setDT extremely slow for very wide input #5426
Description
DT = replicate(1e7, 1, simplify = FALSE)
system.time(setDT(DT))
# user system elapsed
# 23.043 0.216 23.261 {{ message }}
DT = replicate(1e7, 1, simplify = FALSE)
system.time(setDT(DT))
# user system elapsed
# 23.043 0.216 23.261