sql - Extremely slow query using CONNECT BY Oracle 10 -


i have table challenge containing 12000 rows. every point connects 4 points around it, example 100 connects 99 101 11 , 189. tried small scale table , worked fine increased size of table query became exponentially slower , won't finish. here's query

select level, origin, destination challenge  destination = 2500 start origin = 1 connect nocycle  prior destination = origin;

any advice on how optimize query appreciated.

so you're finding every path node 1 node 2500 in degree-4 graph (rectangular lattice?) of thousands of nodes. expect there'll quite lot of them. did challenge ask count them? because think point have figure out how many there doing math, not brute force computation.

for example, if it's 50x50 rectangular grid node 1 , node 2500 in opposite corners, minimum path length 100 steps. path of 100 steps have 50 of them horizontal , 50 of them vertical, , can come in order. figure out how many ways can arrange string of 50 h's , 50 v's , might find it's number mighty oracle have bit of problem with. (generating rows, is. doing calculation requires large integer arithmetic, oracle can quite once tell formula.)

and query worse that. doesn't ask minimum-length paths. return paths of length 102 take step away destination somewhere along way. , paths of length 104 take 2 backward steps. , paths of length 2498 visit of nodes! counting paths more complicated counting short paths because have exclude ones cross themselves.


Comments

Post a Comment

Popular posts from this blog

How to mention the localhost in android -

i trying call localhost in android application. unfortunately not possible used several methods emulator local host http://10.0.2.2/android/dbconnection.php and network ip address http://192.168.1.xx/android/dbconnection.php also http://localhost:8080/android/dbconnection.php but nothing connected localhost. purpose refer stackoverflow answers not working i facing same problem when worked on localhost. referred stackoverflow answer got solution create new emulator works fine in new emulator.
Read more

php - Calling a template part from a post -

i include iframe within post in wordpress. located inside content of post, meaning cannot in post template file, otherwise either before or after. i'd add facebook plugin within posts: <div id="socialwrap"><div class="fb-like" data-href="http://onlinearizonahomes.info" data-send="true" data-width="450" data-show-faces="true" data-font="arial"></div></div> i thinking of calling template part within post <?php get_template_part( 'social' ); ?> cannot use php within post without plugin (i'd avoid using plugin this). an alternative using javascript create html in post, seems unnecessary use of javascript. what best way add html within wordpress post? you can use shortcode. add functions.php function cudjex_fbshare( $atts, $content = null ) { global $post; $link = get_permalink($post->id); return '<div id="socialwrap...
Read more

c# - String.format() DateTime With Arabic culture -

check below code snippet, namespace testdateconvertion { class program { static void main(string[] args) { datetime testvalue = new datetime(2013, 12, 15, 15, 33, 44); cultureinfo culture = new cultureinfo("ar-sa"); string stringvalue = string.format(culture, "{0:d} {0:hh:mm:ss}", testvalue); console.writeline(stringvalue); console.readline(); } } } it gives output 22/02/35 15:33:44 i not getting how possible. whats 35 doing in output there that's 13/12/2015 in hijri, 35 means 1435 in hijri, default date format saudi arabia.
Read more