What's the downside of very small checkpoint retention time?

I've been reading the 11.2g Streams documentation and while I see what checkpoint_retention_time is (how long checkpoints remain and thus how close to required_checkpoint_scn the system will auto-advance first_scn and start_scn to), I remain unclear on what the effects on the system are and what the downside is of a very short retention time.
So what exactly is the downside of keeping checkpoint_retention_time at a day or less? Will it cause problems if streams replication is down for longer than the retention time? (Say I have retention set to 1 day and one of the other database instances is down for longer than a day -- will LCRs be "lost" due to the checkpoint being purged? Or will checkpoints not be purged if required_checkpoint_scn is not advancing? (As I understand things, it won't advance if replication is down to another instance)) Are there other problems?
And how often does the purge happen? Say I set the retention time to 0.25 (so 6 hours). Will first_scn and start_scn be updated every six hours?
I'm asking because we'd really like to have as few archive log DBF files on disk as possible).

I've been reading the 11.2g Streams documentation and while I see what checkpoint_retention_time is (how long checkpoints remain and thus how close to required_checkpoint_scn the system will auto-advance first_scn and start_scn to), I remain unclear on what the effects on the system are and what the downside is of a very short retention time.
So what exactly is the downside of keeping checkpoint_retention_time at a day or less? Will it cause problems if streams replication is down for longer than the retention time? (Say I have retention set to 1 day and one of the other database instances is down for longer than a day -- will LCRs be "lost" due to the checkpoint being purged? Or will checkpoints not be purged if required_checkpoint_scn is not advancing? (As I understand things, it won't advance if replication is down to another instance)) Are there other problems?
And how often does the purge happen? Say I set the retention time to 0.25 (so 6 hours). Will first_scn and start_scn be updated every six hours?
I'm asking because we'd really like to have as few archive log DBF files on disk as possible).

Similar Messages

  • The text is very small on the dropdown menu of the new adobe reader XI version 11.0.07, can I make it bigger?

    The text is very small on the dropdown menu of the new adobe reader XI version 11.0.07, can I make it bigger?

    Hi,
    Please check the solution posted here:
    Opened AR today font size in super small, went to "preferences" and so on, did changes, nothing works, what's the deal???
    Best,
    Luc

  • How to increase the icons of creative cloude ? The icons permanecm very small and can not see properly.

    How to increase the icons of creative cloude ? The icons permanecm very small and can not see properly.

    Hold down Control and scroll down with the mouse or trackpad.
    Regards,
    Captfred
    That's the screen zoom function activated by CNTL scroll up to zoom and CNTL-Scroll down to unzoom.

  • When I start Firefox using Windows 7 the screen is very small and I must hit Ctrl-+ to enlarge it.

    I just switched from Windows XP to Windows 7. Now when I call up Foxfire the page is very small (about 1/4 size). I must click on Ctrl-+ several times to enlarge it. Is there any solution to avoid all this clicking?

    Reset the page zoom on pages that cause problems: <b>View > Zoom > Reset</b> (Ctrl+0 (zero); Cmd+0 on Mac)
    * http://kb.mozillazine.org/Zoom_text_of_web_pages

  • What is the downside of changing from Mac 10.6.8 to Mountain Lion?

    What is the downside of changing from Mac 10.6.8 to Mountain Lion?

    Check here for compatibility of 3rd party Software you may be using...
    http://roaringapps.com/apps:table
    Also note that Rosetta is no longer supported in Lion and Mountain Lion...
    You will need more RAM... Get the Maximum you can for your Mac...
    It is important to get the Correct and Matching RAM
    See Here  >  OWC RAM  >  http://www.macsales.com
    The above site also has videos on how to Install RAM should you need it...

  • I want replace my desktop with a iPad to do emails and Microsoft office work. Can this be effectively done? What's the downside if any?

    I want replace my desktop with a iPad to do emails and Microsoft office work. Can this be effectively done? What's the downside if any?

    I'll go down your list one by one.
    1. Access mail - which I know that the iPad can do.
    Enough said.
    2. Save an excel or word or ppt of PDF attachment for review.
    You can view these types of documents natively on the iPad as Tgara has mentioned.
    3. Open an review and maybe change a excel or word file.
    There are many apps that allow this.  I personally prefer Apples iWork programs, Pages, Numbers, Keynote.  They tightly integrate with iCloud.
    4. Resave such above files.
    With Pages, Number, Keynote you can save/resave files in iCloud and locally.  Also you could use dropbox to save your files on dropbox and provide a way for you to share a folder with coworkers/family and they can add/view/review files from there and you can see the changes on your device.
    5. Reply to a mail attaching a file.
    This is possible in many ways.  From dropbox, or another app you can email files with the share button.
    6. Be able to rename files and store them in specific folders.
    This goes back to dropbox/iCloud.  iOS doesn't really have a traditional file system.  If you save a PDF it isn't saved anywhere you can just open it.  You would have to open an app that supports view PDFs and select the PDF you wish to view.  The same goes for documents, spreadsheets and etc.
    Hopefully this helps answer your questions.

  • When I open a powerpoint presentation with keynote the slides are very small. How do I make them fit a page?

    When I open a PP with Keynote the slides are very small. How do I make them fit the page, like they did in PP?

    I had the same problem.
    Go to preferences, slideshow, and check the box "Scale slides to fit display."
    Hope this helps!

