Анализ вариантов оптимизации ресурсоёмкого SQL-запроса: Вариант-1 «EXISTS»

track_io_timing = 'on'
listen_addresses = '0.0.0.0'
logging_collector = 'on'
log_directory = '/log/pg_log'
log_destination = 'stderr'
log_rotation_size = '0'
log_rotation_age = '1d'
log_filename = 'postgresql-%u.log'
log_line_prefix = '%m| %d| %a| %u| %h| %p| %e| '
log_truncate_on_rotation = 'on'
log_checkpoints = 'on'
archive_mode = 'on'
archive_command = 'true'
archive_timeout = '30min'
checkpoint_timeout = '15min'
checkpoint_warning = '60'
checkpoint_completion_target = '0.9'
min_wal_size = '2GB'
max_wal_size = '8GB'
synchronous_commit = 'on'
wal_compression = 'on'
random_page_cost = '1.1'
effective_io_concurrency = '300'
wal_sender_timeout = '0'
autovacuum_naptime = '1s'
autovacuum_vacuum_scale_factor = '0.01'
autovacuum_analyze_scale_factor = '0.005'
autovacuum_vacuum_cost_delay = '2ms'
autovacuum_max_workers = '4'
autovacuum_work_mem = '256MB'
vacuum_cost_limit = '4000'
bgwriter_delay = '10ms'
bgwriter_lru_multiplier = '4'
bgwriter_lru_maxpages = '400'
max_locks_per_transaction = '256'
max_pred_locks_per_transaction = '256'
shared_buffers = '1919MB'
effective_cache_size = '5757MB'
work_mem = '14MB'
temp_buffers = '14MB'
maintenance_work_mem = '479MB'
max_worker_processes = '8'
max_parallel_workers = '8'
max_parallel_workers_per_gather = '4'
idle_in_transaction_session_timeout = '1h'
statement_timeout = '8h'
pg_stat_statements.track_utility = 'off'
max_parallel_maintenance_workers = '4'
hash_mem_multiplier = '2'
autovacuum_vacuum_insert_scale_factor = '0.01'
shared_preload_libraries = 'pg_stat_statements , pg_wait_sampling'
commit_delay = '1000'
log_autovacuum_min_duration = '0'
wipe_file_on_delete = 'on'
wipe_heaptuple_on_delete = 'on'
wipe_mem_on_free = 'on'
wipe_memctx_on_free = 'on'
wipe_xlog_on_free = 'on'
log_connections = 'on'
log_disconnections = 'on'
pg_stat_statements.track = 'all'
max_connections = '1000'

demo=# \d bookings
                    Unlogged table "bookings.bookings"
    Column    |           Type           | Collation | Nullable | Default
--------------+--------------------------+-----------+----------+---------
 book_ref     | character(6)             |           | not null |
 book_date    | timestamp with time zone |           | not null |
 total_amount | numeric(10,2)            |           | not null |
Indexes:
    "bookings_pkey" PRIMARY KEY, btree (book_ref)
    "idx_bookings_book_date" btree (book_date)
Referenced by:
    TABLE "tickets" CONSTRAINT "tickets_book_ref_fkey" FOREIGN KEY (book_ref) REFERENCES bookings(book_ref)

demo=# \d tickets
               Unlogged table "bookings.tickets"
     Column     |     Type     | Collation | Nullable | Default
----------------+--------------+-----------+----------+---------
 ticket_no      | text         |           | not null |
 book_ref       | character(6) |           | not null |
 passenger_id   | text         |           | not null |
 passenger_name | text         |           | not null |
 outbound       | boolean      |           | not null |
Indexes:
    "tickets_pkey" PRIMARY KEY, btree (ticket_no)
    "idx_tickets_book_ref" btree (book_ref)
    "tickets_book_ref_passenger_id_outbound_key" UNIQUE CONSTRAINT, btree (book_ref, passenger_id, outbound)
Foreign-key constraints:
    "tickets_book_ref_fkey" FOREIGN KEY (book_ref) REFERENCES bookings(book_ref)
Referenced by:
    TABLE "segments" CONSTRAINT "segments_ticket_no_fkey" FOREIGN KEY (ticket_no) REFERENCES tickets(ticket_no)

