PGConf.Russia 2023

ORM libraries are widely used in backend development – let's take this for granted. ORM libraries are improving, developers are learning from their own and others' mistakes, and many have learned to write code for ORM that generates quite optimal queries for typical operations. Yet, limited functionality of existing tools is another problem related to ORM. This is especially true for Postgres, which has a lot of operators and constructs (both in the core and in extensions) that go beyond the SQL standard.

With LinqToDb ORM library you can write extensions that implement any SQL operator or construct very easy, literally using just one line. Full-text search, KNN, CTE (including recursive ones), working with arrays and jsonb, array_agg and jsonb_object_agg, table functions and LATERAL JOIN - all this can be easily used in ORM, which I will demonstrate during this talk!

The major task of workload monitoring tools is to provide measurable statistics about most resource intensive activities in the DBMS. They can't solve any issues but the points for concentrating optimization efforts can be highlighted. We’ll talk about the extensions pg_profile and pgpro_pwr, their architecture, features and use cases.

How does network latency affect performance when using synchronous replication? If a primary node fails, how long will our cluster not be reachable? How much data can be lost? Will there be any anomalies when reading from standby? We are designing our network architecture, give us a minimum RTT value for cluster solution! Many DBAs have to face these issues when designing and implementing cluster solutions. In this short talk we will tell how to quickly estimate RTT, RTO, RPO values, with the help of which Open Source tools one can test cluster solution and experimentally verify the design parameters, which metrics values can be used as a guide in design.