Minor 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.
Attachments
Attachments
Issue Links
- is related to
-
DERBY-4428 Add proper delete mechanism for in-memory databases
-
- Closed
-