2024
Digitalize - PG Optimization Basics of 2:07:51
    https://www.youtube.com/watch?v=gA3A_epB3So
    ! 13:00 - from index pages go into buffer-cache in RAM
    ! 37:00 - select ... from employee e join contacts ec using(employee_id) -- on e.employee_id = ec.employee_id
    ! 39:00 - data access methods: seq-scan, idx-scan(with going into table), index-only-scan(without going into table), bitmap-heap-scan
    ! 45:00 - Seq Scan on employee (cost=0.00..173528.84 rows ...)
    !             0.00 - cost of first raw obtaining, 173528.84 - cost of all rows obtaining
    ! 47:00 select relpages, current_setting('seq_page_cost'), relpages*current_setting('seq_page_cost')::int as total
    !       from pg_class where relname='employee';
    !       relpages:         73 530
    !       current_setting:  1
    !       total:            73 530
    ! 53:00 selectivity (0.0 .. 1.0) - percentage/proportion of chosen rows
    !       idx is effectively used only on low-selectivity, otherwise - seq scan
    ! 1:08:00 - vacuum analyze - for updating statistics
    ! 1:17:00 - create extension pg_stat_statements; alter system set shared_preload_libraries = 'pg_stat_statements';
    ! 1:18:00 - other perf-related settings !!!
    ! recommendation - https://www.youtube.com/playlist?list=PLaFqU3KCWw6JW80WBHPOe-SMJD2NOjmge
JPoint - Zhilin - PG Can Make a Pain 0:00 of 45:49
    https://www.youtube.com/watch?v=pTWfjyeQ5Ks
    https://jokerconf.com/talks/0bd645ad3a0f48c292547db572a1c7eb
WorkSolutions - Kostenko - Postgres World Optimization Misteries ru 0:00 of 32:50
    https://www.youtube.com/watch?v=MeTDmLyYD9k
2023
Tenzor - Backend School of p9
    https://www.youtube.com/playlist?list=PLt0vzWoDuwcTdFnp-QWtx2yEvKMDlPw7l
2022
Slurm - PG Optimization Webinar ru 3:00 of 1:20:15
    https://www.youtube.com/watch?v=oSsirfUIR4w