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AWR: Multitenant-Specific Initialization Parameters

By default, the database engine automatically takes snapshots in the root container only. Such snapshots cover the root container as well as all open PDBs belonging to it. From version 12.2 onward, you can control whether the database engine automatically takes also PDB-level snapshots through the dynamic initialization parameter AWR_PDB_AUTOFLUSH_ENABLED. In case you want to […]

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 the PL/SQL Packages and Types Reference, is the following: The […]

MIN/MAX Optimization and Asynchronous Global Index Maintenance

In this short post I would like to point out a non-obvious issue that one of my customers recently hit. On the one hand, it’s a typical case where the query optimizer generates a different (suboptimal) execution plan even though nothing relevant (of course, at first sight only) was changed. On the other hand, in […]

Observations About the Scalability of Data Loads in ADWC

In the last days, I am running a number of tests based on the TPC-DS benchmark against Oracle’s Autonomous Data Warehouse Cloud service (ADWC). One of the first thing I did is of course to create the TPC-DS schema and populate it. The aim of this blog post is to share some observations related to […]

Which Privileges Are Required to Use the ADWC Service Console?

The Autonomous Data Warehouse Cloud (ADWC) service provides a Service Console that can be used to monitor the service activity and to carry out a small number of administration tasks (e.g. changing some resource management rules). The documentation specifically says to use the ADMIN user to login. But, actually, any unlocked database user having the […]

DBMS_CLOUD Package – A Reference Guide

The Appendix A of the Using Oracle Autonomous Data Warehouse Cloud guide describes the DBMS_CLOUD package. Unfortunately, it documents only a subset of the subroutines. And, for some of them, the description could also be enhanced. Therefore, while I was testing all the subroutines the DBMS_CLOUD package provides, I took a number of notes. By […]