I need import a big spreasheet, with 25.000 itens, what solution is better, change cron frequency or change values of number lines import each time.
I means, without causes any problem for my system, of course ...
make sure the cron frequency is high enough to not get launched twice.
that is a lot of records so you may run into PHP memory limit issues, but give it a try, if it stops you will know how many records get created in the system and can cut your CSV from there and repeat
I did it in past, I did experiment with different batch sizes during each import iteration. According to me, smaller batch sizes can reduce the immediate impact on system resources but may prolong the overall import process.
Thanks