Frequently asked questions

We are an Oracle House. We are looking at an alternative to Oracle to reduce our costs. How easy is it to train our Oracle DBAs on PostgreSQL and Postgres Plus?

If you you are looking for a cost-effective alternative to Oracle then Postgres Plus Advanced Server (PPAS) from EnterpriseDB will be a very good choice for you. The application migration ​and re-training cost for resources is significantly reduced due to the Oracle Compatibility Layer present in PPAS.

Is it possible to achieve a high availability DB cluster using Postgres? Does Postgres support other recovery features e.g. DR Setup, Backup and PITR?

Yes, it’s possible to do so by using the replication feature of Postgres. PostgreSQL supports all kinds of recovery features using archive, logical, physical backups and point-in-time recovery.

Is it possible to migrate from RDBMS to MongoDB?

Yes, you can migrate from RDBMS e.g. Oracle to MongoDB. Please see the resources for more details (​

We are using CentOS and would like to know what benefits we would get by moving to RHEL

​There are many benefits of moving from CentOS to a supported platform such as RHEL, and peace of mind is one of them. You have a commercial entity behind you always with an assurance of fixing things when you need support. Besides Red Hat Enterprise Linux goes through more rigorous testing before it is released and hence the product is much more stable. Access to Red Hat discussion forums, knowledge base and packages are few of the many other benefits of Commercially Supported Enterprise Open Source.

How different is NGINX from other Web servers e.g Apache?

NGINX has a modular, event-driven, asynchronous, single-threaded architecture that scales extremely well on generic server hardware and across multi-processor systems. NGINX uses all of the underlying power of modern operating systems like Linux to optimize the usage of memory, CPU and network, and extract the maximum performance out of a physical or virtual server. The result is NGINX can handle 100s/ 1000s of concurrent connections in a very efficient manner with less CPU and RAM consumed.

Can the complete cluster be backed up?

Yes the complete cluster can be backed up by taking a physical backup {we can have links here} or by using pg_dumpall {we can have links here} to take a logical backup. One can also devise a custom script to backup individual databases in more optimal way one-by-one. If you would like us to help you identify best backup strategy and implement that, then please checkout our pgBackup Assist offerings or email us at with pgBackup Assist in subject line.

Is there a tool to upgrade the version in postgres?

Yes. There is pg_upgrade tool which is used to migrate to the latest postgreSQL versions without any issues as there is a good binary compatibility between the versions. To read more about pg_upgrade click here. Also video from Ashnik would help you upgrading to 9.3 from older versions, click here.

Are there any tools for replication in PostgreSQL?

Yes, there is a built-in binary log based replication for the whole cluster. It has 2 variants- log shipping and streaming replication. To know more about Streaming Replication you may want to check out our video blogs on streaming replication setup here and latest replication related features in v9.4 here. There are other tools e.g. slony and EnterpriseDB’s xDB Replication To know more about various HA and DR options in Postgres please checkout our slideshare resource here.

How easy is it migrate an Oracle Database to Postgres Plus? Is there a long down time involved in such migrations?

Ease of migration is purely dependent on the application schema, database access to application and application code. But by carefully choosing an application as migration candidates and with proper assessment, we can minimize the risks and unknowns. We offer Oracle Migration Feasibility Study services to assess the compatibility of your Oracle database with PPAS and to estimate the efforts and risks for the migration. The downtime can be reduced/avoided by setup of replication and wise choice of cut-off window.

Can I replicate from Oracle database to PostgreSQL? And how?

Yes. There are various open source and commercial tools available for setting up Oracle to PostgreSQL replication. EnterpriseDB offers one such tool xDB Replication Server, which can replicate data ​from Oracle to Postgres Plus(R) or PostgreSQL. The replication can be snapshot or CDC, scheduled or continuous and you have flexibility of choosing tables and specifying row level filters.

When setting up replication from PostgreSQL to PostgreSQL which replication is recommended?

There is no ​​’one size’ which fits all. Our team tries to engage more closely with the application and business teams of end customer before we arrive at a conclusive answer to this question. We try to find out objective and motivation behind replication, reporting needs from replicated DB, nature of replication, these factors along with few other considerations derives the discussion and leads to a decision.​

What is your recommendation of running PostgreSQL on virtual servers?

​PostgreSQL works very well with Virtualization. ​All one needs to make sure is proper provisioning of resources and proper segregation of I/O resources. Since databases are I/O bound, I/O would play a major role in any PostgreSQL setup. Same applies to virtualization as well. Our team has worked on several projects of setting up PostgreSQL on a highly available VM Ware, KVM cluster. We have also helped our customers realize the benefit of virtualization by database and workload consolidation to reduce the data center footprint and save on licensing cost. If you are looking at such a solution, let’s get in touch!

Can Pentaho help in putting Big Data to work?

Yes, it can. Pentaho supports a broad spectrum of Big Data sources such as Hadoop, NoSQL, High Performance Analytic databases to provide auto-prepare data for interactive visualization and exploration of data without going into the complexity of individual data sources to define business logic.

What is Pentaho Data Integration and where is it mostly commonly used?

Pentaho Data Integration prepares and blends data to create a complete picture of your business that drives actionable insights. The platform delivers accurate, “analytics ready” data to end users from any source. With visual tools to eliminate coding and complexity, Pentaho puts Big Data and all the data sources at the fingertips of business and IT users.

Pentaho is used for Data Integration, Data Warehousing, Machine Learning, Dashboard Reporting and Mobile BI.

How does Pentaho manage and automate data pipeline?

Pentaho not only supports appropriately governed data and efficient data delivery at any stage of process flow, but also helps to automate the entire analytic data pipeline. To manage data pipelines, Pentaho provides:

  • Data lineage capability to help users understand data origin
  • Deeper integration with SNMP through major enhancements to systems monitoring, data services caching for optimal performance of virtualized datasets
  • Support for OSGI specification a modular system with a service platform for Java, Pentaho orchestrate (melissa data) to support very specialized use cases – like address validation – also R and Python for advanced analytics – extending the pipeline.

We are looking at simplifying our IT environment. Can you please highlight how Pentaho and along with Pentaho Business Analytics can help?

Some of Pentaho’s key capabilities include:

  • Manageable and scalable self-service analytics
  • Virtualized Data Sets
  • Data Services and Power Blending
  • Inline Model Editing
  • Data Lineage
  • Push Down Optimization
  • Enhanced Enterprise Security

Pentaho Business Analytics is a complete end-to-end Open Source solution that includes data integration, data mining and business intelligence visualization. It includes connectivity to Big Data and Analytical databases, Extract-Transform-Load(ETL), OLAP services, Machine Learning and Dashboard Reporting.

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