PostgresOpen 2019 Explain Plans And You

แชร์
ฝัง
  • เผยแพร่เมื่อ 25 ธ.ค. 2024

ความคิดเห็น •

  • @kunalmandalia1165
    @kunalmandalia1165 4 ปีที่แล้ว +9

    Excellent talk. The speaker is keen for the audience to learn as opposed to appearing clever and that shines through.

  • @india_is_greatest
    @india_is_greatest 2 ปีที่แล้ว

    by far the best talk I listened so far about Postgres

  • @kundan621
    @kundan621 4 ปีที่แล้ว +2

    Thanks for sharing. Excellent presentation and great content.

  • @SARANSASIDHARAN1
    @SARANSASIDHARAN1 ปีที่แล้ว

    Excellent talk!

  • @НикитаНагорный-ч3о
    @НикитаНагорный-ч3о 2 ปีที่แล้ว

    Thanks. It was very helpful

  • @deryckhenson4353
    @deryckhenson4353 4 ปีที่แล้ว +3

    Very good talk. Wish resolution was higher couldn't read much on the screen :\

  • @YogeshJadhav96
    @YogeshJadhav96 3 ปีที่แล้ว +1

    Great Talk.

  • @mourinhoalex1992
    @mourinhoalex1992 4 ปีที่แล้ว

    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 ?