On Sunday, 9 March, 2014 19:38, Stephen Chrzanowski <pontia...@gmail.com> inquired:
>Apologies for the interruption and sort of off topic, but, is .timer part >of the CLI only or is it part of the SQL language? Can I get the result >of a timer from a call, or do I have to put a wrapper on my wrapper? .timer is a shell command specific to the sqlite shell and not part of the SQL language. You would have to put your own wrapper to collect timing data. >On Sun, Mar 9, 2014 at 8:17 PM, Keith Medcalf <kmedc...@dessus.com> >wrote: > >> >> sqlite> create virtual table n using wholenumber; >> sqlite> .timer on >> sqlite> select sum(sqrt(value)) from n where value between 1 and 1000; >> 21097.4558874807 >> Run Time: real 0.001 user 0.000000 sys 0.000000 >> sqlite> select sum(sqrt(value)) from n where value between 1 and >1000000; >> 666667166.458841 >> Run Time: real 0.160 user 0.156250 sys 0.000000 >> sqlite> select sum(sqrt(value)) from n where value between 1 and >> 1000000000; >> 21081851083598.4 >> Run Time: real 151.021 user 151.031250 sys 0.000000 >> sqlite> select sum(value) from n where value between 1 and 1000000000; >> 500000000500000000 >> Run Time: real 89.341 user 89.343750 sys 0.000000 >> >> A native sqrt takes about 60 ns per operation. >> >> >-----Original Message----- >> >From: sqlite-users-boun...@sqlite.org [mailto:sqlite-users- >> >boun...@sqlite.org] On Behalf Of big stone >> >Sent: Sunday, 9 March, 2014 03:35 >> >To: sqlite-users@sqlite.org >> >Subject: Re: [sqlite] Suggestion to add "locate" as a broader version >of >> >"instr" >> > >> >Hello Max, >> > >> >Your link is pretty interesting. It looks that : >> >- method1 should be easily implemented with SQLite "floating point" >> >representation, >> >- and with a very very small code size. >> > >> >Here is the benchmarking of the two available methods : >> > >> >>https://raw.github.com/stonebig/ztest_donotuse/master/square_rooting_ben >c >> >hmark.GIF >> > >> > >> >So : >> >- your method is only 3 times slower than the python sqrt(), >> >- if SQLite team accepts to sacrifice a few bytes to implement sqrt(), >we >> >may benefit a 389% speed-up (300/27*.652/1.86) at least. >> > (300/27*.652/1.86) >> > >> >sqrt() is very interesting for statistics on-the-go over sql datas. >> > >> >Regards, >> >_______________________________________________ >> >sqlite-users mailing list >> >sqlite-users@sqlite.org >> >http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users >> >> >> >> _______________________________________________ >> sqlite-users mailing list >> sqlite-users@sqlite.org >> http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users >> >_______________________________________________ >sqlite-users mailing list >sqlite-users@sqlite.org >http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
