shcca175problem03evolveavroschema.sh

use retail;
select * from orders_avro as X where X.order_date in (
select inner.order_date from (
select Y.order_date, count(1) as total_orders
from orders_avro as Y
group by Y.order_date
order by total_orders desc, Y.order_date desc
limit 1
) i
);
// Evolve Avro Schema
// 1. Get schema file
hadoop fs -get /user/hive/schemas/order/orders.avsc
// 2. Open schema file
gedit orders.avsc
// 3. Edit schema file
{
"type" : "record",
"name" : "orders",
"doc" : "Sqoop import of orders",
"fields" : [ {
"name" : "order_id",
"type" : [ "null", "int" ],
"default" : null,
"columnName" : "order_id",
"sqlType" : "4"
}, {
"name" : "order_date",
"type" : [ "null", "long" ],
"default" : null,
"columnName" : "order_date",
"sqlType" : "93"
}, {
"name" : "order_customer_id",
"type" : [ "null", "int" ],
"default" : null,
"columnName" : "order_customer_id",
"sqlType" : "4"
},{
"name" : "order_style",
"type" : [ "null", "string" ],
"default" : null,
"columnName" : "order_style",
"sqlType" : "12"
}, {
"name" : "order_zone",
"type" : [ "null", "int" ],
"default" : null,
"columnName" : "order_zone",
"sqlType" : "4"
}, {
"name" : "order_status",
"type" : [ "null", "string" ],
"default" : null,
"columnName" : "order_status",
"sqlType" : "12"
} ],
"tableName" : "orders"
}
// 3. copy modified schema file to HDFS again
hadoop fs -copyFromLocal -f orders.avsc /user/hive/schemas/order/orders.avsc