Hi Driller:
I get
hive_alltypes.parquethere:https://issues.apache.org/jira/browse/DRILL-2005. I
create table on hive and query it:
hive desc alltypesparquet;
OK
c1 int
c2 boolean
c3 double
c4 string
c5 arrayint
c6 mapint,string
c7 mapstring,string
...
hive select c6 from alltypesparquet;
{1:"x",2:"y"}
and I can easily get k,v just in one row:
hive select c6[1],c6[2] from alltypesparquet;
In Drill, I query like this:
0: jdbc:drill:zk=local select t.c6 from
dfs.`/home/qihuang.zheng/hive_alltypes.parquet` t;
{"map":[{"key":1,"value":"eA=="},{"key":2,"value":"eQ=="}]}
Not only the structure changed, but also String value x,y to eA==,eQ==.
structure: t.c6.map is now an array. so I can't query like : t.c6.key now.
I should :t.c6.map[0].key, But since I should get all key, not the first one.
the solution I can figure now is use flatten:
0: jdbc:drill:zk=local select tb.flat.key,tb.flat.`value` from(select
flatten(t.c6.map) flat from dfs.`/home/qihuang.zheng/hive_alltypes.parquet` t )
tb;
+---------+--------------+
| EXPR$0 | EXPR$1 |
+---------+--------------+
| 1 | [B@2cf5c838 |
| 2 | [B@3c2beb97 |
I looks like so complicate, and now One Row to Two Row, and then I should use
SQL's RowToColumn to make
the result to Only One Row, Complicatedddd too much.
Anyone has good solution? And Why Drill's map structure is different with Hive?
Tks!
qihuang.zheng
