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Diffstat (limited to 'content/posts/postgres-aggregates/merging-ctes.txt')
| -rw-r--r-- | content/posts/postgres-aggregates/merging-ctes.txt | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/content/posts/postgres-aggregates/merging-ctes.txt b/content/posts/postgres-aggregates/merging-ctes.txt new file mode 100644 index 0000000..5c958dd --- /dev/null +++ b/content/posts/postgres-aggregates/merging-ctes.txt @@ -0,0 +1,71 @@ + QUERY PLAN +------------------------------------------------------------------------------------------------------------------------------------------------------------------- + Hash Left Join (cost=19871.86..20138.39 rows=10000 width=32) (actual time=84.427..88.463 rows=10000 loops=1) + Output: products.id, products.name, COALESCE(product_reviews.num_reviews, '0'::bigint), COALESCE(product_orders.num_orders, '0'::bigint) + Inner Unique: true + Hash Cond: (products.id = product_orders.product_id) + Buffers: shared hit=8402 + -> Hash Left Join (cost=2754.21..2994.48 rows=10000 width=24) (actual time=19.962..22.583 rows=10000 loops=1) + Output: products.id, products.name, product_reviews.num_reviews + Inner Unique: true + Hash Cond: (products.id = product_reviews.product_id) + Buffers: shared hit=1049 + -> Seq Scan on public.products (cost=0.00..214.00 rows=10000 width=16) (actual time=0.002..0.719 rows=10000 loops=1) + Output: products.id, products.name, products.description, products.price, products.created_at + Buffers: shared hit=114 + -> Hash (cost=2631.44..2631.44 rows=9822 width=12) (actual time=19.909..19.911 rows=10000 loops=1) + Output: product_reviews.num_reviews, product_reviews.product_id + Buckets: 16384 Batches: 1 Memory Usage: 558kB + Buffers: shared hit=935 + -> Subquery Scan on product_reviews (cost=2435.00..2631.44 rows=9822 width=12) (actual time=17.667..18.894 rows=10000 loops=1) + Output: product_reviews.num_reviews, product_reviews.product_id + Buffers: shared hit=935 + -> HashAggregate (cost=2435.00..2533.22 rows=9822 width=12) (actual time=17.667..18.342 rows=10000 loops=1) + Output: reviews.product_id, count(reviews.id) + Group Key: reviews.product_id + Batches: 1 Memory Usage: 1425kB + Buffers: shared hit=935 + -> Seq Scan on public.reviews (cost=0.00..1935.00 rows=100000 width=8) (actual time=0.011..4.796 rows=100000 loops=1) + Output: reviews.id, reviews.review_date, reviews.comment, reviews.product_id + Buffers: shared hit=935 + -> Hash (cost=16993.16..16993.16 rows=9959 width=12) (actual time=64.403..64.453 rows=10000 loops=1) + Output: product_orders.num_orders, product_orders.product_id + Buckets: 16384 Batches: 1 Memory Usage: 558kB + Buffers: shared hit=7353 + -> Subquery Scan on product_orders (cost=16793.98..16993.16 rows=9959 width=12) (actual time=62.164..63.412 rows=10000 loops=1) + Output: product_orders.num_orders, product_orders.product_id + Buffers: shared hit=7353 + -> Finalize HashAggregate (cost=16793.98..16893.57 rows=9959 width=12) (actual time=62.164..62.867 rows=10000 loops=1) + Output: orders.product_id, count(orders.id) + Group Key: orders.product_id + Batches: 1 Memory Usage: 1425kB + Buffers: shared hit=7353 + -> Gather (cost=14603.00..16694.39 rows=19918 width=12) (actual time=56.542..58.444 rows=30000 loops=1) + Output: orders.product_id, (PARTIAL count(orders.id)) + Workers Planned: 2 + Workers Launched: 2 + Buffers: shared hit=7353 + -> Partial HashAggregate (cost=13603.00..13702.59 rows=9959 width=12) (actual time=54.293..54.991 rows=10000 loops=3) + Output: orders.product_id, PARTIAL count(orders.id) + Group Key: orders.product_id + Batches: 1 Memory Usage: 1425kB + Buffers: shared hit=7353 + Worker 0: actual time=53.312..53.970 rows=10000 loops=1 + Batches: 1 Memory Usage: 1425kB + Buffers: shared hit=2406 + Worker 1: actual time=53.322..54.071 rows=10000 loops=1 + Batches: 1 Memory Usage: 1425kB + Buffers: shared hit=2395 + -> Parallel Seq Scan on public.orders (cost=0.00..11519.67 rows=416667 width=8) (actual time=0.006..13.835 rows=333333 loops=3) + Output: orders.id, orders.order_date, orders.customer_name, orders.product_id + Buffers: shared hit=7353 + Worker 0: actual time=0.008..13.768 rows=327216 loops=1 + Buffers: shared hit=2406 + Worker 1: actual time=0.007..13.584 rows=325720 loops=1 + Buffers: shared hit=2395 + Planning: + Buffers: shared hit=171 + Planning Time: 0.410 ms + Execution Time: 89.503 ms +(67 rows) + |