PGConf.Russia 2023

The practice of transferring structure, logic and data from Oracle DBMS to PostgresPro DBMS. Features and main difficulties of migration. Advantages of PostgresPro in terms of porting logic.

The developer shares his experience of migration a highly loaded system in the field of railway transport from IBM DB2 for z/OS to PostgresPro in a multimaster configuration. The main focus is on the nuances of working with a cluster operating in multimaster mode, what problems had to be faced and how to solve them.

I will share the experience of migration project of an information system from a Microsoft SQL Server DBMS to Postgres PRO. The owner of the DBMS is Rosagroleasing JSC.

The volume of the DBMS database is about 6 TB (more than 300 tables, up to 4 billion records in each). The team adapted 15 ETL packages and 131 procedures with full functionality and also partial refactoring of the source code. Systems' performance has remained the same.

As we have large 1C+PostgreSQL database setups, questions often arise, the answers to which are not so easy to find even in the documentation. I would like to share my experience in solving such issues gained during several migrations of 1C from MS SQL to PostgreSQL made for clients from the RBC500 rating. This talk will cover the following points: How in-depth your statistics should be and why it can be dangerous? How can the creation of an explicit and implicit temporary table provoke the DBMS server downtime and how can we avoid it? In what case will the DBMS process be killed by the operating system due to overuse of RAM and what to do about it? Why having one database per cluster is good and why having multiple databases on one DBMS cluster is bad? If we are stick to the "1 cluster = 1 database" approach, what about server resources for test and development environments? Backups in PostgreSQL: what backup options we have