demo=#  \d segments
                Unlogged table "bookings.segments"
     Column      |     Type      | Collation | Nullable | Default
-----------------+---------------+-----------+----------+---------
 ticket_no       | text          |           | not null |
 flight_id       | integer       |           | not null |
 fare_conditions | text          |           | not null |
 price           | numeric(10,2) |           | not null |
Indexes:
    "segments_pkey" PRIMARY KEY, btree (ticket_no, flight_id)
    "idx_segments_flight_id" btree (flight_id)
    "idx_segments_flight_id_fare_conditions" btree (flight_id, fare_conditions)
    "idx_segments_ticket_no" btree (ticket_no)
    "segments_flight_id_idx" btree (flight_id)
Check constraints:
    "segments_fare_conditions_check" CHECK (fare_conditions = ANY (ARRAY['Economy'::text, 'Comfort'::text, 'Business'::text]))
    "segments_price_check" CHECK (price >= 0::numeric)
Foreign-key constraints:
    "segments_flight_id_fkey" FOREIGN KEY (flight_id) REFERENCES flights(flight_id)
    "segments_ticket_no_fkey" FOREIGN KEY (ticket_no) REFERENCES tickets(ticket_no)
Referenced by:
    TABLE "boarding_passes" CONSTRAINT "boarding_passes_ticket_no_flight_id_fkey" FOREIGN KEY (ticket_no, flight_id) REFERENCES segments(ticket_no, flight_id)

demo=# \d boarding_passes
                 Unlogged table "bookings.boarding_passes"
    Column     |           Type           | Collation | Nullable | Default
---------------+--------------------------+-----------+----------+---------
 ticket_no     | text                     |           | not null |
 flight_id     | integer                  |           | not null |
 seat_no       | text                     |           | not null |
 boarding_no   | integer                  |           |          |
 boarding_time | timestamp with time zone |           |          |
Indexes:
    "boarding_passes_pkey" PRIMARY KEY, btree (ticket_no, flight_id)
    "boarding_passes_flight_id_boarding_no_key" UNIQUE CONSTRAINT, btree (flight_id, boarding_no)
    "boarding_passes_flight_id_boarding_time" btree (flight_id, boarding_time)
    "boarding_passes_flight_id_seat_no_key" UNIQUE CONSTRAINT, btree (flight_id, seat_no)
Foreign-key constraints:
    "boarding_passes_ticket_no_flight_id_fkey" FOREIGN KEY (ticket_no, flight_id) REFERENCES segments(ticket_no, flight_id)

demo=# \d flights
                                  Unlogged table "bookings.flights"
       Column        |           Type           | Collation | Nullable |           Default
---------------------+--------------------------+-----------+----------+------------------------------
 flight_id           | integer                  |           | not null | generated always as identity
 route_no            | text                     |           | not null |
 status              | text                     |           | not null |
 scheduled_departure | timestamp with time zone |           | not null |
 scheduled_arrival   | timestamp with time zone |           | not null |
 actual_departure    | timestamp with time zone |           |          |
 actual_arrival      | timestamp with time zone |           |          |
Indexes:
    "flights_pkey" PRIMARY KEY, btree (flight_id)
    "flights_route_no_scheduled_departure_key" UNIQUE CONSTRAINT, btree (route_no, scheduled_departure)
    "idx_flights_route_no" btree (route_no)
    "idx_flights_scheduled_departure" btree (scheduled_departure DESC)
Check constraints:
    "flight_actual_check" CHECK (actual_arrival IS NULL OR actual_departure IS NOT NULL AND actual_arrival IS NOT NULL AND actual_arrival > actual_departure)
    "flight_scheduled_check" CHECK (scheduled_arrival > scheduled_departure)
    "flight_status_check" CHECK (status = ANY (ARRAY['Scheduled'::text, 'On Time'::text, 'Delayed'::text, 'Boarding'::text, 'Departed'::text, 'Arrived'::text, 'Cancelled'::text]))
Referenced by:
    TABLE "segments" CONSTRAINT "segments_flight_id_fkey" FOREIGN KEY (flight_id) REFERENCES flights(flight_id)

