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  1. Derby
  2. DERBY-4537

Update on tables with blob columns streams blobs into memory even when the blobs are not updated/accessed.

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    Details

    • Type: Improvement
    • Status: Closed
    • Priority: Minor
    • Resolution: Not A Problem
    • Affects Version/s: 10.6.1.0
    • Fix Version/s: None
    • Component/s: SQL
    • Labels:
      None
    • Issue & fix info:
      Repro attached

      Description

      While investigating DERBY-1482, I wrote a simple program to see the behavior of a simple update (without any triggers) of a table with blob columns.

      The update is on a non-blob column of a table with blob volumns.

      When this update is made with limited heap memory, Derby runs into OOM error.

      I tried another table similar to earlier table but with no blob column. An update on that table does not run into OOM when run with same limited heap memory.

      I would have expected the update to pass for table with blob column since we are not referencing/updating the blob column. But it appears that we might be streaming in blob column even though it is untouched by the update sql.

      I wonder if working on this jira first will make the work for DERBY-1482 any easier or better yet, will it make the problem with DERBY-1482 go away? Will attach a reproducible program for this soon.

        Attachments

        1. derby4537Repro.java
          2 kB
          Mamta A. Satoor

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              • Assignee:
                mamtas Mamta A. Satoor
                Reporter:
                mamtas Mamta A. Satoor
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                • Created:
                  Updated:
                  Resolved: