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  1. Derby
  2. DERBY-3130

Reduce memory footprint of StoredRecordHeader

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    Details

    • Type: Improvement
    • Status: Closed
    • Priority: Minor
    • Resolution: Fixed
    • Affects Version/s: 10.4.1.3
    • Fix Version/s: 10.3.3.0, 10.4.1.3, 10.5.1.1
    • Component/s: Store
    • Labels:
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      Description

      Derby's page cache often has a memory footprint that is much larger than pageSize*pageCacheSize. One large contributor to the footprint is the array of StoredPageHeader objects in BasePage. The memory consumed by these objects can be as large as, and sometimes even larger than, the byte arrays containing the raw page data. (See for instance http://www.nabble.com/How-much-derby-need-memory--tf3307655.html.) Reducing the size of the StoredPageHeader objects could therefore reduce Derby's memory footprint significantly, especially if the page cache is large and contains many pages from tables with small records or from indices.

        Attachments

        1. d3130-1a.diff
          16 kB
          Knut Anders Hatlen
        2. srh.diff
          13 kB
          Knut Anders Hatlen
        3. SmallRecordsTest.java
          0.9 kB
          Knut Anders Hatlen

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              • Assignee:
                knutanders Knut Anders Hatlen
                Reporter:
                knutanders Knut Anders Hatlen
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                  Updated:
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