PgConf.Russia 2020

In the report, we want to talk about the experience of migrating one large system from Oracle to PostgreSQL. The system itself was built on the PHP + Oracle stack; its distinguishing feature was that all business logic was implemented in PL / SQL code. In a DBMS, there are more than 3000 packages with 4-10 functions (procedures) in each. In PHP - more than 10,000 forms with inserts of anonymous blocks used to receive data, process and save results in Oracle.

To solve this extremely voluminous work, we took ANTLR4 (a powerful parser generator for reading, processing, executing, or translating structured text), PL/SQL grammar, and created an automatic converter that allows you to convert all objects in the schema and our system from Oracle to working code for PostgreSQL.

Postgres has always had strong support for relational storage. However, there are many cases where relational storage is either inefficient or overly restrictive. This talk shows the many ways that Postgres has expanded to support non-relational storage, specifically the ability to store and index multiple values, even unrelated ones, in a single database field. Such storage allows for greater efficiency and access simplicity, and can also avoid the negatives of entity-attribute-value (eav) storage. The talk will cover many examples of multiple-value-per-field storage, including arrays, range types, geometry, full text search, xml, json, and records.

We will discuss stored procedures and functions, as well as the code within the database in general. We'll take a look at stored procedures from different angles: as a DBA, a database developer, and a backend developer. We will try to understand the specifics of stored procedures that often go against the common coding guidelines, and discuss best practices for working with stored procedures.
This is mainly a motivational talk for database and backend developers, not an advanced tech talk.

PostgreSQL 13 Feature Freeze is scheduled for April 2020. Two more commitfests are still accepting new patches. What we can say about PostgreSQL 13. It's possible that rotation rule will work so that new release wouldn't have as many new features as PostgreSQL 12 have. If even it is do, that would be good evolutionary release with a lot of medium feature and infrastructure changes, which prepares postgres for new leap. In this talk I will overview expected novelties in PostgreSQL 13. It would be more or less accurate, since there would be only one commitfest left, which results are possible to forecast.