PgConf.Russia 2020

PostgreSQL 13 Feature Freeze is scheduled for April 2020. Two more commitfests are still accepting new patches. What we can say about PostgreSQL 13. It's possible that rotation rule will work so that new release wouldn't have as many new features as PostgreSQL 12 have. If even it is do, that would be good evolutionary release with a lot of medium feature and infrastructure changes, which prepares postgres for new leap. In this talk I will overview expected novelties in PostgreSQL 13. It would be more or less accurate, since there would be only one commitfest left, which results are possible to forecast.

It is our experience of the medical information system "RT MIS" transfer from MSSQL to PostgreSQL . When the necessity of transfer to PostgreSQL in our "RT MIS", one of the largest medical information systems, became imminent, we felt really terrified having assessed its amount: there was a huge number of stored procedures, functions, SQL-queries in its application code and services. It all requested transcribing, was exacerbated by demands on the system accessibility. So the variant "we awoke in the morning and PostgreSQL was working everywhere" was definitely impossible. That is why we chose another way: began eating "the elephant (PostgreSQL)" in chunks.

In my report, I am going to share our practical experience of the transfer, the instruments we used, the reason for another replication, the problems we met and their solutions. And finally, what turned out to be better: PostgreSQL or MSSQL.

I will speak about our experience in solving the fault-tolerance problem for PostgreSQL, which options we reviewed and how we chose Patroni.

I will cover solution testing, quick implementation to the production and issues we faced as well as the way we solved them.

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.