Assuming you have a database keyed by ISBN number, you can reduce the size by just saying

push @{$user_books{$user_id}}, $ISBN;

[download]
This gives you a HoA with just the book keys. Without the database you can still save space and normalize your data by keeping a hash over unique isbns.

After Compline,
Zaxo

In reply to Re: How to Calculate Memory Needs? by Zaxo
in thread How to Calculate Memory Needs? by mrbbking

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