I am not sure now what the schema was set to when I ran that example.
Currently I am getting a different error when I set the schema to
json_click:
0: jdbc:drill:> use MFS.json_click;
+------------+------------+
| ok | summary |
+------------+------------+
| true | Default schema changed to 'MFS.json_click' |
+------------+------------+
1 row selected (0.326 seconds)
0: jdbc:drill:> select * from MFS.json_click.`mobile.json` limit 2;
+------------+------------+------------+------------+----------------+------------+
| trans_id | datestamp | timestamp | user_info | marketing_info |
trans_info |
+------------+------------+------------+------------+----------------+------------+
| 0 | 07/31/2013 | 11:54:24 |
{"cust_id":31,"device":"IOS5","state":"ms"} |
{"camp_id":1,"searchwords":["no","kiss","ever"]} | {"prod_id":[6], |
| 1 | 06/12/2013 | 11:27:12 |
{"cust_id":0,"device":"IOS5","state":"wa"} |
{"camp_id":3,"searchwords":["you"]} | {"prod_id":[93],"purch_flag": |
+------------+------------+------------+------------+----------------+------------+
2 rows selected (0.439 seconds)
0: jdbc:drill:> create table mobile as select * from
MFS.json_click.`mobile.json` limit 2;
+------------+------------+
| ok | summary |
+------------+------------+
| false | Table 'mobile' already exists. |
+------------+------------+
1 row selected (0.144 seconds)
0: jdbc:drill:> create table mobile2 as select * from
MFS.json_click.`mobile.json` limit 2;
Query failed: Screen received stop request sent. null
[72d50e2d-2072-428a-96f4-e7b1debdc2a2]
Error: exception while executing query: Failure while trying to get next
result batch. (state=,code=0)
On Mon, Aug 11, 2014 at 11:49 AM, Steven Phillips <[email protected]>
wrote:
> For question 4, what is the current schema?
>
>
> On Mon, Aug 11, 2014 at 10:57 AM, Bob Rumsby <[email protected]> wrote:
>
>> We talked to Rahul about this last week, and we think that the term
>> *schema* is overloaded and misleading for several reasons:
>>
>> 1. The meaning of the term, generally speaking, depends on the
>> context.
>> 2. A *schema* usually refers to the type and structure of data in a
>> data source, but Drill operates on data that is "schema-less" or
>> "self-describing."
>> 3. We have commands that refer to schemas, workspaces, file systems,
>> and databases interchangeably.
>> 4. A *schema* in the relational database world is a namespace within
>> a single physical database. Drill does not use the term in this way.
>>
>>
>> Below are some specific examples where the use of the term *schema* does
>> not seem appropriate or accurate. It's a little bit tricky to explain
>> clearly. Please let me and Bridget know if you think we should try to
>> change the terminology, and we'll open a Jira.
>>
>> 1. Does it make sense to set a *workspace* or a *database* name with the
>> USE command and have it be called the "default schema"?
>>
>> 0: jdbc:drill:> use hive.`default`;
>>
>> +------------+------------+
>>
>> | ok | summary |
>>
>> +------------+------------+
>>
>> | true | Default schema changed to 'hive.default' |
>>
>> +------------+------------+
>>
>> 1 row selected (0.113 seconds)
>>
>> 2. The SHOW DATABASES command returns a list of "schemas" not databases?
>>
>>
>> 0: jdbc:drill:> show databases;
>>
>> +-------------+
>>
>> | SCHEMA_NAME |
>>
>> +-------------+
>>
>> | hive.default |
>>
>> | dfs.default |
>>
>> ....
>>
>>
>> 3. The SHOW SCHEMAS command returns the same list, really a list of
>> workspaces and databases (workspaces for file systems, databases for Hive
>> and HBase):
>>
>> 0: jdbc:drill:> show schemas;
>>
>> +-------------+
>>
>> | SCHEMA_NAME |
>>
>> +-------------+
>>
>> | hive.default |
>>
>> | dfs.default |
>>
>> | dfs.root |
>>
>> | dfs.tmp |
>>
>> | sys |
>>
>> | MFS.default |
>>
>> | MFS.json_click |
>>
>> | lab.default |
>>
>> | lab.root |
>>
>> | lab.views |
>>
>> | lab.clicks |
>>
>> | hbase |
>>
>> | INFORMATION_SCHEMA |
>>
>> +-------------+
>>
>> 13 rows selected (0.114 seconds)
>>
>>
>> 4. What is a "Drill schema" versus a "non-Drill schema"? This non-Drill
>> schema appears in the show schemas list.
>>
>>
>> 0: jdbc:drill:> create table mobile as select * from
>> MFS.json_click.`mobile.json` limit 2;
>>
>> +------------+------------+
>>
>> | ok | summary |
>>
>> +------------+------------+
>>
>> | false | Error: Current schema is not a Drill schema. Can't create
>> new relations (tables or views) in non-Drill schemas. |
>>
>> +------------+------------+
>>
>> 1 row selected (0.086 seconds)
>>
>> 0: jdbc:drill:> show schemas;
>>
>> +-------------+
>>
>> | SCHEMA_NAME |
>>
>> +-------------+
>>
>> | hive.default |
>>
>> | dfs.default |
>>
>> | dfs.root |
>>
>> | dfs.tmp |
>>
>> | sys |
>>
>> | MFS.default |
>>
>> | MFS.json_click |
>>
>> ....
>>
>>
>
>
> --
> Steven Phillips
> Software Engineer
>
> mapr.com
>