  • What's the Downside of Not Using Creatve MediaSource (Nuvo 200 1

    Hi guys... I found that installing the Creative Media Source leaves a mess on my WinXP. I've left it on but haven't been using it with my 500 MB Creative Muvo 200. I just plop a folder of classical music or 2 and several folders of BBC type spoken word programs into my player and go.
    Reason for asking: I just got a GB player so I can load a wee bit more music and spoken word stuff...more choice while I'm out there!
    However for this player I did not try to have it recognized by Creative MediaSource and went right to updating the player's firmware.
    Then I loaded it with my stuff.
    The one thing that's different is that my PC recognizes this new player as Dri've "F" (my old one is recognized as "M"). No problem... I guess
    Can I uninstall the Creative Media Source?
    What's the downside of not using the 2nd of 2 downloads for MediaSourcebelow)? (Installed & in use apparently with my 500 mb player)
    <B>Filename: </B><B>MuVo_PCAPP_LB__02_6.exe</B>NOMAD MuVo Pack (version .02.6) for Creative MediaSourceCMS-PMUVO-3-LB
    This software update is for Creative NOMAD? MuVo? users with Creative MediaSource? (version .00.54 or later). This NOMAD Pack contains an audio file-naming feature and improvements to file transfer functions. It also extends the ID3 tag display capability of your player.
    To check your Creative MediaSource version number, see ?Notes' below.
    <EM>Added Features or Enhancements:</EM>
    Displays Russian (Cyrillic) ID3 tag information for MP3 and WMA files in your player.</LI>
    Enables the transfer of DRM-protected WMA files using Creative MediaSource.</LI>
    Allows you to determine the file-naming convention of newly created tracks when ripping an Audio CD to your player using Creative MediaSource.</LI>
    <EM>Requirements:</EM>
    <B></B>
    Thanks
    Chaz

    Installing "MuVo_PCAPP_LB__02_6.exeNOMAD MuVo Pack (version .02.6) for Creative MediaSource" is necessary if you want to see your MuVo as a source node in MediaSource. You will get features such as Smart Fit.
    If you do not install it, your MuVo will only appear as a dri've letter under MediaSource's My Computer, and features such as Smart Fit is not available.

  • HT3728 What is the factory preset password on an Apple Time Capsule?

    What is the factory preset password on an Apple Time Capsule?

    public
    is the default "device" password. There is no wireless password since the default network is open.

  • Please advise what is the query to identify a SQL executed time

    Hi all
    Please advise what is the query to identify a SQL executed time.
    eg, a DML executed at 16-Apr-2013 11:45hrs

    Try like..
    select LAST_LOAD_TIME, ELAPSED_TIME, MODULE, SQL_TEXT elasped from v$sql order by LAST_LOAD_TIME desc

  • Why when I open multiple tabs in Facebook, the tabs load very slowly and most times don't load at all?

    Why when I open multiple tabs in Facebook, the tabs load very slowly and most times don't load at all?

    The default of the pref network.http.max-connections has been increased from 30 to 256 in Firefox 6+ versions.
    You can try to decrease the value of the pref <b>network.http.max-connections</b> from 255 to a more modest setting like 30 as used in Firefox 3 versions.
    *https://support.mozilla.com/kb/Firefox+never+finishes+loading+certain+websites

  • I was on a specific site one evening and for some reason the page became VERY SMALL on the screen. No matter what I do I can't get that particular page to enlarge. HELP

    I was on the site pamperedchef.com. While I was on the page the information went from a full size page to a page approx 3x4 inches. I don't know how this happened but every time I try to log onto this site it comes up in that very small size.

    Reset the page zoom on pages that cause problems: <b>View > Zoom > Reset</b> (Ctrl+0 (zero); Cmd+0 on Mac)
    *http://kb.mozillazine.org/Zoom_text_of_web_pages

  • I am using Windows 7 Ultimate - when I go on Firefox, all of the copy is very small. However, the copy is normal size on Windows Explorer. How do I fix this?

    I have a new computer running Windows 7 Ultimate. When I go on-line with Firefox, the copy is very, very small. However, when I go on Explorer, the copy is large and fills my display. How can I remedy this?
    == This happened ==
    Every time Firefox opened

    Many thanks.
    With those symptoms, I'd try the following document:
    Apple software on Windows: May see performance issues and blank iTunes Store
    (If there's a SpeedBit LSP showing up in Autoruns, it's usually best to just uninstall your SpeedBit Video Accelerator.)

  • When using firefox to search and then print, the printing is very small. This doesn't happen when using another browzer? Can I fix?

    When visiting different web sites (fidelity, sutter health , etc) from the Firefox browzer and I try and print, the printing always comes out very small like maybe a size 4 or 6. When I use another browzer it comes out normal size. Is there a way I can correct this? Also you should know I'm not real computer smart.
    Thanks for any help you can provide

    Once you set that preference it should hold that setting. You could try 125% but it might clip the right-side of the page.

  • When i use the text tool the text inside the box is very small almost invisible even when i keep the text size to 72 please help

    I Have the PS CC 2014 installed in my Win7. I have a problem with the TEXT TOOL,when I select the tool and type something in there,the text is very tiny eventhough the size is 72. I have tried all the things,like Preferences changing,tool reset,character resets etc., Please help me its very frustrating!

    Do you see this behaviour on a new Photoshop document?
    Try creating a New document:
    File > New.
    From the Preset menu, choose U.S. Paper (just so we can test what's happening).
    Take note of the Width, Height and Resolution of the document you are creating.
    Select the Type tool, and ensure the font size is set in pt (points), set to 72 pt.
    Click anywhere in the canvas, and start typing.
    Do you still see the problem? If it's disappeared, then check the problem document settings:
    Image > Image Size, what's the resolution and physical width and height of the file?
    Hopefully this will help you discover what's happening to your document.
    Cari

Maybe you are looking for