I have created a table:
DROP TABLE IF EXISTS sampleout;
CREATE EXTERNAL TABLE sampleout(
id bigint,
LNG FLOAT,
LAT FLOAT,
GMTDateTime TIMESTAMP,
calculatedcolumn FLOAT
)
ROW FORMAT DELIMITED FIELDS TERMINATED BY ','
STORED AS TEXTFILE LOCATION 'wasb://sampleout@xxxxxx.blob.core.windows.net/';
I then got a success from this query:
INSERT into TABLE sampleout select *, 0 as calculatedcolumn from sampletable
sampleout
is the same as sampletable
except for the extra column calculatedcolumn
. After the successful insert, I opened the blob storage and opened the text file to verify the data is in the specified textfile location.
However...
select * from sampleout limit 10
returns the following error:
Logging initialized using configuration in file:/C:/apps/dist/hive-0.13.0.2.1.12.1-0003/conf/hive-log4j.properties
SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/C:/apps/dist/hadoop-2.4.0.2.1.12.1-0003/share/hadoop/common/lib/slf4j-log4j12-1.7.5.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/C:/apps/dist/hbase-0.98.0.2.1.12.1-0003-hadoop2/lib/slf4j-log4j12-1.6.4.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
SLF4J: Actual binding is of type [org.slf4j.impl.Log4jLoggerFactory]
OK
Failed with exception java.io.IOException:java.io.IOException: Not a file: wasb://sampleout@xxxxxx.blob.core.windows.net/hive
Time taken: 3.032 seconds
how is it that I can successfully insert, but cannot select from the table? Note that the error shows '/hive' added to the textfile location specified in the create.
Basically, do not put the TEXTFILE LOCATION at the root. Even though it is blob storage (no true folders), the structure needed by HDFS or something else wants you to use at least one sub folder in the location.
Moving from
wasb://sampleout@xxxxxx.blob.core.windows.net/
to
wasb://sampleout@xxxxxx.blob.core.windows.net/somefolder/
fixed the issue. Credit: https://stackoverflow.com/users/4951010/andrew-moll