Problem: Audits getting slower over time but nothing has changed.
Solution: Re-index your database audit tables.
At UCI, we use In-progress classes and update them on a daily basis. With 30,000 students in 
DW, a lot of database records get changed, thus database indexing becomes overwhelming.
DW and Oracle doesn't know when or how to 
re index the audit tables so it would be wise to add this to your quarterly maintenance. If I don't re index, our audits take twice as long to process.
The tables - 
dap_audit_
dtl, 
dap_
audtree_
dtlThe indexes - for 
dap_audit_
dtl: (via 
xsql, select index_name from 
dba_ind_columns where table_name='
DAP_AUDIT_
DTL';)
for 
dap_
audtree_
dtl: (via 
xsql, select index_name from 
dba_ind_columns where table_name='
DAP_
AUDTREE_
DTL';)

Two options in 
re indexing:
A) Simply rebuild the index in 
xsql:
- login to the account.
- login to xsql.
- type the rebuild index command for each of the indexes:  "alter index DAP_AUDIT_DTL_A rebuild unrecoverable;" 
- Do this for each index. (DAP_AUDIT_DTL_A, DAP_AUDIT_DTL_B... etc.)
B) Rebuild the index in a new 
tablespace (recommended for very large 
FTE's):
- Same as above but add the tablespace command: "alter index DAP_AUDIT_DTL_A rebuild tablespace  (tablespace name) unrecoverable;"
Option B recommended by Oracle 
DBA for very large tables because instead of using temp space to create the new indexes, it just builds them in the new 
tablespace.  Plus this is a much faster process.
Our I alternate between two 
tablespaces that are 6 GB large just for 
dap audit indexes. Yes, that is very large. Our tablespaces just for audits are 20 GB.
** Please consult with your IT staff at your site before experimenting with this. ***