Jul 27 2017

Oracle 12c R2 (12.2.0.1) RAC Installation Steps on Oracle Linux 7.3

Category: AdministrationFatih Acar @ 14:37

Oracle Real Application Clusters (Oracle RAC) is a clustered database infrastructure of Oracle Database based on a comprehensive high-availability stack that can be used as the foundation of a database cloud system as well as a shared infrastructure, ensuring high availability, scalability, and agility for any application. Oracle Real Application Cluster has been using with Oracle 9i version since in 2001. This feature provides software for clustering and high availability in Oracle database environments.

Top Benefits of Real Application Clusters (RAC)

  • Ability to spread CPU load across multiple servers
  • Continuous Availability / High Availability (HA)

– Protection from single instance failures

– Protection from single server failures

  • RAC can take advantage of larger SGA sizes than can be accommodated by a single instance commodity server
  • Scalability

 

 

 

Oracle RAC installation steps are a bit long. Firstly, you have to adjust system parameters of operating system on both node and create asm disks. After, you can start to install of grid infrastructure. You can create disk groups for DATA and FRA disk groups after install grid. Finally you can install Oracle RAC database on grid infrastructure and ASM disks. I divide the stages of installation four steps.

First Step : Configure Operation System

Continue reading “Oracle 12c R2 (12.2.0.1) RAC Installation Steps on Oracle Linux 7.3”

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Jun 16 2017

PostgreSQL 10 New Features

Category: AdministrationFatih Acar @ 15:51

PostgreSQL 10 has very good new features. In my opinion, mainly new features are Logical Replication, Improved Parallel Query, Scram Authentication, Declarative Partitioning.

Logical Replication :  PostgreSQL has had physical replication that often called streaming replication since version 9.0, but this requires replicating the entire database, cannot tolerate writes in any form on the standby server, and is useless for replicating across versions or database systems.  PostgreSQL has had logical decoding that basically change capture since version 9.4, which has been embraced with enthusiasm, but it could not be used for replication without an add-on of some sort.  PostgreSQL 10 adds logical replication which is very easy to configure and which works at table granularity, clearly a huge step forward.  It will copy the initial data for you and then keep it up to date after that.

Improved Parallel Query : While PostgreSQL 9.6 offers parallel query, this feature has been significantly improved in PostgreSQL 10, with new features like Parallel Bitmap Heap Scan, Parallel Index Scan, and others.  Speedups of 2-4 x are common with parallel query, and these enhancements should allow those speedups to happen for a wider variety of queries.

SCRAM Authentication :  PostgreSQL offers a remarkable variety of different authentication methods, including methods such as Kerberos, SSPI, and SSL certificate authentication, which are intended to be highly secure.  However, sometimes users just want to use passwords managed by the PostgreSQL server itself.  In existing releases, this can be done either using the passwordauthentication type, which just sends the user-supplied password over the wire, or via the md5authentication type, which sends a hashed and salted version of the password over the wire.  In the latter approach, stealing the hashed password from the database or sniffing it on the wire is equivalent to stealing the password itself, even if you can’t compute a preimage.  PostgreSQL 10 introduces scram authentication, specifically SCRAM-SHA-256, which is much more secure.  Neither the information which the server stores on disk nor the contents of an authentication exchange suffice for the server to impersonate the client.  Of course, the substitution of SHA-256 for MD5 is also a substantial improvement. One point to note is that, unless you are using libpq, you will not be able to use this feature unless your particular client driver has been updated with SCRAM support, so it may be a while before this feature is universally available.

Declarative Partitioning : In previous versions of PostgreSQL, PostgreSQL supported only table inheritance, which could be used to simulate table partitioning, but it was complicated to set up and the performance characteristics were not that great.  In PostgreSQL 10, it’s possible to do list or range partitioning using dedicated syntax, and INSERT performance has been greatly improved.

Also, you can look other new features from here.

 

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Apr 17 2017

Find And Delete Files Greater Than Given Size on Linux

Category: Linux & UnixFatih Acar @ 19:56

If you want to delete files which are greater than given size on Linux, you can use below examples by changing as your need.

Delete Files

Delete files which are size more than 2 MB. and type is jgp.

