DBCA 12.2 does not update /etc/oratab in GI / RAC

DBCA 12.2 does not update /etc/oratab in GI / RACInteresting things happen. And I learned (credits to Arun Gupta and others) that there is a change in Oracle Database 12.2 environments I wasn’t aware: The DBCA 12.2 does not update /etc/oratab in GI / RAC environments. Let me give you some extra information and hints on this topic as it may cause some strange situations.… [Read More]

Alert.log: New timestamp format in Oracle 12.2

Timestamp Format Change

There’s an interesting change in the alert.log since Oracle Database 12.2.0.1: The format of the timestamps has changed.

If you compare the timestamps in Oracle 12.1 vs Oracle 12.2 you’ll recognize the change immediately:

Oracle 12.1 Oracle 12.2
Wed Feb 08 15:39:29 2017
Database mounted in Exclusive Mode
Lost write protection disabled
Completed: ALTER DATABASE   MOUNT
Wed Feb 08 15:39:29 2017
ALTER DATABASE OPEN
Wed Feb 08 15:39:29 2017
Ping without log force is disabled.
[Read More]

PGA_AGGREGATE_LIMIT enforces default since Oracle Database 12.2.0.1

The init.ora/spfile parameter PGA_AGGREGATE_LIMIT got introduced in Oracle Database 12.1.0.1.

As per documentation in Oracle Database 12.1 it got defined as:

PGA_AGGREGATE_LIMIT specifies a limit on the aggregate PGA memory consumed by the instance.“.

Furthermore the algorithm for its setting got described as:

By default, PGA_AGGREGATE_LIMIT is set to the greater of 2 GB, 200% of PGA_AGGREGATE_TARGET, and 3 MB times the PROCESSES parameter.[Read More]

Having some fun with SEC_CASE_SENSITIVE_LOGON and ORA-1017

The init.ora/spfile parameter SEC_CASE_SENSITIVE_LOGON got deprecated since Oracle Database 12.1.0.1. This means, we don’t do any further developments to it, you shouldn’t change it from its default TRUE – and if you still do you’ll receive a nice warning during STARTUP of your database:

SQL> alter system set sec_case_sensitive_logon=false scope=spfile;

System altered.
[Read More]

Global Temporary Tables – Change in Oracle 12c

A few weeks back I was copied on an email conversation about a important change with Global Temporary Tables (GTT) in Oracle Database 12c.

Something you need to be aware of when using GTTs in Oracle Database 12.1.0.2:
Prior to this release GTTs shared statistics between sessions. Statistics were SHARED between different sessions.… [Read More]

New in Oracle 12c: _optimizer_gather_stats_on_load

Received an email from Roy last night with some performance issues a customer in the US encountered recently during their upgrade testing.

One issue the customer encountered has to do with tons of parallel slaves creating a massive noise on the system when they are doing a CTAS (Create Table As Select) – and the same thing happens with an IAS (Insert Append Select).… [Read More]