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What's the best way to buffer a large map?



  • I have program that contains a QMap that uses a custom data structure as a key and maps to a float. (The key has a somewhat complex design). The program has grown to the point that I need to index about 7 million entries in my map, and this is causing me to run out of memory.

    I'm thinking that I might need to store all this info in some sort of local database instead, but am unsure of the best way to go about this. I could use SQL, but I am worried that it might be slow. Does Qt provide a fast way to create a file-backed map?


  • Lifetime Qt Champion

    @kitfox said in What's the best way to buffer a large map?:

    Does Qt provide a fast way to create a file-backed map?

    No, you have to do it by your own. Maybe you can use QCache and load it from the db if it's no longer in the cache.



  • Have you reviewed the spacial database literature? It seems that you are discussing a common GIS issue.



  • I think if you've grown to the point of 7million keys then you're way into the realm of using a real database and using something like SQL queries to pull information.


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