Month: September 2018

Database, SQL | PLSQL

Oracle Top Growing Segments

This is the second post of a serie. First one here.

Now that you already have an idea regarding the size of the database top segments (first post), you might want to check the top growing segments, considering a specified number of days back.

You probably used some AWR information in past or generated an AWR report, at least. But if this is still new to you, AWR stands for Automatic Workload Repository. AWR is a built-in repository, used to collect, process, and maintain performance statistics for problem detection and self-tuning purposes. This gathered data is stored both in memory and in the database, and is displayed in both reports and views.

For additional information, you can check this official doc here.

We are going to use some AWR views:
– dba_hist_seg_stat: historical information captured from V$SEGSTAT about segment-level statistics.
– dba_hist_seg_stat_obj: names of the segments captured in the workload repository.

More“Oracle Top Growing Segments”

Database, SQL | PLSQL

Disable/Enable Maintenance Jobs

Hi all!
A couple days ago a client asked me assistance to disable all the maintenance jobs on DB to run a critical process.

First considerations: We could just disable window changing, once the jobs are related to windows, and Resource Manager Plans use to be as well. However, to answer the question directly:

# To disable/enable all maintenance jobs in from/for all windows:

EXEC DBMS_AUTO_TASK_ADMIN.disable;
EXEC DBMS_AUTO_TASK_ADMIN.enable;

# And to disable/enable specific maintenance jobs from/for all windows:

exec DBMS_AUTO_TASK_ADMIN.DISABLE('AUTO OPTIMIZER STATS COLLECTION',NULL, NULL);
exec DBMS_AUTO_TASK_ADMIN.DISABLE('AUTO SPACE ADVISOR',NULL, NULL);
exec DBMS_AUTO_TASK_ADMIN.DISABLE('SQL TUNING ADVISOR', NULL, NULL);

exec DBMS_AUTO_TASK_ADMIN.ENABLE('AUTO OPTIMIZER STATS COLLECTION',NULL, NULL);
exec DBMS_AUTO_TASK_ADMIN.ENABLE('AUTO SPACE ADVISOR',NULL, NULL);
exec DBMS_AUTO_TASK_ADMIN.ENABLE('SQL TUNING ADVISOR', NULL, NULL);

More information and details about it can be taken from here: https://docs.oracle.com/cd/E11882_01/server.112/e25494/tasks.htm#ADMIN11836

Hope it helps. Cheers!

Database, RAC | Data Guard

Exadata Compute Node Not Starting after a long Period…

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Well,
After a long time on a graceful reboot, the compute node was simply not starting… What do to?
The best is:

1. Connect to ILOM Console:

Go to: Host Management –> Power control –> select Power Cycle in drop down list.

2. Connect to ILOM Server start SP console:
You may do it from another node, of course.

[root@grepora02 ~]# ssh root@grepora01-ilom Password:

Oracle(R) Integrated Lights Out Manager

Version 3.2.9.23 r116695

Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.

Warning: HTTPS certificate is set to factory default.

Hostname: grepora01-ilom

-> start /SP/console Are you sure you want to start /SP/console (y/n)? y

And, if not, as always, create a SR and follow with Oracle is the best way to go…

Hope it helps!

SQL | PLSQL

PL/SQL Generalized Invocation

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Did you know we have that since 11g? The generalized invocation allows a subtype to invoke a method of a parent type (supertype) using the following syntax:

(SELF AS supertype_name).method_name

Check the example below to understand it. First, creating original type:

CREATE OR REPLACE TYPE type_test AS OBJECT (MEMBER FUNCTION return_text RETURN VARCHAR2) NOT FINAL;
/

CREATE OR REPLACE TYPE BODY type_test AS
MEMBER FUNCTION return_text RETURN VARCHAR2 IS
BEGIN RETURN 'This is the original text.'; END;
END;
/

And now creating a subtype of this object, which adds a new attribute and method as well as overriding the member’s function.

CREATE OR REPLACE TYPE subtype_test UNDER type_test (OVERRIDING MEMBER FUNCTION return_text RETURN VARCHAR2);
/

CREATE OR REPLACE TYPE BODY subtype_test AS
OVERRIDING MEMBER FUNCTION return_text RETURN VARCHAR2 IS
BEGIN RETURN (self AS type_test).return_text || ' This is an additional subtype text.'; END;
END;
/

And when calling:

SET SERVEROUTPUT ON
DECLARE
my_subtype subtype_test;
BEGIN
DBMS_OUTPUT.put_line(my_subtype.show_attributes);
END;
/
This is the original text. This is an additional subtype text.

A type can invoke the member functions of any parent type in this way, regardless of the depth of the inheritance.

Pretty nice, right?
Cheers!

Cloud Services, Cloud Services | Exadata | Linux, Database

Creating a Free Oracle Database at AWS

Have you ever heard about Amazon RDS?

Amazon RDS is a Relational Database cloud based service, which intends to help you to automate administrative tasks like hardware provisioning, database creation, backups, etc. Currently six database engines are available under this service: Oracle Database, Microsoft SQL Server, Amazon Aurora, PostgreSQL, MySQL and MariaDB.

This post provides a quick step-by-step on how to create your first Oracle Database RDS.

Requirements:
– Have an Amazon AWS account. If you don’t have one, don’t panic! You can still create one at: https://portal.aws.amazon.com/gp/aws/developer/registration/index.html

Now, how to create a RDS? Here it goes:

More“Creating a Free Oracle Database at AWS”

Database, Enterprise Manager

OEM after a Maintenance: A memory component is suspected of causing a fault with a 100% certainty. Component Name : % Fault class : fault.memory.intel.dimm_ce

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Hi all!
So, I had this message from a memory component in my Exadata:

Message=A memory component is suspected of causing a fault with a 100% certainty. Component Name : /SYS/MB/P0/D3 Fault class : fault.memory.intel.dimm_ce

But this was right after a maintenance on server. Checking on ILOM:

-> show /SYS/MB/P0/D3

 /SYS/MB/P0/D3
    Targets:
        PRSNT
        SERVICE

    Properties:
        type = DIMM
        ipmi_name = MB/P0/D3
        fru_name = 16384MB DDR4 SDRAM DIMM
        fru_manufacturer = Samsung
        fru_part_number = %
        fru_rev_level = 01
        fru_serial_number = %
        fault_state = OK
        clear_fault_action = (none)

Checking on CellCLI alert history:

CellCLI> list alerthistory detail

	 name:                   13_1
	 alertDescription:       "A memory component suspected of causing a fault"
	 alertMessage:           "A memory component is suspected of causing a fault with a 100% certainty.  Component Name : /SYS/MB/P0/D3  Fault class    : fault.memory.intel.dimm_ce  Fault message  : http://support.oracle.com/msg/SPX86A-8002-XM"
	 alertSequenceID:        13
	 alertShortName:         Hardware
	 alertType:              Stateful
	 beginTime:              %
	 endTime:                %
	 examinedBy:             
	 metricObjectName:       /SYS/MB/P0/D3_FAULT
	 notificationState:      1
	 sequenceBeginTime:      %
	 severity:               critical
	 alertAction:            "For additional information, please refer to http://support.oracle.com/msg/SPX86A-8002-XM Automatic Service Request has been notified with Unique Identifier: %.  Diagnostic package is attached. It is also accessible at % It will be retained on the storage server for 7 days. If the diagnostic package has expired, then it can be re-created at %"

Hm… Let’s read the MOS: SPX86A-8002-XM – Memory Correctable ECC (Doc ID 1615285.1)

“Suggested Action for System Administrator

Replace the faulty memory DIMM at the earliest possible convenience.”

Hmm… But as I said, this was right after a maintenance on server, what if this is related?
Ok, some additional piece of information:

-> version 
SP firmware 3.2.9.23 
SP firmware build number: 116695 
SP firmware date: Thu Mar 30 11:38:01 CST 2017 
SP filesystem version: 0.2.10

At the current firmware level of SP firmware 3.2.9.23 the memory correctable error threshold limit for DIMM replacement is 240 CEs in a 72 hrs period.

So, the suggestion is:
– Clear all the error messages after complete the maintenance and lets check if the threshold is reached again. If so, we may need to really replace it.

How to do it? Easy:

ssh root@grepora01-ilom
-> show /SYS/MB/P0/D3
Expected:
[...]
fault_state = Faulted
[..]
-> set /SYS/MB/P0/D3 clear_fault_action=true
Are you sure you want to clear /SYS/MB/P0/D3 (y/n)? y
-> show /SYS/MB/P0/D3
[Expected]
 /SYS/MB/P0/D3
    Targets:
        PRSNT
        SERVICE
Properties:
type = DIMM
ipmi_name = MB/P0/D3
fru_name = 16384MB DDR4 SDRAM DIMM
fru_manufacturer = Samsung
fru_part_number = %
fru_rev_level = 01
fru_serial_number = %
 fault_state = OK
clear_fault_action = (none)

Hope it helps!
Cheers!

Community, Events

2nd GUORS Meeting 2018: Feedback

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Hey all!

Quick one: Just passing by again to thank for the event organization to bring my same and for the attendees to ask me there again! 🙂

It’s always good to participate on a local events and meet so awesome people that are always around but we still don’t see very often.

For the ones looking for my slides, find always my updated slides here.

Cheers!

Database, GoldenGate

Oracle Streams: Adding a Table to Streams Replication

 ,

Feel old yet?
Don’t worry, we all know that there are still companies using Streams. So, here goes a quick manual for a regular activity: Add a new table to replication using SYS.DBMS_STREAMS_ADM.

For this, assume the following:

STREAMS SETUP OWNER => streams_adm
CAPTURE PROCESS => str_capture
APPLY_PROCESS => str_apply
SOURCE DATABASE TABLE OWNER => TBLOWNER
TARGET DATABASE TABLE OWNER => TBLOWNER_DEST

The high level steps to add table to streams are as follows:

1. Stop streams CAPTURE
2. Create the table on the target database
3. Configure the CAPTURE process
4. Add a rule to the APPLY process
5. Instantiate the new object
6. Create constraints and indexes
7. Restart streams CAPTURE and APPLY

Let’s detail them:

More“Oracle Streams: Adding a Table to Streams Replication”

Community, Events

2nd GUORS Meeting – 2018

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Hello all!

Just passing by to remember you about the next GUORS Meeting to take place tomorrow!
Best news? It’s all free. Come and let’s discuss a bit about Oracle technology!

flyer

Confirm your presence!

Date:
12/Sep/2018

Hour:
13:15 – 18:00 BRT

Place:
Auditório Talento Empreendedor – Tecnopuc Predio 96I

Agenda:

Start End What
13:15 13:45 Credenciamento – Público Externo
14:00 15:30 Oracle Apex 18 – New Features – Guilherme Solon da Costa – BEG
15:30 16:00 Break
16:00 17:30 Oracle Database Migration and Consolidation Techniques – Matheus Boesing
17:30 17:45 Encerramento

 

See you there!

Database, SQL | PLSQL

PLSQL: Working with NULLs and Function NHT_VALUE

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Did you know this function?

NTH_VALUE returns the result of expression on value of the nth row in the window defined by the analytic clause. The returned value has the data type of the expression. RESPECT NULLS or IGNORE clauses can be used to determine whether null values of expression are included in or eliminated from the calculation. The default is RESPECT NULLS. Also clauses FROM FIRST or FROM LAST determines whether the calculation begins at the first or last row of the window. The default is FROM FIRST.

The function returns NULL if the data source window has fewer than n rows. If n is null, then the function returns an error.

Example:

SELECT prod_id, channel_id, MIN(amount_sold),
    NTH_VALUE(MIN(amount_sold), 2) OVER (PARTITION BY prod_id ORDER BY channel_id
    ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING) nv
  FROM sales
  WHERE prod_id BETWEEN 13 and 16
  GROUP BY prod_id, channel_id;

   PROD_ID CHANNEL_ID MIN(AMOUNT_SOLD)         NV
---------- ---------- ---------------- ----------
        13          2           907.34      906.2
        13          3            906.2      906.2
        13          4           842.21      906.2
        14          2          1015.94    1036.72
        14          3          1036.72    1036.72
        14          4           935.79    1036.72
        15          2           871.19     871.19
        15          3           871.19     871.19
        15          4           871.19     871.19
        16          2           266.84     266.84
        16          3           266.84     266.84
        16          4           266.84     266.84
        16          9            11.99     266.84

 

For more information and examples, check: https://docs.oracle.com/cloud/latest/db112/SQLRF/functions114.htm#SQLRF30031

Cheers!