What is the execution order of this plan: Sort (cost=87.71..88.75 rows=418 width=40) Sort Key: language.name DESC -> Hash Join (cost=1.14..69.51 rows=418 width=40) Hash Cond: (film.language_id = language.language_id) -> Seq Scan on film (cost=0.00..66.50 rows=418 width=21) Filter: (rating = ANY ('{R,PG-13}'::mpaa_rating[])) -> Hash (cost=1.06..1.06 rows=6 width=25) -> Seq Scan on language (cost=0.00..1.06 rows=6 width=25) As I understand from the talk, it should be: 1. The nodes that have the startup cost equals to 0 will be the nodes that gets run first, so these 2 nodes runs in parallel: Seq Scan on film, Seq Scan on language 2. Then this node gets run: Hash (cost=1.06..1.06 rows=6 width=25) 3. Then this node: Hash Join 4. Finally: Sort Do I understand it correctly ? If not, then what is the correct execution order of the nodes in this plan ?
Excellent talk. The speaker is keen for the audience to learn as opposed to appearing clever and that shines through.
by far the best talk I listened so far about Postgres
Thanks for sharing. Excellent presentation and great content.
Excellent talk!
Thanks. It was very helpful
Very good talk. Wish resolution was higher couldn't read much on the screen :\
Great Talk.
What is the execution order of this plan:
Sort (cost=87.71..88.75 rows=418 width=40)
Sort Key: language.name DESC
-> Hash Join (cost=1.14..69.51 rows=418 width=40)
Hash Cond: (film.language_id = language.language_id)
-> Seq Scan on film (cost=0.00..66.50 rows=418 width=21)
Filter: (rating = ANY ('{R,PG-13}'::mpaa_rating[]))
-> Hash (cost=1.06..1.06 rows=6 width=25)
-> Seq Scan on language (cost=0.00..1.06 rows=6 width=25)
As I understand from the talk, it should be:
1. The nodes that have the startup cost equals to 0 will be the nodes that gets run first, so these 2 nodes runs in parallel: Seq Scan on film, Seq Scan on language
2. Then this node gets run: Hash (cost=1.06..1.06 rows=6 width=25)
3. Then this node: Hash Join
4. Finally: Sort
Do I understand it correctly ? If not, then what is the correct execution order of the nodes in this plan ?