WITH random_period AS (
    SELECT 
        start_date,
        start_date + INTERVAL '30 days' AS end_date
    FROM (
        SELECT 
            book_date AS start_date
        FROM bookings
        WHERE book_date <= (SELECT MAX(book_date) FROM bookings) - INTERVAL '30 days'
        ORDER BY RANDOM()
        LIMIT 1
    ) AS random_date
)
SELECT 
    b.book_ref,
    b.book_date,
    t.ticket_no,
    t.passenger_name,
    s.flight_id,
    f.status,
    f.scheduled_departure,
    f.actual_departure,
    bp.seat_no,
    bp.boarding_no,
    rp.start_date AS period_start,
    rp.end_date AS period_end
FROM random_period rp
CROSS JOIN LATERAL (
    SELECT *
    FROM bookings b
    WHERE b.book_date BETWEEN rp.start_date AND rp.end_date
) b
LEFT JOIN tickets t ON b.book_ref = t.book_ref
LEFT JOIN segments s ON t.ticket_no = s.ticket_no
LEFT JOIN flights f ON s.flight_id = f.flight_id
LEFT JOIN boarding_passes bp ON 
    s.ticket_no = bp.ticket_no 
    AND s.flight_id = bp.flight_id
ORDER BY b.book_date, t.ticket_no;

