Re: Optimizing count(), but Explain estimates wildly off

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От Laurenz Albe
Тема Re: Optimizing count(), but Explain estimates wildly off
Дата
Msg-id 822fd29fb50b8a8035fd91efa309754b3a02c439.camel@cybertec.at
обсуждение исходный текст
Ответ на Re: Optimizing count(), but Explain estimates wildly off  (Chema <chema@interneta.org>)
Ответы Re: Optimizing count(), but Explain estimates wildly off  (Chema <chema@interneta.org>)
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On Thu, 2024-02-29 at 17:15 -0600, Chema wrote:
> No major changes after doing Analyze, and also Vacuum Analyze.

Indeed.

This caught my attention:

> ->  Parallel Seq Scan on pricescope_items  (cost=0.00..1027794.01 rows=3277101 width=522) (actual
time=0.753..41654.507rows=2621681 loops=3) 

Why does it take over 41 seconds to read a table with less than
3 million rows?  Are the rows so large?  Is the tabe bloated?
What is the size of the table as measured with pg_relation_size()
and pg_table_size()?

Yours,
Laurenz Albe



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