Handling a 450,000x450,000 array with PHP

[guarriman]

Hi.

I'd like to create a program to handle data (natural numbers)
within a 450,000 x 450,000 array. I'm considering PHP, but
I don't know is it's powerful enough to manage it.

Thank you very much.

[Piranha]

First you need to know how big that array will be. The array will be around 800 GB if each number is a 4 byte integer. I would like to say that handling this kind of data is not anything for a normal computer, it does not matter what platform or program language you use.

But do you really need it as an array? You can probably do it with a database, and it will be a lot faster. It may still be very slow, and you still need lots of storing space, but I think it is a better idea.

[guarriman]

Hi.

Thank you very much for your quick answers. I try to handle data from a
450x450 meter surface.

I've got 100,000 elements distributed on this surface, and each
square millimeter can hold one or more elements. So the array to create
is a sparse one: most of square millimeters holds zero elements, and
the rest, 20 or less.

I'm trying to find the square meter with more elements inside.

Thank you very much.

[NogDog]

Perhaps you do not need an array of the surface, but rather include attributes for each object with their current x/y coordinates? (And if this is done in a database, then you have the built in ability to sort elements by those coordinates to facilitate map rendering and such.)

[MarkR]

Because of the overhead of PHP, it is unlikely to be feasible to handle a 450,000 x 450,000 array natively.

If you really need to do this, consider using C++ instead. I am assuming that your system has enough RAM to do it (and probably 64-bit might be a good idea so you don't run short of address space).

Otherwise, consider an alternative approach.

PHP is generally a poor choice for high performance scientific computing due to its poor performance, weak typing system etc.

Mark