If the suffix "_table" of table names will be changed to "_tbl" the currently longest name "mantis_custom_field_project_table" will be short enough to be created in Oracle databases with the 31 characters of "mantis_custom_field_project_tbl". If it's feasable, the table names could be changed only for Oracle databases to provide backward compatibility for MySQL schemas.

• Does this issue still exist in 1.2.0rc2?
• Are you able to provide or test a fix?

Tested with RC2 (I use prefix "m" and postfix "_t" to avoid length problems)

CREATE INDEX idx_project_id ON m_project_t (id);
-- Already indexed error

INSERT INTO m_user_t....
-- You have to use to_date('blablabla','dd.mm.yyyy') function here to respect DB locale. Fails to insert date with given string. More, why not to use SYSDATE here? It's an momentary user creation, what for is that manual date definition...

CREATE INDEX idx_email_id ON m_email_t (email_id);
-- Already indexed error

ALTER TABLE m_user_pref_t MODIFY(
redirect_delay NUMBER(10) DEFAULT 0 NOT NULL);
-- Already NOT NULL

category_migrate;
-- wrong SQL statement error

And the DB creation script ended with:
Fatal error: Call to a member function FetchRow() on a non-object in D:\WWW\mantis\library\adodb\drivers\adodb-oci8.inc.php on line 355

And TRIGGER endings, quite annoying ( 0011014 ), they must be ended with:
END;
/
Otherwise the whole following code goes to the trigger body.

But its completely useless unless 0010996 is not solved.

Hope this will help.