PgConf.Russia 2016

This talk will cover "hasql", a highly-efficient library for integration of Haskell and PostgreSQL. The library provides an API for declarative programming, which is also quite flexible and terse. The talk will cover the benefits of declarative programming as well as the architectural and technical solutions behind the library, including the implementation of the PostgreSQL binary protocol. Hasql is used in PostgREST, a popular modern restful API for Postgres.

We'll discuss how does Linux work with virtual memory. The following topics will be covered: * x86-64 page table, context switch and page fault; * internals of virtual memory management (VMM) in Linux; * page eviction methods in Linux, page cache and anonymous pages; * huge and gigantic pages, transparent huge pages; * how mmap(2) works and what madvise(2), msync(2) etc. provide; * why large databases don't use mmap(2), but rather implement buffer pool on their own; * ans surely how to tune Linux VMM using sysctl.

Alibaba has provided a relational database service (RDS) for postgres in our public cloud platform (aliyun.com, the currently biggest public cloud in China). We are also enabling internal applications to use postgres in our other internet business and we can share our experience

In the speech we consider the current PostgreSQL planner model, then the possibilities of applying machine learning methods for planner improvement and the obtained results.