Scenario
Kept getting database connect lost error when trying to delete repository objects such as ER entities, relationships, tables from ER diagram or Designer Editor.
Environment
Oracle 10g Designer
Version: 10.1.2.0.2
Configuration: 4.0.12.97.6
Build: 10.1.2.6.18
Oracle 10g Database
SQL> SELECT * FROM v$version; BANNER ---------------------------------------------------------------- Oracle DATABASE 10g Enterprise Edition Release 10.2.0.4.0 - Prod PL/SQL Release 10.2.0.4.0 - Production CORE 10.2.0.4.0 Production TNS FOR 32-bit Windows: Version 10.2.0.4.0 - Production NLSRTL Version 10.2.0.4.0 - Production
Solutions
SQL> CONNECT system/orcl Connected. SQL> ALTER system SET "_optimizer_cost_based_transformation"=off scope=BOTH; System altered.
See http://forums.oracle.com/forums/thread.jspa?threadID=625348&start=15&tstart=209
for details.