Slow connection when connecting to 10gR2 DB. (4251104)

When trying to connect to a 10gR2 database it takes a really long time to connect.

An option other than "Show all Users" is enabled under Schema Browser - Data, causing a query to be ran searching for users with this criteria. The query can take a long time to execute depending on the number of users, making the connection slow.

WORKAROUND 1:
1. Select View | Options | Schema Browser - Data.
2. Check to see if any options other than "Show all users" are checked in the User\Schema List section.
3. If this option is not checked, then could be causing the slow connection.
4. Check "Show all users" and Apply the changes, then try connecting again.

WORKAROUND 2:
If working on a 10g database, gather statistics on their data dictionary.

WORKAROUND 3:
If using a setting other then  "Show all users", set hidden Oracle parameter "_optimizer_cost_based_transformation" OFF.

CREATE OR REPLACE TRIGGER logon_trigger
  after logon on USER.schema
begin
  execute immediate 'alter session set
"_optimizer_cost_based_transformation"=off';
end;

Refer to Note 313746.1 on MetaLink :
      Problem - "Oracle 10G query is slow compared to Oracle 9i.,"
      Solution - Alter session set "_optimizer_cost_based_transformation" = OFF;

STATUS:
An enhancement request has been submitted to Development for consideration in future release of Toad for Oracle.