PGConf.SPB 2023

Fuzzing research is feeding random input data to a program (or a part of it) (in fact, randomness is very conditional) and seeing what we get out of it. And we repeat it many times on many processors.

Fuzzing a large monolithic program complex is never a simple task. It requires extraordinary solutions. In this talk, I will tell you what and how we searched with the help of fuzzing and what results it led to.

• Investigation of data type parsing functions (input-functions): for warming up;
• Investigation of functions implementing operations between types (op-functions): it is better to consider the structure here;
• Network subsystem fuzzing: let's pretend we are POSIX calls, it's cheaper that way;
• Recovering disk context: we need Groundhog Day.

A story about funny bugs and ridiculous hand gestures will be included.

During the years of its existence, Postgres Pro piled up a pool of problems when query execution was inappropriately slow or a query was too expensive to be executed, so it was never executed. Almost always in our practice, this was due to the choice of a non-optimal query plan. In our story, we will talk about a very unconventional attempt to solve this problem by re-planning queries. We will tell you what it is, how it works, who will find it helpful and the prospects for using this feature.

Unfortunately, ideal computer systems exist only in science fiction books. PostgreSQL is not exception and sometimes problems may occur. I would like to discuss how to correctly (and incorrectly) try to solve a problem, which way to choose, which tool to use.

The talk is of interest to both beginners and experienced users and database administrators.

Postgres Pro is investing heavily to make it easy for customers to migrate to their database from Oracle Database.

This talk describes in detail the advanced Postgres Pro DBMS technologies designed to solve this problem:

• support for package functionality in PL/pgSQL, including the package initialization section and global package variables;
• ora2pgrpo utility for automatic conversion of package code from Oracle PL/SQL syntax to PL/pgSQL;
• PG Pro Application Info extension designed for instrumentation and monitoring of the state of sessions, including the execution of long operations (session longops) - a functional analogue of the package DBMS_APPLICATION_INFO in Oracle DBMS;
• new system packages UTL_MAIL and UTL_SMTP for sending emails from stored procedures to Postgres Pro DBMS (full functional analogue of the corresponding packages in Oracle DBMS);
• new system package UTL_HTTP for interacting with external sources from stored procedures in Postgres Pro DBMS (analogous to the package of the same name in Oracle DBMS);

Also in this talk there will be a short story about the directions of development of the Postgres Pro DBMS aimed at further simplifying migration from Oracle DBMS.