Home | About | Sematext search-lucene.com search-hadoop.com
 Search Hadoop and all its subprojects:

Switch to Threaded View
Hive, mail # user - Adding comment to a table for columns


Copy link to this message
-
Re: Adding comment to a table for columns
Chunky Gupta 2013-02-21, 13:16
Hi Bejoy,

I checked and didn't find anywhere using extended and formatted
simultaneously to describe table. It is like :-

DESCRIBE [EXTENDED|FORMATTED] table_name[DOT col_name ( [DOT field_name] |
[DOT '$elem$'] | [DOT '$key$'] | [DOT '$value$'] )* ]

Everywhere it says i can use only one at a time.

I tried using both as you suggested and gets this error :-
FAILED: Parse Error: line 1:19 mismatched input 'extended' expecting
Identifier near 'formatted' in specifying table types

If you can please try to remember the exact operation , or if there is any
other way of doing it then please let me know.

Thanks,
Chunky.
On Thu, Feb 21, 2013 at 5:22 PM, <[EMAIL PROTECTED]> wrote:
>
> Hi Gupta
>
> Try out
>
> DESCRIBE EXTENDED FORMATTED <table-name>
>
> I vaguely recall a operation like this.
> Please check hive wiki for the exact syntax.
>
> Regards
> Bejoy KS
>
> Sent from remote device, Please excuse typos
> ________________________________
> From: Chunky Gupta <[EMAIL PROTECTED]>
> Date: Thu, 21 Feb 2013 17:15:37 +0530
> To: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>; <
[EMAIL PROTECTED]>
> ReplyTo: [EMAIL PROTECTED]
> Subject: Re: Adding comment to a table for columns
>
> Hi Bejoy, Bhaskar
>
> I tried using FORMATTED, but it will not give me comments which I have
put while creating table. Its output is like :-
>
> col_name                data_type               comment
> c                        string                  from deserializer
> time                    string                  from deserializer
>
> Thanks,
> Chunky.
>
> On Thu, Feb 21, 2013 at 4:50 PM, <[EMAIL PROTECTED]> wrote:
>>
>> Hi Gupta
>>
>> You can the describe output in a formatted way using
>>
>> DESCRIBE FORMATTED <table name>;
>> Regards
>> Bejoy KS
>>
>> Sent from remote device, Please excuse typos
>> ________________________________
>> From: Chunky Gupta <[EMAIL PROTECTED]>
>> Date: Thu, 21 Feb 2013 16:46:30 +0530
>> To: <[EMAIL PROTECTED]>
>> ReplyTo: [EMAIL PROTECTED]
>> Subject: Adding comment to a table for columns
>>
>> Hi,
>>
>> I am using this syntax to add comments for all columns :-
>>
>> CREATE EXTERNAL TABLE test ( c STRING COMMENT 'Common  class', time
STRING COMMENT 'Common  time', url STRING COMMENT 'Site URL' ) PARTITIONED
BY (dt STRING ) LOCATION 's3://BucketName/'
>>
>> Output of Describe Extended table is like :- (Output is just an example
copied from internet)
>>
>> hive> DESCRIBE EXTENDED table_name;
>>
>> Detailed Table Information Table(tableName:table_name,
dbName:benchmarking, owner:root, createTime:1309480053, lastAccessTime:0,
retention:0, sd:StorageDescriptor(cols:[FieldSchema(name:session_key,
type:string, comment:null), FieldSchema(name:remote_address, type:string,
comment:null), FieldSchema(name:canister_lssn, type:string, comment:null),
FieldSchema(name:canister_session_id, type:bigint, comment:null),
FieldSchema(name:tltsid, type:string, comment:null),
FieldSchema(name:tltuid, type:string, comment:null),
FieldSchema(name:tltvid, type:string, comment:null),
FieldSchema(name:canister_server, type:string, comment:null),
FieldSchema(name:session_timestamp, type:string, comment:null),
FieldSchema(name:session_duration, type:string, comment:null),
FieldSchema(name:hit_count, type:bigint, comment:null),
FieldSchema(name:http_user_agent, type:string, comment:null),
FieldSchema(name:extractid, type:bigint, comment:null),
FieldSchema(name:site_link, type:string, comment:null),
FieldSchema(name:dt, type:string, comment:null), FieldSchema(name:hour,
type:int, comment:null)],
location:hdfs://hadoop2/user/hive/warehouse/benchmarking.db/table_name,
inputFormat:org.apache.hadoop.mapred.SequenceFileInputFormat,
outputFormat:org.apache.hadoop.hive.ql.io.HiveSequenceFileOutputFormat,
compressed:false, numBuckets:-1, serdeInfo:SerDeInfo(name:null,
serializationLib:org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe)
>>
>> Is there any way of getting this detailed comments and column name in
readable format, just like the output of "Describe table_name" ?.