ODBC连接，在R中获取一个表

Question

Wrestling the whole day with this issue:

I Want to access data on Hadoop (through Hive). And installed the ODBC package.

I'm able to make connection with the server:

con <- dbConnect(odbc:: odbc(), "hadoop") 

And I am able to see the table that I want to get in R:

dblistTables(con, schema= "aacs") 

The output is:

   [1] "dev_1"                  "dev_2"     
   [3] "dev_3"                  "dev_4"

I want to have "dev_4" (in a data frame) in my R environment. I tried:

db_orders <- tbl(con, "dev_4")

But I got an error: Table or view not found. Also the next line lead to nothing.

db_orders <- tbl(con, "aacs.dev_4")

How can I get that data table in my R environment?

EDIT 1

Tried to run the next two things:

result <- dbSendQuery(con, "SELECT * FROM aacs.dev_4")

Received an error: No Space left on device.

Ok, so let's reduce the query then:

result <- dbSendQuery(con, "SELECT * FROM aacs.dev_4 LIMIT 100")

But again, the same error:

Error: <SQL> 'SELECT * FROM aacs.dev_4 limit 100'
  nanodbc/nanodbc.cpp:1587: HY000: [Hortonworks][Hardy] (35) Error from server: error code: '2' error message: 'Error while processing statement: FAILED: Execution Error, return code 2 from org.apache.hadoop.hive.ql.exec.tez.TezTask. Vertex failed, vertexName=Reducer 2, vertexId=vertex_15177720341_0081_2_08, diagnostics=[Task failed, taskId=task_15177723341_0081_2_08_000146, diagnostics=[TaskAttempt 0 failed, info=[Error: FS Error in Child JVM:org.apache.hadoop.fs.FSError: java.io.IOException: No space left on device
    at org.apache.hadoop.fs.RawLocalFileSystem$LocalFSFileOutputStream.write(RawLocalFileSystem.java:261)
    at java.io.BufferedOutputStream.write(BufferedOutputStream.java:122)
    at org.apache.hadoop.fs.FSDataOutputStream$PositionCache.write(FSDataOutputStream.java:58)
    at java.io.DataOutputStream.write(DataOutputStream.java:107)
    at org.apache.tez.runtime.library.common.sort.impl.IFileOutputStream.write(IFil

Anyone an idea how to solve this? It is strange that there is no memory left.. because I have a lot of space (enough to store the data!).

EDIT 2

As @Florian suggested:

data <- dbReadTable(con, "aacs.dev_4") 

Led to the next error:

Error: <SQL> 'SELECT * FROM `aacs.dev_4`'
  nanodbc/nanodbc.cpp:1587: HY000: [Hortonworks][Hardy] (35) Error from server: error code: '2' error message: 'Error while processing statement: FAILED: Execution Error, return code 2 from org.apache.hadoop.hive.ql.exec.tez.TezTask. Vertex failed, vertexName=Reducer 2, vertexId=vertex_1517772023341_0082_1_08, diagnostics=[Task failed, taskId=task_1517772023341_0082_1_08_000236, diagnostics=[TaskAttempt 0 failed, info=[Error: exceptionThrown=org.apache.tez.runtime.library.common.shuffle.orderedgrouped.Shuffle$ShuffleError: error in shuffle in fetcher {Map_4} #10
    at org.apache.tez.runtime.library.common.shuffle.orderedgrouped.Shuffle$RunShuffleCallable.callInternal(Shuffle.java:360)
    at org.apache.tez.runtime.library.common.shuffle.orderedgrouped.Shuffle$RunShuffleCallable.callInternal(Shuffle.java:337)
    at org.apache.tez.common.CallableWithNdc.call(CallableWithNdc.java:36)
    at java.util.concurrent.FutureTask.run(FutureTask.java

Answer 1

Try

x <- dbReadTable(con, "dev_4")

Full working example:

library(DBI)
library(RSQLite)

con <- dbConnect(RSQLite::SQLite(), ":memory:")

dbListTables(con)
dbWriteTable(con, "mtcars", mtcars)
x <- dbReadTable(con, "mtcars")

Hope this helps!

Answer 2

I know what went wrong...

There is an error in the View ("dev_4"). Because when I ran the code:

test <- dbReadTable(con, "dev_3") 

I got the data frame returned. Time to connect with the Data engineer... thanks for you help!

Answer 3

我想你在找

data<- dbGetQuery(con,"SELECT * FROM aacs.dev_4 LIMIT 100")