AWR Flush Levels
From version 12.1.0.2 onward, for taking AWR snapshots, you have the choice between four AWR flush levels: BESTFIT, LITE, TYPICAL and ALL. If you check the Oracle Database documentation, you won’t find much information about the difference between them. The best you will find, in…
CDB Views and Query Optimizer Cardinality Estimations
Today I faced a performance problem caused by a bad cardinality estimation involving a CDB view in a 12.1.0.2 multitenant environment. While solving the problem I did a number of observations that I try to summarize in this blog post. First of all, when checking…