is either:

  -an another VI is running, which includes sending several requests and responses every 100 ms, reading

  -by failing VI starts, I get an error of waiting time among the first Subvi containing a VISA READ operation to perform (sometimes initialize.vi (in situation 1), sometimes one of the subVIs connected the rest State (State 0) on the time-out of the structure of the event).

  or:

  -the default VI is running,

  -by starting another VI, which includes repeatedly sending requests and reading the responses, the failing VI up a mistake among the first Subvi containing a VISA READ operation to run (one of the subVIs linked the State of rest (0) on the time-out of the structure of the event).

  What I tried:

  -gradually increasing the delay between the VISA WRITE and READ operations to the relevant instrument (from 10 ms to 10 s), without success. More surprising are my observations which, by operating this single VI, increasing WRITE it / READ delay results in the same timeout errors. I have found no mention of such behavior through research google and forum. I hope that this may point to a solution to the main issue,

  -switching between synchronous and asynchronous VISA WRITE / READ operations.

  -reorganization of the network GPIB to a star to a linear topology topology (three instruments have different GPIB addresses in case anyone is wondering).

  My thoughts:

  It seems to me that the error is related to a delay introduced between a VISA request and its read operation by the transmission of another query associated another instrument in the same network GPIB. But I have no idea why pass a query to another instrument would introduce such a delay, or why this delay would result in a timeout error (and only an instrument, while writing / reading in each pilot screws are basically the same). Hopefully a more experienced Labview-er will be able to shed some light on my problem.

  Included is the project that contains the default VI (main.vi) and the driver custom made use of.

  There are a number of ways. If you want to keep separate projects for instruments, you can use semaphores often slandered around calls for screws in each project. Locking is not expected or predictable, but it would give controlled access to the GPIB resource.

• WebDAV, and type last modified information file empty

  I use LV2013 SP1 and working to replace the existing features of FTP with WebDAV.

  For this task, I need to get a list of files (*.tdms) on the RT (cRIO) and allow the user to select those for the transfer.

  My current method of FTP displays the name, date of & size in a list for sorting and selection box.

  No matter if I use synchronous or asynchronous WebDAV live to retrieve a list of directory, cluster type last modified info files elements and are empty.  The RT has installed Server WebDAV 13.5.0 .

  

  I noticed that the type is filled for text (text/plain) files, but modified is always empty.

  I'm guessing that there is no such thing as the MIME type of the TDMS files?  I do not need this information for sorting.

  However, the modified information is very important for my applications & users to sort the list of files.

  This can be a problem with all the parameters of the RT or missing software?

  Thanks for any suggestions and assistance.

  James

  The question has been attributed to 513004 car

  The details of the problem...

  • 13.5.0 & 14.0 WebDAV server
  • Objectives of the RT with VxWorks
  • The NI_WebDAV.lvlib, Listing.vi directory does not return a last modified values in the FileInfo.ctl table.

  

  James

• undetectable exception

  I use xhr to access local file. And problems to handle when file not found.

  If I demand syncronious - its fine.

  var xhr = new XMLHttpRequest();

  XHR. Open ("GET", "local:///data/leonardo_da_vinci.yml", false);

  try {xhr.send () ;} catch (e) {console.log (e)}}

  But if syncronious - I can't catch exception

  var xhr = new XMLHttpRequest();

  XHR. Open ("GET", "local:///data/leonardo_da_vinci.yml", true); //<-- here="" "true"="" means="" async="">

  try {xhr.send () ;} catch (e) {console.log (e)}}

  

  Have you tried to add onload and onerror for the xhr object functions? Example:

  xhr.onerror = function (error) { ... }
  

  Synchronous and asynchronous flow will be different. In most cases, it is not often a good reason to go synchronous (i.e. blocking.)

  Additional examples can be found here:

  http://www.html5rocks.com/en/tutorials/CORS/

  http://www.html5rocks.com/en/tutorials/file/xhr2/

  EDIT: The reason for which you do not catch the exception is what asynchronous means that the code will continue to run; We wait to see if send() is successful or not. The asynchronous approach to implement appropriate reminders to be alerted to success, errors, etc.

• 3rd party such as san replication solution: strategy

  Dear Experts,

  Can you please share some of your ideas.

  Oracle DataGuard comes free with Oracle Enterprise Edition (EE). The only reason why a company could NOT use Oracle DataGuard is because they are not on the ERA and the cost of upgrading to EE just to use DataGuard does not justify the price.

  With 3rd party such as san replication solution. (for example hp3par)

  It is obvious that the all-flash backup can be quick.

  What should be the strategy to have DR site get a few seconds, if the primary site failed for some reason any

  1. daily incremental backup with RMAN. And archive backup runs for every 1 minutes

  2. so that the DR site facing up and running within 60 seconds, it still requires too much time to restore the database on remote site and have archive APPLIED setpoint

  What could be the solution with san replication? RTO = 60 seconds

  Thanks ivw

  Hello

  Great topic, I'll try to summarize all this in a post.

  I have worked with HP EVA for a few years and I must say that I have used many of the features of replication - HP EVA Business Copy (local replication) and HP EVA continues access (remote replication) as well - for the oracle database and other applications as well. Most storage systems use copy-on-write to create two points in time of the LUN (snapshot) image or clone LUN using cow again.

  Of course, like other people, said earlier the replication SAN is block based, in the same way with Dataguard, you have synchronous and asynchronous replication. When your data is written to the data files it usually goes in storage cache and then is pushed down the disc as soon as it will be more efficient, at the same point, replication is pushing data to the Dominican Republic. The same way with Dataguard if you use synchronous replication that you won't get you "speedy return" until the blocks of primary storage has been written for DR storage system.

  I never had problems with replication to be honest. I used a lot of copy of databases of production using local replication. For example if you want to quickly test a patch on the production system, you can create a snapshot that will only increase with the amount of changes you have made. The only concern is nowadays though we use ASM so if your diskgroup names are the same in DEV that the PROD does not work the approach that I mention.

  Regarding remote replication - because you do not have Dataguard more every time you failover to the Dominican Republic to your database will pass by instance recovery!

  Regardless of the type of replication is not the speed but the latency of the network - SAN or Dataguard, you will always have a penalty of a long replication distance. The biggest typical WAN latency factor is the speed of light, via fiber optic cable, which is about 124 miles per millisecond. Based on that you can calculate what would be the round-trip latency time.

  Indeed for many people SE installation choose DBvisit Standby to manage their databases on hold. I did the installation of the couple and it is really simple and works out of the box. However, your RPO depends on how often you switch your redologs and how many times you ship them to the backup site. You must configure dbvisit to spend with each log file (all the 5,10,15 minutes) OR configure archive_lag_target to configure OR use both at the same time. Also, you can store a copy of the archivelogs on a separate location just in case, for example, an NFS share.

  And finally my five cents on RAC on Clusters of extended - be careful with this one. Each of the nodes in the extended database cluster need access to both storage (primary and DR) systems. You must also third location to store a voting quorum disk, usually an NFS share. It is also very important to note that the latency between the nodes is of crucial importance due to global cache activity.

  Kind regards

  EVS