Extending PostgreSQL in C: A Tutorial

PostgreSQL is one of the most readily extensible databases in the world. Custom data types, aggregations, functions, and more can be easily and safely written in C.

This hands-on tutorial covers the basics of writing functions, data types, and aggregates in C. It is recommended (though not strictly required) that bring their own laptops and be prepared to actually try the exercises.

Topics covered include: 1. The PostgreSQL type system 2. Creating a simple custom type in C 3. Common errors for non-C programmers 4. Creating a simple aggregate in C

There will be many opportunities for questions and discussion through the tutorial.

The possibilities of profiling plpgsql code - available tools

I like stored procedures - it is great technology. But like any other technologies it allows to write not well optimized code. It is not easy to write optimized code, sql statements in complex large applications. On second hand, there are some tools, that can be used very easily, that can help. Postgres has built-in tracking functions possibility. There are PLProfiler and plpgsql_check. With these tools is easy work to detect slow part of applications.With this knowledge, the fix of performance issue is less magic.

Как я перестал беспокоиться и перенес 60K строк из 150 процедур PL/SQL в Postgres.

I will share our experience of migrating a server application for Russian railways from Oracle 11g Standard Edition to vanilla PostgreSQL 11.5.
At the time of migration, the database contained about 200 stored procedures of over 60000 lines of Oracle PL/SQL code (which has been developed since 2006, that is, for more than 12 years), about 250 tables, and 50GB of data.
Starting with a prologue, we'll describe our adventures along the migration process, as well as pleasant and unpleasant surprises we encountered, and finally get to an epilogue and a happy end. The story is told on behalf of an Oracle user exploring Postgres.

План + запрос = ?.. Когда анализ запроса в радость

Odd things in query plan analysis - wasted time and "unnecessary" buffers.
Structural hints in a plan. How to help a developer with optimization without writing a single line of code. How to match plan nodes with query text and take advantage of this information.