Affect on std::cout on performance of the program

Question

I have written a program which would fetch file details and place them in the SQLite database. In this process i have observed two scenarios:

Scenario 1:

Loop through each and every file and fill the file details(path) in to the database(sqlite3).
While for each file encountered,keep a counter and print the same via std::cout. Time taken to execute this program:30mins

Scenario 2:

Loop through each and every file and fill the file details(path) in to the database(sqlite3).

Time taken to execute this program:7mins

I am very unclear as of why just because of std::cout,the time taken is 5 times more than that of not printing it?

Any pointers on this scenario is highly appreciated.Thanks a lot.

Regards, Ravi

Perhaps printf might be faster, if you want to try. Otherwise like Hulk said it :) — rozina, Mar 10 '14 at 08:52
[how many times do you use `std::endl` vs. `"\n"`?](http://stackoverflow.com/q/213907/819272) — TemplateRex, Mar 10 '14 at 08:53

score 0 · Answer 1 · answered Mar 10 '14 at 08:54

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try to use std::ios_base::sync_with_stdio(false), by default std::cout sync with stdio

answered Mar 10 '14 at 08:54

Mike Minaev

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Sure.Thanks.Will give a try and let you know the results. – user3264565 Mar 10 '14 at 08:57

score 0 · Answer 2 · edited May 23 '17 at 11:57

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Printing to console is costly. Usually more time-consuming than writing to a file.

I bet your code could run in less than a minute. Make sure you surround some inserts in a transaction. You can also use multiple inserts in one statement, like explained in answers to this question.

edited May 23 '17 at 11:57

Community

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answered Mar 10 '14 at 08:55

Dariusz

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I have already been using transaction and auto vacuum options from sqlite3 db.I am only worried about why exactly the cout is taking more time(5 times).. – user3264565 Mar 10 '14 at 08:56

Affect on std::cout on performance of the program

2 Answers2