Is DB schema audit logging on BPM schema table enabled by BPMS installer ?

Issue

We are on BPM 6.4.0 version. Recently we had a critical performance issue across all applications. While reviewing the ORACLE session DBAs noted that we have enabled audit for delete statement on WorkItemInfo table. This table is heavily used considering the amount of data being processed and they mentioned that since audit is enabled it is talking a lot of oracle memory and causing delays in processing. we reviewed other tables in the BPM schema and I see audit is enabled for most of the tables. I would like to understand if the audit option is enabled on all tables in this schema as part of the installation and it is required or it may been enabled by us somehow ?