A German IT services outfit specialising in the insurance market has migrated 500 IBM Db2 databases to the EnterpriseDB (EDB) iteration of Postgres in a sign of life after proprietary wares.
BG-Phoenics joins Indian credit reference agency TransUnion CIBIL, which shifted Oracle workloads to EDB, providing evidence for the viability of open-source database tech for demanding business workloads.
Harald Stefan, head of platform databases for BG Phoenics, was in 2017 responsible for around 1,500 operational databases supporting 8,500 IT users in the social insurance market. His team took the decision to replace all of its IBM technology, including Db2, Tivoli and Websphere, which by the end of 2019 made up the core infrastructure supporting the content management system.
Databases varied in size from smaller than 100GB to 2.5TB.
The reason for the departure from Big Blue's technology was the complexity of the architecture and subsequent effect on management and licensing. It also had an impact on deployment times.
"It was highly consolidated and complex to operate, and difficult to get patches in," Stefan said at online conference Postgres Build 2020. "When you created a machine, there is a team involved for storage, for network, for Active Directory and so on. It took time to get a change to the teams. There were weekend activities because of this architecture."
After a long evaluation process, his team decided to migrate from Db2 instances to EDB Postgres – the open-source Postgres with a few mission critical bells and whistles from EDB, the commercial company contributing to and supporting the open-source project.
For the migration project, the team was looking to automate the deployment of servers, run a simple licensing model, expand the use of containers and use S3 storage as backup. The capacity to support database optimiser hints was one of the main reasons for picking EDB, Stefan said. In addition, the criteria included high availability, partitioning, point-of-time recovery, support access, ACID compliance, and so on.
"The devil is really in the details. For example, [if] a few databases cannot handle hints and applications using this they are out," he said of the bidding process.
BG Phoenics chose EDB Postgres because it met these criteria and supported migration from both Db2 and Oracle, providing tooling at no additional cost.
Having said that, there was no direct way to automate migration from Db2 to EDB or migrate the character set. As such, the tech team had to use a migration tool for the data type and character conversion, selecting Full Convert.
The team split the schema and tables into patches and automated them to finish at the same time. "That is a lot of work, but it is possible and you can automate it," Stefan added.
With this approach, the team was able to complete the migration by the end of 2019.
Since going live, the user found the deployment of new instances in Postgres much faster than it had been in Db2, down from around 20 hours spread over two weeks to 40 to 60 minutes. "Now we can go really agile and react in hours," Stefan said.
One of the lessons learned from the migration was not to underestimate the emotional attachment IT teams have to certain technologies. Stefan said it was hard for people who have been working with Db2 and Oracle for 20 years or more to accept the change, pointing to a graph suggesting they would go through phases of shock, refusal, rational understanding, and emotional acceptance. "But now we're having fun with Postgres," he said.
BG Phoenics was not alone as a large corporate user successfully migrating away from a proprietary database to Postgres. Speaking to The Register in the summer, Ganadeva Bandyopadhay, associate vice president of IT at TransUnion CIBIL, described the migration from Oracle to Postgres EDB.
The company was looking to revamp older applications based on "rapidly outgoing concepts like heavy database servers with a lot of business logic within the database code," Bandyopadhay said.
The company also found its Oracle licences were being underused, but the rigidity in the rules made it difficult to move them onto different virtual instances and convert from the processor-based to the "Named User Plus" licensing.
Starting from 2015, Bandyopadhay and his team wanted to remove the business logic from the main database, improving performance and flexibility in the architecture, something he said would have been difficult to do with Oracle.
"It was nothing against Oracle, but our logic was to address Oracle features which are built within the database," he said. "There is a cost to that which we had accepted for a long time, but with the changing expectations [from the business], we had to really revamp and flatten out the databases and put the business logic into somewhere else in the middle tier."
Having completed the migration in 2017, TransUnion CIBIL found the Postgres EDB-based system was able to achieve higher throughput at lower licensing costs, but not before careful consideration in reskilling its internal IT team.
"One of the advantages of the EDB Postgres is that it is compatible with the [data centre] virtual machines, which allows us the flexibility to quickly scale up databases as per the business growth," Bandyopadhay said.
While some Oracle or Db2 users are looking for alternatives, other are happy to stick with the technology, aware of the trade-offs.
Speaking to The Register last week, Oracle UK User Group member advocate Neil Chandler said: "Postgres has its strengths. But, like all of the open-source offerings, it is not as scalable as a proprietary database like Oracle or SQL Server. It's just not there. It may be for a very good department-size database; just good enough."
For Oracle users, at least, the downside was obvious. "I would argue the best database in the world is Oracle. The most expensive database in the world is also Oracle," he said.
With huge global installed bases, Oracle and IBM's Db2 are not likely to be seriously threatened by Postgres any time soon. But a couple of trailblazers have shown there are colours other than red and blue. ®