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1 2 Previous Next 20 Replies Latest reply: Sep 11, 2012 11:59 AM by greybird Go to original post RSS
  • 15. Re: Maximum DB Size?
    740005 Newbie
    Currently Being Moderated
    Looking at the source it would appear to be the number that had activity since the last checkpoint, please correct if wrong.
  • 16. Re: Maximum DB Size?
    greybird Expert
    Currently Being Moderated
    Looking at the source it would appear to be the number that had activity since the last checkpoint, please correct if wrong.
    Correct. Specifically write activity. A checkpoint flushes dirty information in the Btree.
    --mark                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
  • 17. Re: Maximum DB Size?
    932687 Newbie
    Currently Being Moderated
    Sorry if I've missed a definitive answer to this question, but I'm looking for the absolute maximum amount of data that can be stored in a single BDB JE 5.0.x database. Based on EnvironmentConfig.LOG_FILE_MAX of 1Gb for a standard JVM and a maximum log file name of ffffffff.jdb, I calculate that the absolute maximum environment size is about 2.5 Zb. Is that correct? If that is correct, is it possible for a single database to use all of the available environment space? In other words, is it possible for a single database to be 2.5 Zb? Thx.

    -Randy Clegg

    Edited by: user4399464 on Sep 10, 2012 10:56 AM
  • 18. Re: Maximum DB Size?
    greybird Expert
    Currently Being Moderated
    The number I get when multiplying 1 GB by 0xFFFFFFFF is: 4,611,686,017,353,646,080. This is maximum size of the log. However, we've never had a disk large enough in-house to create a log this large.

    Also note that the max log size is not the same as the max data size (record data). Each record has overhead -- metadata. In addition, by default the log is only 50% utilized -- see http://docs.oracle.com/cd/E17277_02/html/GettingStartedGuide/logfilesrevealed.html.

    --mark                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
  • 19. Re: Maximum DB Size?
    909806 Newbie
    Currently Being Moderated
    Also, once log size exceeds RAM by a certain multiple, cleaning stops progressing, and the amount of wasted space begins to grow forever. So in practice RAM is the limiting factor for a functioning DB.
  • 20. Re: Maximum DB Size?
    greybird Expert
    Currently Being Moderated
    Good point, thank you.
    --mark                                                                                                                                                                                                                                   
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