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 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
Wed Feb 08 15:39:29 2017
Wed Feb 08 15:39:29 2017
Ping without log force is disabled.
[Read More]

PGA_AGGREGATE_LIMIT enforces default since Oracle Database

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

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 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
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]