Oracle Goldengate or Dbvisit Replicate?

These two products offer data capture functionality and replication between multiple Database environments covering both Oracle SE and EE versions. They essentially operate by reading the source Database redo logs and pushing the data changes across to the target Database. However, there are some Important differences between these two products, some of which are listed below.

Introduction

Over the last couple of years more and more of our Standard Edition customers have been looking at using Data Replication tools for a multitude of tasks. Oracle will position Goldengate for this but the reality of the situation is that Goldengate is licensed via cores, just like Database Enterprise Edition. This means that adopting Goldengate is, according to list prices, cost prohibitive. Dbvisit Replicate is positioned to address those customers looking for a basic replication solution with a relatively low cost of adoption. Explorer have been able to negotiate significant discounts on Goldengate for Standard Edition customers and we are now able to transact Goldengate at a similar price point as Dbvisit Replicate making the two technologies relevant to compare in this blog.

Before embarking on any form of replication, it’s imperative that the project team (often DBA’s) have a good understanding of the main business objectives for replication and produce an accurate list of key technical requirements. They would need to know the size of the replication estate (No of tables involved – 100s, 1000s, more), table data types, supported OS, Database vendors involved (Oracle, DB2, SQL Server, Informix, etc.), One Way, Multi Way replication, any conflict resolutions scenarios, any specific filtering requirements, performance and monitoring requirements etc. Once this information is documented and a plan in place, they would then be in a better position to decide which of the two proposed products would satisfy these requirements.

Initial Setup & Configuration

The Goldengate install routine is simple and takes a few minutes to complete. The operation must be performed on both the source and target servers. Goldengate also has an additional option that provides a powerful and comprehensive GUI tool called Goldengate Studio that may be used to design any replication project. The Dbvisit Replicate installation is also very simple and basic. The character based setup wizard (executed on one node only) is used to assist with the initial configuration.

Architecture

Both products use either redo logs or archive logs to extract & mine transactions which are then written to GG trail files/ DBvisit PLOGS. These are sent to the target for the applying process.

Golden Gate Architecture

DB Visit Replicate Architecture

Important note: If Oracle changes the internals format of either Redo log or archive logs, then Dbvisit Replicate will have to change their internal source code to deal with the new file formats. As Goldengate is an Oracle product, this is not an issue for Oracle so you have less risk supporting this solution.

Goldengate also supports a variety of vendor Databases across different platforms – MS SQL-Server, Sybase, DB2, Informix, Sybase, Tera Data, Times Ten, MySQL and SQL/MX. DB Visit  Replicat supports a smaller set of database vendors.

Monitoring

Goldengate has developed a dedicated plug-in for Cloud Control OEM13c that allows for pro-active administration and management of all processes and no need for direct access the servers hosting the Goldengate processes.

Dbvisit Replicate provides a very basic character based console that shows the status of the replication between the two sources.

Performance

Goldengate offers parallel functionality of Extracts, Pumps and Integrated / co-ordinated Replicates and can be tailored to handle larger data loads and lower the replication elapsed time. There are a large number of parameter settings in each of these processes that can enhance the performance of each layer depending on where the bottle necks are located. The heartbeat table assists with the diagnostics of any latency issues across the two environments.

Dbvisit Replicate essentially operates on a single stream of data capture and replicate operation. The dbvrep executable handles the mining, the applying, the console and includes the setup wizard. There is some parallelization on the APPLY side for RAC Databases but these are not as advanced as Goldengate.

The overall performance of both products for small amount of data is about the same but the picture changes for larger volume of data in favour of Golden Gate.

Licensing

As mentioned earlier, Goldengate is licensed via cores. This means that when source and target Database Servers have high core counts the list price cost of Goldengate is going to be hugely different to Dbvisit Replicate. By contrast, Dbvisit Replicate is priced per source and target regardless of the number of cores. Over the last couple of years, Explorer has successfully negotiated a number of Goldengate “SE” deals where customers running Oracle Database Standard Edition(s) have been able to get significant discounts to bring the total cost of Goldengate in parity with Dbvisit. It is a shame that Oracle do not do this on a more formal basis by offering a Goldengate Standard Edition model but proves that Oracle do recognise that they need to do something to make the technology attractive to “smaller” environments.

Summary

Dbvisit Replicate is a simple and effective data capture utility that works on transactions logs and accurately delivers the data changes to the target Database. It lacks the full Database vendor support of Goldengate as well as Enterprise features such as monitoring and administration functionality via OEM, nor can it support compressed tables and TDE options.  However, for small scale replication environment it is very useful and can be configured very quickly. By contrast, Goldengate is an enterprise replication tool that can support large and very complex replication environments so it really does come back to the business requirements, commercials and overall “value” that each product offers.

Author: Hamid Ansari

Job Title: Technical Consultant

Bio: Hamid is a Technical consultant at DSP-Explorer, he has a BA(Hons) in Data Processing / Business computing from the University of Sunderland and is a specialist in Oracle Database and associated technologies. He has over 25 years of working with Oracle RDMS starting with version 5.1. His main focus areas are Oracle GoldenGate, RAC, DataGuard, Engineered Systems and Oracle Cloud. He has worked across various companies in the Middle East, Europe, UK and US.