 Sort  (cost=2544355.52..2550077.32 rows=2288717 width=93) (actual time=58778.563..59050.999 rows=1146771 loops=1)
   Sort Key: b.book_date, t.ticket_no
   Sort Method: external merge  Disk: 121832kB
   CTE random_period
     ->  Subquery Scan on random_date  (cost=66429.70..66429.71 rows=1 width=16) (actual time=2883.937..2883.945 rows=1 loops=1)
           ->  Limit  (cost=66429.70..66429.70 rows=1 width=16) (actual time=2883.919..2883.925 rows=1 loops=1)
                 InitPlan 2
                   ->  Result  (cost=0.45..0.46 rows=1 width=8) (actual time=1.994..1.996 rows=1 loops=1)
                         InitPlan 1
                           ->  Limit  (cost=0.43..0.45 rows=1 width=8) (actual time=1.989..1.991 rows=1 loops=1)
                                 ->  Index Only Scan Backward using idx_bookings_book_date on bookings  (cost=0.43..128154.91 rows=7113192 width=8) (actual time=1.988..1.989 rows=1 loops=1)
                                       Heap Fetches: 0
                 ->  Sort  (cost=66429.24..72356.90 rows=2371064 width=16) (actual time=2883.917..2883.918 rows=1 loops=1)
                       Sort Key: (random())
                       Sort Method: top-N heapsort  Memory: 25kB
                       ->  Index Only Scan using idx_bookings_book_date on bookings bookings_1  (cost=0.43..54573.91 rows=2371064 width=16) (actual time=2.183..1714.099 rows=6894590 loops=1)
                             Index Cond: (book_date <= ((InitPlan 2).col1 - '30 days'::interval))
                             Heap Fetches: 0
   ->  Hash Left Join  (cost=685482.92..2046557.85 rows=2288717 width=93) (actual time=49378.694..57307.629 rows=1146771 loops=1)
         Hash Cond: (s.flight_id = f.flight_id)
         ->  Merge Right Join  (cost=681880.13..2036946.95 rows=2288717 width=69) (actual time=49326.107..56627.660 rows=1146771 loops=1)
               Merge Cond: (s.ticket_no = t.ticket_no)
               ->  Merge Left Join  (cost=1.12..1264914.46 rows=20598448 width=25) (actual time=3.919..32375.016 rows=6564405 loops=1)
                     Merge Cond: ((s.ticket_no = bp.ticket_no) AND (s.flight_id = bp.flight_id))
                     ->  Index Only Scan using segments_pkey on segments s  (cost=0.56..424624.50 rows=20598448 width=18) (actual time=3.875..1950.364 rows=6564405 loops=1)
                           Heap Fetches: 0
                     ->  Index Scan using boarding_passes_pkey on boarding_passes bp  (cost=0.56..637941.24 rows=19870556 width=25) (actual time=0.033..25169.883 rows=6564405 loops=1)
               ->  Materialize  (cost=681879.01..690532.20 rows=1730639 width=58) (actual time=21308.253..22022.391 rows=1146771 loops=1)
                     ->  Sort  (cost=681879.01..686205.61 rows=1730639 width=58) (actual time=21308.245..21812.491 rows=862459 loops=1)
                           Sort Key: t.ticket_no
                           Sort Method: external merge  Disk: 58600kB
                           ->  Nested Loop Left Join  (cost=0.87..464448.40 rows=1730639 width=58) (actual time=2886.101..18909.459 rows=862459 loops=1)
                                 ->  Nested Loop  (cost=0.43..31711.08 rows=790355 width=31) (actual time=2884.013..3268.567 rows=397632 loops=1)
                                       ->  CTE Scan on random_period rp  (cost=0.00..0.02 rows=1 width=16) (actual time=2883.941..2883.946 rows=1 loops=1)
                                       ->  Index Scan using idx_bookings_book_date on bookings b  (cost=0.43..23807.51 rows=790355 width=15) (actual time=0.063..308.659 rows=397632 loops=1)
                                             Index Cond: ((book_date >= rp.start_date) AND (book_date <= rp.end_date))
                                 ->  Index Scan using idx_tickets_book_ref on tickets t  (cost=0.43..0.52 rows=3 width=34) (actual time=0.038..0.038 rows=2 loops=397632)
                                       Index Cond: (book_ref = b.book_ref)
         ->  Hash  (cost=2247.35..2247.35 rows=108435 width=28) (actual time=52.383..52.385 rows=108435 loops=1)
               Buckets: 131072  Batches: 1  Memory Usage: 7377kB
               ->  Seq Scan on flights f  (cost=0.00..2247.35 rows=108435 width=28) (actual time=0.024..22.614 rows=108435 loops=1)
 Planning Time: 37.456 ms
 Execution Time: 59151.413 ms

WITH random_period AS (
    SELECT 
        book_date AS start_date,
        book_date + INTERVAL '30 days' AS end_date
    FROM bookings 
    ORDER BY RANDOM() 
    LIMIT 1
)
SELECT 
    b.book_ref,
    b.book_date,
    t.ticket_no,
    t.passenger_name,
    s.flight_id,
    f.status,
    f.scheduled_departure,
    f.actual_departure,
    bp.seat_no,
    bp.boarding_no
FROM bookings b
LEFT JOIN tickets t ON b.book_ref = t.book_ref
LEFT JOIN segments s ON t.ticket_no = s.ticket_no
LEFT JOIN flights f ON s.flight_id = f.flight_id
LEFT JOIN boarding_passes bp ON s.ticket_no = bp.ticket_no AND s.flight_id = bp.flight_id
WHERE EXISTS (
    SELECT 1 FROM random_period rp 
    WHERE b.book_date BETWEEN rp.start_date AND rp.end_date
)
ORDER BY b.book_date, t.ticket_no;	

