Comparing database 12cR1 release 12.1.0.2 to 12cR2 release 12.2.0.0.3, I see these new parameters: adg_imc_enabled TRUE Enable IMC support on ADG allow_global_dblinks FALSE LDAP lookup for DBLINKS allow_group_access_to_sga FALSE Allow read access for SGA to users of Oracle owner group …
I am fascinated by what I call “equal SQL”: statements that are equivalent, in that they deliver the same result but may have hugely different performance characteristics. Here’s a little case study. Consider this example, working in the OE demonstration …
HCC is available only on Oracle supplied storage, such as a ZFS storage appliance or (as in this case) an Exadata engineered system. Furthermore, it occurs only for direct loads: in my examples, using CTAS. This is the script I’m …