Tuesday, 31 October 2017

DBMS_COMPRESSION Enhancements in Oracle Database 12c

The DBMS_COMPRESSION package was introduced in Oracle 11gR2. Oracle Database 12c includes a number of enhancements to the DBMS_COMPRESSION package.

◉ Setup


The examples in this article use the table defined below.

Monday, 30 October 2017

What is difference between primary key and unique key in table - SQL database

Primary key vs unique key in SQL


The primary key and unique key are two important concepts in a relational database and used to uniquely identify a row in a table. Both primary key and unique key can identify a row uniquely but there is some subtle difference between them which we will see in this article. In fact, primary key vs unique is a popular SQL interview questions along with classics like truncate vs delete and  How to manage transaction in a database, mostly asked to fresher and 2 to 3 years experience guys in any programming language. SQL is not just limited to any DBA or PLSQL developer but its an important skill even for Java programmer and you can expect SQL interview question even in many Java interviews.

Saturday, 28 October 2017

How to connect Eclipse to Oracle database - Step by Step Guide

Though, I prefer Toad or Oracle SQL Developer tool to connect Oracle database, sometimes it's useful to directly connect Eclipse to Oracle using JDBC using its Data Source Explorer view. This means you can view data, run SQL queries to the Oracle database right from your Eclipse window. This will save a lot of time wasted during switching between Toad and Eclipse or Oracle SQL Developer and Eclipse. Eclipse also allow you to view Execution plan in both text and Graphical mode, which you can use to troubleshoot performance of your SQL queries. In this article, I'll tell you steps to connect Eclipse to Oracle database. Since Eclipse uses Java to connect to Oracle database, it asks for JDBC driver information. Since connecting using thin Oracle JDBC driver is much easier, as you just need to drop a JAR file in the classpath, we will be using JDBC thin driver to connect Oracle from Eclipse. Depending upon your Oracle version e.g. Oracle 10g or Oracle 11g you need to download Oracle JDBC thin driver e.g. ojdbc14.jar file. Just download this JAR file and configure it on Eclipse IDE. Enter username, password and sid and you are ready to execute SQL query to Oracle database from Eclipse.

Friday, 27 October 2017

Oracle Enterprise Manager Cloud Control 12c Post-Installation Setup Tasks

◉ Setup Software Library


Create a directory to use as the software library.

$ mkdir -p /u01/app/oracle/oms12cr2/software_library

Navigate to the "Software Library: Administration" screen using the menu at the top-right of the screen (Setup > Provisioning and Patching > Software Library).

Thursday, 26 October 2017

Oracle Enterprise Manager Cloud Control 12c Release 4 Installation on Oracle Linux 5.9 and 6.5

Enterprise Manager Cloud Control is the new name for what was previously know as Enterprise Manager Grid Control. Depending on the source of the material, you may still see the product described as Grid Control. This article describes the installation of Oracle Enterprise Manager Cloud Control 12c Release 4 on Oracle Linux 5.9 and 6.5. (x86_64).

Wednesday, 25 October 2017

Oracle Enterprise Manager Cloud Control 12c Release 3 Installation on Oracle Linux 5.9 and 6.4

Enterprise Manager Cloud Control is the new name for what was previously know as Enterprise Manager Grid Control. Depending on the source of the material, you may still see the product described as Grid Control. This article describes the installation of Oracle Enterprise Manager Cloud Control 12c Release 3 on Oracle Linux 5.9 and 6.4. (x86_64). This is the first Cloud Control release capable of monitoring the Oracle 12c database.

Tuesday, 24 October 2017

Oracle Enterprise Manager Cloud Control 12c Release 2 Installation on Oracle Linux 5.8 and 6.3

Enterprise Manager Cloud Control is the new name for what was previously know as Enterprise Manager Grid Control. Depending on the source of the material, you may still see the product described as Grid Control. This article describes the installation of Oracle Enterprise Manager Cloud Control 12c Release 2 on Oracle Linux 5.8 and 6.3. (x86_64).

Tuesday, 17 October 2017

Oracle Enterprise Manager Cloud Control 12c Release 1 Installation on Oracle Linux 5.7 and 6.1

Enterprise Manager Cloud Control is the new name for what was previously know as Enterprise Manager Grid Control. Depending on the source of the material, you may still see the product described as Grid Control. This article describes the installation of Oracle Enterprise Manager Cloud Control 12c Release 1 on Oracle Linux 5.7 and 6.1. (x86_64).

Monday, 16 October 2017

MySQL 8.0 RC1 Now Available

Oracle has announced the availability of the first release candidate of MySQL 8.0, which focuses on making MySQL better for modern apps.

The 8.0 also marks a departure from the 5.x numbering series, which has been used since 2005. Skipping 6.x and 7.x was intentional to avoid confusion with a previous alpha release and MySQL Cluster, and also to communicate the depth of some of the core changes, writes Tocker.

