Advanced search is really slow

[maringuu]

Through the advanced search feature I was searching for OpenSSL binaries, like so:

{
    "processed_analysis.software_components.OpenSSL": {
        "$exists": "true"
    }
}

The database consists of 1,443,268 unique files in 3,235 firmwares.
This took several minutes to complete.
Even worse when clicking on the next (in my case 2000) page I had to wait another minute.
The rest API wasn't any faster, even with setting offset to zero and limit to 50.

Several improvements that we could make:

• Speedup the code :)
• Allow for pagination in the query

As for pagination I think offset-limit pagination always has to calculate the whole result, which can be slow.
If we used cursor based pagination, we could stop right after calculating the right amount of results.