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  1. Derby
  2. DERBY-4590

You can drop a file-system database from a directory named "memory"

    Details

    • Type: Bug
    • Status: Closed
    • Priority: Minor
    • Resolution: Fixed
    • Affects Version/s: 10.6.1.0
    • Fix Version/s: 10.6.1.0
    • Component/s: JDBC, Services, Store
    • Labels:
      None

      Description

      With both the embedded and network client drivers, it is possible to create a file-system database and drop it, if you put it in a directory named "memory".

      I found this out by accident when I accidentally typed "memory/mydb" instead of "memory:mydb" to create an in-memory database.

      If you call the directory something other than "memory", you can't drop the db:

      ij> connect 'jdbc:derby://localhost:1527/subdir/mycdb;create=true';
      ij> create table t(c int);
      0 rows inserted/updated/deleted
      ij> connect 'jdbc:derby://localhost:1527/subdir/mycdb;drop=true';
      ERROR XBM0I: DERBY SQL error: SQLCODE: -1, SQLSTATE: XBM0I, SQLERRMC: Directory subdir/mycdb cannot be removed.

      But if you do exactly the same thing specifying "memory", the drop succeeds:

      ij> connect 'jdbc:derby://localhost:1527/memory/mycdb;create=true';
      ij> create table t(c int);
      0 rows inserted/updated/deleted
      ij> connect 'jdbc:derby://localhost:1527/memory/mycdb;drop=true';
      ERROR 08006: DERBY SQL error: SQLCODE: -1, SQLSTATE: 08006, SQLERRMC: Database 'memory/mycdb' dropped.

      When you do this, the "memory" directory continues to exist, but the database directory under it is removed.

      Here are similar examples using the embedded driver:

      ij> connect 'jdbc:derby:subdir/mydb;create=true';
      ij> create table t(c int);
      0 rows inserted/updated/deleted
      ij> connect 'jdbc:derby:subdir/mydb;drop=true';
      ERROR XBM0I: Directory subdir/mydb cannot be removed.

      ij> connect 'jdbc:derby:memory/mydb;create=true';
      ij> create table t(c int);
      0 rows inserted/updated/deleted
      ij> connect 'jdbc:derby:memory/mydb;drop=true';
      ERROR 08006: Database 'memory/mydb' dropped.

      Some part of Derby seems to think you actually created an in-memory database, although you did not.

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              • Assignee:
                kristwaa Kristian Waagan
                Reporter:
                chaase3 Kim Haase
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                • Created:
                  Updated:
                  Resolved: