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.

As you probably know, PostgreSQL has a number of distinct features compared to other DBMSs. For example, Postgres can process and store many different types of data. However, you need to know something about them before using them. In this talk, we will find the reason why queries to the table begin to slow down (and autovacuum / vacuum has nothing to do with it) and try to speed up such queries. I will tell you how integer data types work in PostgreSQL and touch on the topic of speeding up such queries. And finally, let's talk about how to make your data in tables take up less space while increasing the speed of queries to this data.

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.

Traditionally, fault tolerance in Postgres is implemented using built-in replication mechanisms and external utilities that monitor the state of running Postgres instances and react accordingly when various failures occur. In this presentation, I will tell you what we like and what we don’t like about this approach, which alternative we see, what we have been able to achieve to date and what we want to get done by the time of release, which is planned for December.