I'm not sure if having those as shapefiles is best and what else I should do to improve those
Shapefile is a pretty fast format. Hard to beat.
about 75+ shapefiles that I've brought together as one layer using a tile index. Also, I'm needing to break up the combined layer into 5 layers using expressions. The size of each shapefile is between a few MB and up around 100MB.
Doesn't sound like a major problem. We deal with stuff on that order all the time and get good performance. Of course, 8 CPUs and a boatload of RAM help.
Did you shptree all of the shapefiles, including the tileindex? That can help a lot. There's also "sortshp" which physically sorts the file so that seeks aren't as random. (I should add that to the page.)
Beyond that, it's hard to give any specific advice without any specific details. Are you experiencing a problem with speed, or just looking to make fast even faster? Is a specific layer being problematic? Could you perhaps make the expressions more efficient, maybe merge some layers together using expressions? (you had said that you broke it into layers by expression, thought I'd ask)
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