The current version of Toad requires users to have CREATE/INSERT/SELECT privileges to global temporary tables. So Toad can create and insert rows in QUEST_OPTI.QUEST_TEMP_EXPLAIN temp table. Because of the restricted read-only database, user would like to create the temporary table in a central schema, grant access to that temporary table to PUBLIC and create a public synonym leading to the temporary table. He would Toad to use the synonyms to run the Explain Plan.
This scenario is possible in Toad for Oracle, as it locates and uses the plan table synonym, however, TDA does not have this verification and hence it errors out to ORA-01031 error when using the Explain Plan, since it tries to create the plan table.
Enhancement request ST 59396 has been submitted to Development for consideration in a future release of Toad for Data Analysts.
In the connection window, there is an "Explain Plan Table" field from which user can use to select a specific existing plan table for running the Explain Plan.