Gravando em esquemas específicos com RPostgreSQL

library(RPostgreSQL)
drv <- dbDriver("PostgreSQL")
con <- dbConnect(drv, dbname = "db", host = "host", port = 5432,
                 user = "user", password = "pwd")
dbWriteTable(con, c("yourschema", "yourtable"), value = yourRdataframe)
dbDisconnect(con)