notes/db/sql/postgres/docs/courses/pg-pro.txt

2023
PostgresProfessional - DBA2 Administration of 18 parts
    https://www.youtube.com/playlist?list=PLaFqU3KCWw6L72nIqJ-l-pscc6WxtW4G1
PostgresProfessional - RogovLuzanovTolmachyov - QPT13 - Query Optimization of p12
    https://postgrespro.ru/education/courses/QPT
    https://www.youtube.com/playlist?list=PLaFqU3KCWw6JW80WBHPOe-SMJD2NOjmge
    p10 - profiling 0:00 of 37:49
        https://www.youtube.com/watch?v=o5T0ApVFcDc
    p9 - Statistics of 46:28
        https://www.youtube.com/watch?v=I4cedjshRrs
        ! pg_class - num of tuples/pages (reltuples/relpages) for tables
        !   setting default_statistics_target = 100
        !       "selection size" for table analysis
        ! pg_stats - n_distinct, null_tract - ration of uniq vals
        !   most_common_vals, most_common_freqs
        ! pg_statistics_ext, pg_statistics_ext_data, pg_stats_ext view (for dependent column values)
    p8 - Merge Join of 24:26
        https://www.youtube.com/watch?v=urerHBMGc14
        ! set should be sorted first (either from downstream node of plan or from idx)
        ! Merge Join: ...
        !   Merge Cond: ...
        ! 18:00 Sort:
        !         Sort Key:
        !         Sort Method:
        !         Buffers: ...
        ! 20:00 Agg...
        !         Gather Merge:...
    p7 - Hash Join of 29:03
        https://www.youtube.com/watch?v=zH_LJAsYvcU
        ! can be in a single (Batches: 1) or double-batches (when can't feet into RAM)
        ! 3:00 work_mem * hash_mem_multiplier
        ! 5:00 Hash Join
        !         Hash Cond: (... = ...)
        !         -> Seq Scan on <tbl> alias
        !         -> Hash
        !             -> Seq Scan on ...
        !   Hash Full Join
        ! 7:00 hash joing can be used for DISTINCT
        !   Hash Aggregate ...
        !     Group Key ...
        ! explain (analyze, settings - to show all non-std param-values, ... )
        !     
        ! hash-table need to be build my lower set of rows (to decrease RAM usage)
        ! 12:00
        ! Hash Cond:
        ! Join Filter: ...
        ! 13:00 - double-batches (not feet into RAM, use tmp-files)
        ! 17:00 Hash (...)
        !         Buckets: ... Batches: 4 ...
        !           Buffers: ..., temp written=5217
    p6 - Inner Loop Join of 20:35
        https://www.youtube.com/watch?v=VeGJAQo9ogM
        ! Bitmap Index Scan
        !   Heap Blocks: exact=4413 (we have enough RAM)
        !     ... lossy=3989 (non-precise fragments, contains links to table segments for re-check)
        ! !! set/reset workmem
        ! 4:00 select a.title, s.name
        !       from albums a join songs s on a.id =  s.a_id;
        !   Nested Loop - node of plan
        ! 12:00 select * from aircrafts a left join seats s on (a.aircraft_code = s.aircraft_code) where a.model like '...';
        !   Nested Loop Left Join - node of plan
        ! 19:00 nested-loop-join is effective on middle/sized cardinality only (for big ones need index)
        !   + join can be done on anly condition
    p5 - Bitmap Scan 0:00 of 25:57
        https://www.youtube.com/watch?v=j7e7EANyJhE
    p4 - Inex Scan of 41:10
        https://www.youtube.com/watch?v=iu35dYTchu4
        ! 8:00 select current_setting('random_page_cost'); -> 4
        !   !!! need to decrease in case of ssd-disks
        ! current_setting
        !   'random_page_cost'
        !   'seq_page_cost'
        !   'cpu_tuple_cost'
        !   'cpu_index_tuple_cost'
        !   'cpu_operator_cost'
        ! 18:00 - other params
        !   min_parallel_index_scan_size
        !   ...per_...