[root@testserver ~]# find /tmp/ -type f -size +2M -name “*.jpg” -exec rm -rf {} \;

Delete files which are size more than 2 MB low than 5 MB. and type is jpg.

[root@testserver ~]# find /tmp/ -type f -size +2M -size -5M -name “*.jpg” -exec rm -rf {} \;

Delete files which are size low than 10 MB. and type is zip.

[root@testserver ~]# find /tmp/ -type f -size -10M -name “*.zip” -exec rm -rf {} \;

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Tags: Linux Administration, System Administration


Mar 28 2017

Oracle 11g R2 Resize Redo Log Size on Data Guard and Primary Database

Category: Administration,Backup And Recovery,Errors and SolutionsFatih Acar @ 15:07

Sometimes, you may need to change redo log size to perform optimum size for performance. If you want to change redo log size of both standby side and primary side, you can use below commands.

Current Status Of Redo Logs

Primary Side


SQL> select group#,sum(bytes/1024/1024)"Size in MB" from v$log group by group#;
 
GROUP#     Size in MB
-------    ----------
1          50
2          50
3          50
 
SQL> select group#,sum(bytes/1024/1024)"Size in MB" from v$standby_log group by group#;
 
GROUP#   Size in MB
-------  ----------
 4       50
 5       50
 6       50
 7       50

Standby Side



SQL> select group#, sum(bytes/1024/1024)"Size in MB" from v$loggroup by group#;
 
GROUP# Size in MB
------ -------------
 1     50
 2     50
 3     50
 
SQL> select group#,sum(bytes/1024/1024)"Size in MB" from v$standby_log group by group#;
 
GROUP# Size in MB
------ ----------
 4     50
 5     50
 6     50
 7     50

Change Size Of Redo Logs

Auto File Management Disable on Standby Side


SQL> alter system set standby_file_management=manual

System altered.

Change Redo Log Size Of Primary Side
Continue reading “Oracle 11g R2 Resize Redo Log Size on Data Guard and Primary Database”

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Tags: Database Administration, Oracle Administration


Mar 28 2017

Oracle 11g R2 Open Data Guard Read Write Mode With Flashback Technology And Revert Restore Point

Category: Administration,Backup And RecoveryFatih Acar @ 13:34

You can use flashback technology on standby side. If you want to make application test on database, you can use data guard as read write mode temporarily with flashback technology. You can create a restore point on standby side then you can do any transaction on standby side to test or any other purpose. After you complete your operations on the standby side, you can revert to restore point and again connect to primary side and apply logs from primary side.

This feature can be use for application test operations.

Perform Flashback Steps

Standby Side


SQL> alter database recover managed standby database cancel;

Database altered.

SQL> alter database flashback on;

Database altered.

Note : Check recovery destination and size. You have to have recovery dest and size.

SQL> show parameter recovery

NAME				     TYPE	 VALUE
------------------------------------ ----------- ------------------------------
db_recovery_file_dest		     string	 /oracle/fra
db_recovery_file_dest_size	     big integer 10G
recovery_parallelism		     integer	 0

SQL> create restore point before_test guarantee flashback database;

Restore point created.

Primary Side


SQL> alter system archive log current;

System altered.

Note : Archive dest for standby log sync parameter set defer.

SQL> alter system set log_archive_dest_state_2=defer;

System altered.

Continue reading “Oracle 11g R2 Open Data Guard Read Write Mode With Flashback Technology And Revert Restore Point”

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Tags: Database Administration, Oracle Administration, Oracle Backup and Restore, Oracle Data Guard


Mar 28 2017

Oracle 11g R2 Data Guard Manual Switchover Steps

Category: Administration,Backup And RecoveryFatih Acar @ 09:47

You can use the same steps to switchover for single data guard or multiple data guard configuration.

Switchover operation will convert primary side to data guard and data guard to primary side.

You have to control listeners whether it is running before switchover steps.

