Schema customerInfoSchema = new Schema.Builder()
.addColumnLong("customerID")
.addColumnString("customerName")
.addColumnCategorical("customerCountry", Arrays.asList("USA","France","Japan","UK"))
Schema customerPurchasesSchema = new Schema.Builder()
.addColumnLong("customerID")
.addColumnTime("purchaseTimestamp", DateTimeZone.UTC)
.addColumnLong("productID")
.addColumnInteger("purchaseQty")
.addColumnDouble("unitPriceUSD")
Join join = new Join.Builder(Join.JoinType.Inner)
.setJoinColumns("customerID")
.setSchemas(customerInfoSchema, customerPurchasesSchema)