Best way to cross matching large datasets


Posted on 16th Feb 2014 07:03 pm by admin

Hi,

Im running a script where am I cross matching about 200 000 data sets with each other. Each data set consists of 8 parameters and I want to count all datasets which have similar or the same parameters for each data set.

Right now, I am doing the matching via a MySql query which im calling about 200 000 times. The problem is that using a query is extremely expensive… it takes up to 2 hours until the script is done. So I am wondering if there is a better method to cross match data sets and if some of could help me find a better solution.

While researching I found out that arrays may be a faster alternative to queries. And so far, I identified 3 possible ways for cross matching:

1. nested foreach () loops
foreach($array as ar1)
foreach($array as ar2)
if ($ar1[0] == $ar1[0])….

2. Using an Array_map with Callback function, so that i would have only one "hand coded" loop
foreach($array as arr)
if ($arr[0] == $parameter)….

3. Array walk where i could save one "hand coded" loop as well.

Theoretically would be the best/fastest way to go about it? Can Anyone tell me what technically the difference between those 3 ways is? And which one is the better approach or if there other alternatives to them?

I am thankful for any advice that helps me reduce execution time!

No comments posted yet

Your Answer:

Login to answer
343 Like 48 Dislike
Previous forums Next forums
Other forums

echo $rows help
Hi all,

Hopefully something simple that I don't know!

I have this:

Code: [Selec

Getting rid of quotes when printing data
Hi Guys, I use the filter_var FILTER_SANITIZE_STRING to filter the textarea input. The function esca

PHP & Images [Resize, Crop, Save]
Hey! Well I have a little dilema, hoping I could find some guidance.

I have a CMS and on the

Oracle Connectivity
Hi Every One,

Can we access SAP from oracle database.If it possible then please spec

simplexml and xpath - Need some help
Hello,

I am trying to parse an xml which comes back from Amazon and I am trying to know how m

change text color with a jQuery code
Hihow can I change the text in a asp:TextBox to a different color when I start typing using jQuery?I

duplicate record notification
In my database, after insertion of records, I want to know if the record inserted is duplicate or no

Coding Critique
I was hoping someone could take a second and look down my code and see if they see any problems with

Users and Groups with PHP Classes
Hi,

I have setup what I hope to be a good working User class. Now I want to introduce group m

is_dir() problem
Hello,

I'm buidling a php scripts that dynamically get's subfolders from a specific folder.

Sign up to write
Sign up now if you have flare of writing..
Login   |   Register
Follow Us
Indyaspeak @ Facebook Indyaspeak @ Twitter Indyaspeak @ Pinterest RSS



Play Free Quiz and Win Cash