PgConf.Russia 2016

Diasoft Platform company's technology solutions for migration of applications from proprietary DBMS (on the examples of Oracle and Microsoft SQL Server) to PostgreSQL will be presented in the talk. These solutions are implemented in Diasoft Database Adapter software.

Our technology solutions allow to automate: 1) migration of database schema (including translation of stored procedure and function code); 2) migration of data; 3) migration of client applications without any change in their source code.

First working on Oracle, we could not ignore appearance and growth of PostgreSQL. I will describe how we came to PostgreSQL and share some experience of migrating a large medical system.

• developing a code converter;
• packages migration;
• our patches solving some of the migration problems.

Common Java wisdom is to use PreparedStatements and Batch DML in order to achieve top performance. It turns out one cannot just blindly follow the best practices. In order to get high throughput, you need to understand the specifics of the database in question, and the content of the data.

In the talk we will see how proper usage of PostgreSQL protocol enables high performance operation while fetching and storing the data. We will see how trivial application and/or JDBC driver code changes can result in dramatic performance improvements. We will examine how server-side prepared statements should be activated, and discuss pitfalls of using server-prepared statements.