 Sort  (cost=2920577.58..2926299.37 rows=2288716 width=77) (actual time=52126.170..52366.389 rows=1076571 loops=1)
   Sort Key: b.book_date, t.ticket_no
   Sort Method: external merge  Disk: 97592kB
   CTE random_period
     ->  Limit  (cost=191879.84..191879.84 rows=1 width=24) (actual time=4368.349..4368.353 rows=1 loops=1)
           ->  Sort  (cost=191879.84..209662.82 rows=7113192 width=24) (actual time=4368.346..4368.349 rows=1 loops=1)
                 Sort Key: (random())
                 Sort Method: top-N heapsort  Memory: 25kB
                 ->  Seq Scan on bookings  (cost=0.00..156313.88 rows=7113192 width=24) (actual time=0.033..3039.736 rows=7113192 loops=1)
   ->  Hash Left Join  (cost=945420.57..2306495.49 rows=2288716 width=77) (actual time=43510.983..50848.328 rows=1076571 loops=1)
         Hash Cond: (s.flight_id = f.flight_id)
         ->  Merge Right Join  (cost=941817.78..2296884.59 rows=2288716 width=53) (actual time=43446.797..50235.025 rows=1076571 loops=1)
               Merge Cond: (s.ticket_no = t.ticket_no)
               ->  Merge Left Join  (cost=1.12..1264914.46 rows=20598448 width=25) (actual time=1.708..31823.629 rows=10235420 loops=1)
                     Merge Cond: ((s.ticket_no = bp.ticket_no) AND (s.flight_id = bp.flight_id))
                     ->  Index Only Scan using segments_pkey on segments s  (cost=0.56..424624.50 rows=20598448 width=18) (actual time=1.675..2642.891 rows=10235420 loops=1)
                           Heap Fetches: 0
                     ->  Index Scan using boarding_passes_pkey on boarding_passes bp  (cost=0.56..637941.24 rows=19870556 width=25) (actual time=0.022..21355.771 rows=10235420 loops=1)
               ->  Materialize  (cost=941816.66..950469.85 rows=1730639 width=42) (actual time=14800.486..15461.183 rows=1076571 loops=1)
                     ->  Sort  (cost=941816.66..946143.25 rows=1730639 width=42) (actual time=14800.477..15274.393 rows=834764 loops=1)
                           Sort Key: t.ticket_no
                           Sort Method: external merge  Disk: 43680kB
                           ->  Nested Loop Left Join  (cost=0.43..731315.04 rows=1730639 width=42) (actual time=4370.165..12416.101 rows=834764 loops=1)
                                 ->  Nested Loop Semi Join  (cost=0.00..298577.73 rows=790355 width=15) (actual time=4369.207..8500.573 rows=391485 loops=1)
                                       Join Filter: ((b.book_date >= rp.start_date) AND (b.book_date <= rp.end_date))
                                       Rows Removed by Join Filter: 6721707
                                       ->  Seq Scan on bookings b  (cost=0.00..120747.92 rows=7113192 width=15) (actual time=0.589..818.523 rows=7113192 loops=1)
                                       ->  CTE Scan on random_period rp  (cost=0.00..0.02 rows=1 width=16) (actual time=0.001..0.001 rows=1 loops=7113192)
                                 ->  Index Scan using idx_tickets_book_ref on tickets t  (cost=0.43..0.52 rows=3 width=34) (actual time=0.008..0.009 rows=2 loops=391485)
                                       Index Cond: (book_ref = b.book_ref)
         ->  Hash  (cost=2247.35..2247.35 rows=108435 width=28) (actual time=63.974..63.976 rows=108435 loops=1)
               Buckets: 131072  Batches: 1  Memory Usage: 7377kB
               ->  Seq Scan on flights f  (cost=0.00..2247.35 rows=108435 width=28) (actual time=0.789..32.556 rows=108435 loops=1)
 Planning Time: 10.731 ms
 Execution Time: 52459.463 ms