If I use the fetchall_arrayref, maybe it is not worth to change this structure?

It's still much easier and cheaper to traverse an array in order than a hash. So, if your hash keys are numeric, you almost certainly should be using an array instead.

does perl spend a lot of resources to create a strucure?

Different structures have different costs. Hashes are "more expensive" than arrays.

If your dealing with a few hundred or a few thousand items, the differences aren't worth worying about.

It's only when you start dealing with very large datasets, several 100 thousands or more, that the difference can becomes important.

But, re-sorting a hash everytime you traverse it, even with a few hundred elements is sufficiently costly that if you can avoid doing so by using an array, it doesn't make sense to not use the array!

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
Lingua non convalesco, consenesco et abolesco. -- Rule 1 has a caveat! -- Who broke the cabal?
"Science is about questioning the status quo. Questioning authority".
The "good enough" maybe good enough for the now, and perfection maybe unobtainable, but that should not preclude us from striving for perfection, when time, circumstance or desire allow.

In reply to Re^5: Best complex structure? by BrowserUk
in thread Best complex structure? by Anonymous Monk

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