I have a probable ancestor about whom I know very little, except for the fact that he used an alias and he is mentioned in his father-in-law's will. The two names are quite common - something along the lines of "John Smith alias Jones".
How are aliases typically indexed in major genealogy website databases? E.g. Ancestry, FindMyPast, FamilySearch, TheGenealogist, or others. I am thinking primarily of pre-19th century English parish register or probate record databases, where aliases are most likely to be recorded as such.
What techniques can I use to search these databases for a person recorded with an alias? Obviously a search for John Smith or John Jones alone will turn up a vast number of results, and it is impossible to see if they mention an alias without inspecting them individually.
Any general tips for searching for ancestors with aliases are welcome too.