John has 40+ of years' experience working with data. Data in files and in Databases from flat files through ISAM to relational databases and most recently NoSQL. For the last 15 he's worked on a variety of Open source technologies including MySQL, PostgreSQL, Cassandra, MongoDB, Hadoop and Hbase. As a Chief Database Architect at AOL he brought MySQL in to replace Sybase and has worked hands on with MySQL databases holding hundreds of billions of rows and running millions of transactions per second. For the last 4+ years he has been working for The Pythian Group to help their customers improve their existing databases and select new ones for new applications.
In MongoDB 4.0 the MongoDB community got its first chance to use transactions. Well, except for the short lived TokuMX clone. In this talk I will discuss the capabilities and limitations of the new feature including:
- Potential impact on concurrency
This is a feature I have long waited for and I can only view as a good thing, extending the uses of MongoDB into realms previously not possible. At the same time, as with any database transactional feature, one has to be careful not to allow the feature to seriously impact concurrency.
Modern relational databases are all tied together by a well-defined standard for SQL, the latest version published in 2016. But not all SQL implementations follow the standard and even when they do, they often embellish on it and users tend to use the features they see available to them. As a result, migration between databases tends to be a challenging task. In this talk I will give some examples of database migrations I have participated in over the last twenty years and what issues we ran into with each. I will also talk in a more general sense about:
- Database only migration vs application refactoring - which is likely to have the better ROI?
- Analysis tools to help perform migration like Amazon's DMS, SQLines and DBconvert
- Database agnostic replication
- What it means to get support in the Open Source world and how to get it.