Thursday, 12 October 2017

Azure SQL Database Long-Term Backup Retention

Azure SQL Database provides a number of benefits that leverage resiliency and redundancy built into the underlying cloud infrastructure. You can take advantage of this functionality in order to perform backup, restore, and failover tasks, which help you recover from human errors, service outages, or even regional disasters. We have already described some of the corresponding features on this forum, including Point-in-Time Restore as well as Geo-Restore and Active Geo-Replication. Each one of them is an integral part of the Azure SQL Database service offering, regardless of the pricing tier. However, it is important to note that automatic backups created by Point-in-Time Restore, while convenient, have a relatively limited retention period (up to 35 days, with the Premium pricing tier). While this typically suffices to accommodate scenarios that involve restores due to an accidental data loss, it is not sufficient to satisfy archival and compliance requirements of an overwhelming majority of customers. To remediate this shortcoming, you have the option of implementing long-term backup retention of Azure SQL Database.

Wednesday, 11 October 2017

A Recent Innovation in NoSQL Data Modeling: Forward and Reverse Engineering Combined

Many organizations would like to develop and incorporate a NoSQL data model in their existing architectures, and to hire staff with Data Modeling skills. Unfortunately, there is a significant lack of data modelers with NoSQL experience, and reliable NoSQL Data Modeling tools are only just beginning to emerge into the market. The shortage of experienced NoSQL data modelers, combined with the scarcity of appropriate tools and delayed projects, can stunt a company’s growth.

Tuesday, 10 October 2017

An Introduction to Control Center Personalities in DB2 Universal Database

If you come from a Windows background, you are likely to leverage a graphical user interface (GUI) to perform most of the management tasks for your environment, including managing your IBM DB2 Universal Database (DB2 UDB) server. The Control Center is the GUI tool that provides database administrators (DBAs) with a central location from which to perform DB2-related administration tasks, and more.

Monday, 9 October 2017

Azure Azure SQL Database Long-Term Backup Retention Long-Term Backup Retention

Azure SQL Database provides a number of benefits that leverage resiliency and redundancy built into the underlying cloud infrastructure. You can take advantage of this functionality in order to perform backup, restore, and failover tasks, which help you recover from human errors, service outages, or even regional disasters. We have already described some of the corresponding features on this forum, including Point-in-Time Restore as well as Geo-Restore and Active Geo-Replication. Each one of them is an integral part of the Azure SQL Database service offering, regardless of the pricing tier. However, it is important to note that automatic backups created by Point-in-Time Restore, while convenient, have a relatively limited retention period (up to 35 days, with the Premium pricing tier). While this typically suffices to accommodate scenarios that involve restores due to an accidental data loss, it is not sufficient to satisfy archival and compliance requirements of an overwhelming majority of customers. To remediate this shortcoming, you have the option of implementing long-term backup retention of Azure SQL Database. Note that this functionality is in public preview at the time of authoring of this article.

Friday, 6 October 2017

Updating Production Environments to Feed a Big Data Application

Your big data application needs regular extracts from your production systems. While many best practices exist for big data extract, transform and load (ETL) processes, we sometimes forget that these data-intensive procedures can affect the operational environment’s performance.


Big Data Application Resource Usage


Today’s big data applications are scaling up and out. This involves adding more CPU power, more memory, and more system resources. IT staff are also upgrading the hybrid hardware and software appliances used for big data information storage and execution of business analytics.

Thursday, 5 October 2017

Oracle Database to SQL Server Comparisons

One of the initial obstacles a database administrator encounters is learning where features of his/her system live or reside on a less familiar system. Steve Callan approaches this feature comparison by taking SQL Server and mapping its features back into Oracle.

No, this isn’t one of those “why my RDBMS is better than your RDBMS” comparisons. One of the initial stumbling blocks a DBA on one system encounters is learning or trying to figure out where features of your system live or reside on the other (less familiar to you) system. Let’s approach this feature comparison by taking SQL Server and mapping its features back into Oracle. By way of time and constraints, this comparison will not be 100% inclusive of either system, but it will show (as much as possible) the SQL Server to Oracle mapping using what you can see in SQL Server Management Studio (SSMS).

Wednesday, 4 October 2017

Table types in MySQL: InnoDB tables

InnoDB is a storage engine for the database management system MySQL. MySQL 5.5 and later use it by default. It provides the standard ACID-compliant transaction features, along with foreign key support (Declarative Referential Integrity).

Tuesday, 3 October 2017

9 New Features with SQL Server 2017

9 New Features with SQL Server 2017


Microsoft has added a ton of new features in SQL Server 2017, including expanded operating system support, Graph database capability, Python support, and more. Read on to learn about nine of these new features.