        ! 26:00 - create index ... include(...)
        ! 33:00 - duplicate index records
        ! 34:30 - pg has dup-idx-records exclusion mechanism (works only upon index-page-split)
        !   create index ... with(deduplicate_items=off)  -- to switchi it off
        ! 37:00 - set enable_seqscan = off; -- to temporary disable seqscan
    p3 - Sequential Scan of 47:06
        https://www.youtube.com/watch?v=X2DOIf0DfJ0
        ! parallel processing is not-efficitent for full seq-load, but is effective for the case of agg-n
        ! "Parallel Seq Scan" -> "Partial Aggregate" -> "Gather"
        ! 34:00 set max_parallel_workers_per_gather = 5;
        ! 46:00 "post_parallel_mode" - allows to check whether query can be paral-d in principle
    p2 - Query Execution of 43:14
        https://www.youtube.com/watch?v=_6ce4YFFScc
        ! 26:00 - set jit = off;
        ! prepare model(varchar) as select model from aircrafts where iircraft_code = $1;
        ! select * from pg_prepared_systems;
        ! deallocate ... (or just close session)
        ! 27:00 - declare c cursor for select * from aircrafts;
        !   fetch c; ... close c;
    p1 - Air Demobase of 30:07
        https://www.youtube.com/watch?v=k9cloEiIPC0
    p0 - Intro of 8:49
        https://www.youtube.com/watch?v=2-UmottNWWk
2022
PostgresProfessional - Hacking PostgreSQL of p8
    https://www.youtube.com/playlist?list=PLaFqU3KCWw6Jfb8IBNk3hZ07dxMxjfGtv
    ! need to look
2021
PostgresProfessional - Rogov - DEV2 of 21 videos
    https://www.youtube.com/playlist?list=PLaFqU3KCWw6K3AyBVcZGdXMtM2xvjHA1N
    https://postgrespro.ru/education/courses/DEV2
PostgresProfessional - Rogov - Luzanov - Bashtaev - DBA1 Administration of 19 parts
    https://www.youtube.com/playlist?list=PLaFqU3KCWw6LPcuYVymLcXl3muC45mu3e
    https://postgrespro.ru/education/courses/DBA1
2019
PostgresProfessional - DBA3 Administration of 9 parts
    https://www.youtube.com/playlist?list=PLaFqU3KCWw6KEakTSrRWrekNI-z9U1ypF
    https://postgrespro.ru/education/courses/DBA3
PostgresProfessional - DBA2 Administration of 18 parts
    https://www.youtube.com/playlist?list=PLaFqU3KCWw6KycrRthIC6mESoLLQen1k6
    https://postgrespro.ru/education/courses/DBA2
PostgresProfessional - DBA1 Administration of 19 parts
    https://www.youtube.com/playlist?list=PLaFqU3KCWw6KycrRthIC6mESoLLQen1k6
PostgresProfessional - Rogov - Luzanov - DBA1 Administration of 19 parts
    https://www.youtube.com/playlist?list=PLaFqU3KCWw6JhHBp07QSu9uE8zahhKnTn
    https://postgrespro.ru/education/courses/DBA1
Morgunov - sqlprimer
    https://www.youtube.com/playlist?list=PLaFqU3KCWw6J1NEI8hjYlvGnD4Y7Sxx4r
    https://postgrespro.ru/education/university/sqlprimer
    https://edu.postgrespro.ru/sqlprimer/sqlprimer-2019-msu-03.pdf
    https://edu.postgrespro.ru/sqlprimer/sqlprimer-2019-msu-04.pdf
Novikov
    https://edu.postgrespro.ru/dbtech/
    https://www.youtube.com/playlist?list=PLaFqU3KCWw6K5maTyTF2NdcbpNsPHRecu
2018
PostgresProfessional - Rogov - Luzanov - DEV1 of 21 videos
    https://www.youtube.com/playlist?list=PLaFqU3KCWw6LNR1IZ814whJe89J1tRQ3t
    https://postgrespro.ru/education/courses/DEV1