Switchover Steps

Primary Side


SQL> alter system archive log current;

SQL> alter database commit to switchover to standby with session shutdown;

SQL> shutdown immediate;

SQL> startup mount;

Data Guard Side
Continue reading “Oracle 11g R2 Data Guard Manual Switchover Steps”

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Tags: Database Administration, Oracle Administration, Oracle Data Guard, Oracle Data Guard Switchover


Mar 27 2017

Oracle 11g R2 Multi Real Time Apply Data Guard Configuration Steps

Category: Administration,Backup And RecoveryFatih Acar @ 16:42

Oracle 11g R2 database supports multi standby database structure up to 30 standby databases. We can use remote destinations for real time apply standby structures with todays network technologies. If your remote destination network is not good, you can use archivelog apply for remote destination with some delay.

System informations are like below.

System Informations

PRIMARY DATABASE
VERSION : 11.2.0.3
IP : 192.168.9.129
SID : PRI
HOSTNAME : primary.localdomain

FIRST STANDBY DATABASE
VERSION : 11.2.0.3
IP : 192.168.9.130
SID : DR1
HOSTNAME : dr1.localdomain

SECOND STANDBY DATABASE
VERSION : 11.2.0.3
IP : 192.168.9.131
SID : DR2
HOSTNAME : dr2.localdomain
Continue reading “Oracle 11g R2 Multi Real Time Apply Data Guard Configuration Steps”

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Tags: Database Administration, Oracle Administration


Mar 21 2017

Oracle 11g R2 Cascade Standby Data Guard Installation and Configuration Steps

Category: Administration,Backup And RecoveryFatih Acar @ 16:32

Oracle 11g R2 database supports cascade standby database structure. If you are using RAC on primary side, your database version has to be least 11.2.0.2 to support cascade standby structure. You can use to reduce the load on your primary database with using cascade standby database structure.

Primary database redo is written to the standby redo log as it is received at a cascading standby database. The redo is not immediately cascaded however. It is cascaded after the standby redo log file that it was written to has been archived locally. A cascaded destination will therefore always have a greater redo transport lag, with respect to the primary database, than the cascading standby database.

Restrictions

  • Cascading Structure is not supported by Data Guard Broker.
  • To use Oracle RAC on primary side, you have to use least 11.2.0.2 verion.
  • Cascaded standby database do not support Real Time Apply

I will configure cascade standby database structure like below schema.

System Informations

PRIMARY DATABASE
VERSION : 11.2.0.3
IP : 192.168.9.129
SID : PRI
HOSTNAME : primary.localdomain

Continue reading “Oracle 11g R2 Cascade Standby Data Guard Installation and Configuration Steps”

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Tags: Database Administration, Oracle Administration


Mar 03 2017

Oracle 12c R2 Downloadable Now

Category: AdministrationFatih Acar @ 16:27

You can download Oracle 12c R2 database now. Only Linux x64 and Solaris Operation Systems supported for now.

You can download with below link;

http://www.oracle.com/technetwork/database/enterprise-edition/downloads/index.html

Also you can find new features about of Oracle 12c R2 with below links;

https://docs.oracle.com/database/122/

https://blogs.oracle.com/sql/entry/12_things_developers_will_love

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Tags: Oracle 12c, Oracle Administration


Feb 06 2017

Configure Default full-text language Parameter Server Configuration in SQL Server 2016

Category: AdministrationFatih Acar @ 15:33

You can change default full-text language server configuration option in SQL Server 2016 by using SQL Server Management Studio or Transact-SQL. default full-text language option specifies a default language value for full-text indexes. Linguistic analysis is performed on all data that is full-text indexed and is dependent on the language of the data. The default value of this option is the language of the server. For a localized version of SQL Server, SQL Server Setup sets the default full-text language option to the language of the server if an appropriate match exists. For a non-localized version of SQL Server, the default full-text language option is English.

Change Parameter With SQL Server Management Studio

  1. Open Object Explorer, right-click a server and select Properties.
  2. Click Advanced Step.
  3. Under Miscellaneous, use Default Full Text Language to specify a default language value for full-text indexed columns.

Change Parameter With Transact-SQL

I will change option to 1055 that is Turkish language code. You can see LCID codes of language with below query. You can change with below queries.

select * from sys.fulltext_languages;

USE ;
GO
EXEC sp_configure ‘show advanced options’, 1 ;
GO
RECONFIGURE
GO
EXEC sp_configure ‘default full-text language’, 1055 ;
GO
RECONFIGURE
GO

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Tags: MsSQL Server, SQL Server Administration


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