CODEWITHSUNDEEP
hbaseapache-drill
andrea pagani
andrea pagani

Reputation: 43

Apache Drill empty result when using WHERE clause querying HBase

I am a newbie in Drill and Hbase.
I have installed Hbase 1.2.1 and Drill 1.9.0 both on a embedded (single host) configuration. I have enabled the HBase plugin with default parameters.

I have a table that I manage to connect to and retrieve:

SELECT CONVERT_FROM(row_key, 'UTF8') as key, 
       CAST(fogDecDB.Location.latitude AS FLOAT) as lat  
FROM fogDecDB LIMIT 10;

which gives

+-------------------------------------------------------------------+------------+
|                                key                                |    lat     |
+-------------------------------------------------------------------+------------+
| 00001e14dbf570471418f1c26384637a3154561bfc32062bbb416bedc165841d  | 51.971     |
| 0000c0ad64df90c8feebd4e191272413d01989c997d0e2aec34cf259f3207ddb  | 52.276943  |
| 00023c7cf936bd1933f8b0f690ae3f347d3fd3131278b4e0372d34dde9586b62  | 52.276943  |
| 0003164d842b488a1a0d8572ae06b983ceb3a645f41531acfe4962ad7ede80a2  | 52.276943  |
| 0003bd065e59d03f3907531279579025f49282a3aa1734d1c4d63df891420c58  | 52.1093    |
| 0006963d79ccf3a71f086f77b26a4db7da09a77c8b2c523fc51e04df4087abbd  | 52.1093    |
| 00069cd1f16dde18f4b6944c81015e4f7113ae447c02743a903814c0e64bb2e8  | 52.1093    |
| 00070d2b641fc506be01c4b0b15f102d01b43d34f0b98f054154d20ea1ad7aa1  | 52.1093    |
| 0007fd3e7db369f258173e7d47c13f81e3cbb48ecf446dd6ad4fe49bda2abcf0  | 52.276943  |
| 0009c8836878a0065a617ba066c5c6ba51a9e29d22c81a8df28be40352efd4bf  | 52.1093    |
+-------------------------------------------------------------------+------------+
10 rows selected (0.18 seconds)

The issue is when I add a WHERE statement to perform a kind of selection e.g. only the rows with lat>52.0

I do the following command

enter SELECT CONVERT_FROM(row_key, 'UTF8') as key, 
             CAST(fogDecDB.Location.latitude AS FLOAT) as lat  
      FROM fogDecDB 
      WHERE fogDecDB.Location.latitude>52 
      LIMIT 10;

it gives an empty table - Very weird.

I have tried to CAST also in the WHERE statement the fogDecDB.Location.latitude but same result.

Can anyone please shed some light on the issue. I of course googled a lot with no luck.

Many thanks in advance.

Cheers,

Andrea

Upvotes: 0

Views: 297

Answers (1)

andrea pagani
andrea pagani

Reputation: 43

I have identified the issue and the behavior and the reason for the error:

My HBase schema for that column I am trying to select is actually:

fogDecDB.Location.Latitute with a capital "L"

however it gets somehow identified and properly parsed in the SELECT part of the statement even if it is not correct (Lexicographically/string matching speaking) and in the WHERE part it gets somehow not recognized anymore.

The issue has been reported to the Drill mailing-list.

Upvotes: 2

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