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Question on Sort node's actual rows - Mailing list pgsql-general

From Victor Yegorov
Subject Question on Sort node's actual rows
Date
Msg-id CAGnEbojZBC44gXzgUZ0zJMwyEXjjbysrenTJayDrbPdBafrbcA@mail.gmail.com
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Responses Re: Question on Sort node's actual rows  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-general
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Greetings.

I'm looking at a plan: http://explain.depesz.com/s/sPv

And I have a question. Why in the following snippet `Sort` node reports 128818 rows, although
child node returned only 352?

"->  Sort  (cost=37.06..37.94 rows=352 width=20) (actual time=4.441..16.971 rows=128818 loops=1)
"      Sort Key: ts.currency
"      Sort Method: quicksort  Memory: 52kB
"      Buffers: shared hit=13
"      ->  Seq Scan on transaction_slip ts  (cost=0.00..22.18 rows=352 width=20) (actual time=0.041..4.035 rows=352 loops=1)
"            Filter: (account_id = 101)
"            Rows Removed by Filter: 382
"            Buffers: shared hit=13

This is:
PostgreSQL 9.3.1 on x86_64-apple-darwin12.5.0, compiled by i686-apple-darwin11-llvm-gcc-4.2 (GCC) 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.11.00), 64-bit


--
Victor Y. Yegorov

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