PGConf.SPB 2023

Migration from Oracle DB/Application. What is the price?

Lowering the threshold for a programmer to enter the development of business applications using the Database-Centric approach on the Low Code Development Platform based on PostgreSQL.

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.

One of the requirements for the operation of the Corosync/Pacemaker failover cluster is the fencing of the failed node. In virtual environments, fencing is implemented by disabling the virtual machine through a hypervisor, in a cluster on physical servers - through IPMI/ILO. But what if it is impossible to organize fencing, for example, in the cloud environment? During this presentation, I will list and explain alternative methods of fencing a failed node.

Recently, one of the most common migration methods has become migration using the free ora2pg tool. However, many note the extremely low performance of this tool, especially when it comes to databases of 1 Terabyte and above. This presentation describes how to significantly speed up database migration using oracle_fdw alone or in combination with ora2pg.