Question: We have a specific table that has a lot of activity and it creates a lot of change records. The consequence is that the flashback data only goes back a couple of days. That is OK for many cases but it would be beneficial to have access to more historical data.

We would like to either restrict logging on that table. Or disable it completely. I imagine that we may be able to do this by tablespace, I just have not found much on how to make these changes.

Answer: 
You can declare table as NOLOGGING. Then some of the DML and DDL operations will not be recorded in redo logs.

**[Oracle logging\_clause](http://docs.oracle.com/cd/E11882_01/server.112/e26088/clauses005.htm#i999782)**

Of course this has many caveats:

* if you have many NOLOGGING operations basically you won't be able to flashback or restore the table
* UPDATE or DELETE operations are logged in any case
* only direct path INSERTS can skip logging. But that means that such INSERT will not reuse empty space in table segment and will extend it every time you do such INSERT.

In my experience in some situations one can save a lot of redo/archivelog space using NOLOGGING but you have to adapt your code to it.
In addition to miracle173's good answer, here is a thought on limiting the undo impact of the table that while workable probably isn't advisable. 

Undo on a table (and therefore the ability to do flashback queries) is removed when a DDL operation occurs for a table. So, if there is a quiet time on the table (during the night for example) you could alter the table (such as by adding a column that you immediately remove). As long as no in progress transaction is occurring on the table this should allow the undo associated with the table to be overwritten therefore allowing more undo from other tables.

No, I don't really think you should try this.