In order to plan the Incremental and Full Crawl scenarios and schedule , I’m adding the below information in this regard:
Note1: a full crawl should be done at least once before performing incremental crawl.
Note2: the above scenarios are covered for crawled content within SharePoint 2010/2013 farm, (not file shares , exchange public folders, custom connectors , etc… for those scenarios incremental crawl behavior might differ).
How about .SystemUpdate()? It seems like that one is only picked up by Full Crawl.
It seems that (at least in 2010) security changes are taken into account on incremental fileshare crawl!
Thanks Issa for putting this together - very helpful. You readers might be benefited from this related post too: