Hive: Creating an external table: Show partitions does nothing - hive

Question

I am creating an external table in my own database :
create external table test1 (
event_uid string,
event_type_id int,
event_category_id int,
event_date string,
log_date string,
server string,
server_type string,
process_id int,
device_id string,
account_id string,
ip_address string,
category_id string,
content_id string,
entitlement_id string,
product_id string,
sku string,
title_id string,
service_id string,
order_id bigint,
transaction_id bigint,
company_code string,
product_code string,
key_value_pairs map<string,string>,
process_run_id string)
partitioned by (A string, B string, C string)
location '/data/a1/pnt/lte/formatted/evt'
When I try SHOW PARTITIONS TEST, I just get OK as an output.
However, there is a table with the same same DDL and the same location in another database which is giving results when I do SHOW PARITITIONS TEST. I have also tried MSCK REPAIR TABLE TEST which displays partitions .
Please suggest

Answer 1

When using partitions no actual partitions are created when you execute your DDL. The partitions are created when you load data into your table. So you need to load data and then you would be able to see the partitions with the show partitions statement.

Answer 2

When we create an EXTERNAL TABLE with PARTITION, we have to ALTER the EXTERNAL TABLE with the data location for that given partition. However, it need not be the same path as we specify while creating the EXTERNAL TABLE.
hive> ALTER TABLE test1 ADD PARTITION (A=2016, B=07, C=19)
hive> LOCATION '/data/a1/pnt/lte/formatted/evt/somedatafor_20160719'
hive> ;
When we specify LOCATION '/data/a1/pnt/lte/formatted/evt' (though its optional) while creating an EXTERNAL TABLE we can take some advantage of doing repair operations on that table. So when we want to copy the files through some process like ETL into that directory, we can sync up the partition with the EXTERNAL TABLE instead of writing ALTER TABLE statement to create another new partition.
If we already know the directory structure of the partition that HIVE would create for next data set(say here for C=20), we can simply place the data file in that location like '/data/a1/pnt/lte/formatted/evt/A=2016/B=07/C=20/data.txt' and run the statement as shown below:
hive> MSCK REPAIR TABLE test1;
The above statement will sync up the partition to the hive meta store of the table "test1".