database sorting algorithms.

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От Jian He
Тема database sorting algorithms.
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Msg-id CAMV54g0QLUWEXdrCbywoB3C-UGhLMBqL49xAKMk6j1w7cmXCXQ@mail.gmail.com
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Ответы Re: database sorting algorithms.  (Francisco Olarte <folarte@peoplecall.com>)
Re: database sorting algorithms.  (Gavan Schneider <list.pg.gavan@pendari.org>)
Список pgsql-general

Been self study Database, from database I deep dived into sorting algorithms.

Databases can do in-memory QuickSort. It also has an on-disk MergeSort.

For MergeSort: I follow this tutorial https://youtu.be/6pV2IF0fgKY?t=1108  (around 1 minutes only)

But I am still not fully understanding about nlogn. I understand how many passes it will take, that is logn. 
Yes each pass will sort N elements.
But I still don't get the N stand for in n*logn.
Why does each pass take  n time to sort it?






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