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Hive >> mail # user >> Issue with Hive and table with lots of column

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Re: Issue with Hive and table with lots of column
Ok here are the problem(s). Thrift has frame size limits, thrift has to
buffer rows into memory.

Hove thrift has a heap size, it needs to big in this case.

Your client needs a big heap size as well.

The way to do this query if it is possible may be turning row lateral,
potwntially by treating it as a list, it will make queries on it awkward.

Good luck

On Thursday, January 30, 2014, Stephen Sprague <[EMAIL PROTECTED]> wrote:
> oh. thinking some more about this i forgot to ask some other basic
> a) what storage format are you using for the table (text, sequence,
rcfile, orc or custom)?   "show create table <table>" would yield that.
> b) what command is causing the stack trace?
> my thinking here is rcfile and orc are column based (i think) and if you
don't select all the columns that could very well limit the size of the
"row" being returned and hence the size of the internal ArrayList.  OTOH,
if you're using "select *", um, you have my sympathies. :)
> On Thu, Jan 30, 2014 at 11:33 AM, Stephen Sprague <[EMAIL PROTECTED]>
> thanks for the information. Up-to-date hive. Cluster on the smallish
side. And, well, sure looks like a memory issue. :)  rather than an
inherent hive limitation that is.
> So.  I can only speak as a user (ie. not a hive developer) but what i'd
be interested in knowing next is is this via running hive in local mode,
correct? (eg. not through hiveserver1/2).  And it looks like it boinks on
array processing which i assume to be internal code arrays and not hive
data arrays - your 15K columns are all scalar/simple types, correct?  Its
clearly fetching results and looks be trying to store them in a java array
- and not just one row but a *set* of rows (ArrayList)
> two things to try.
> 1. boost the heap-size. try 8192. And I don't know if HADOOP_HEAPSIZE is
the controller of that. I woulda hoped it was called something like
"HIVE_HEAPSIZE". :)  Anyway, can't hurt to try.
> 2. trim down the number of columns and see where the breaking point is.
is it 10K? is it 5K?   The idea is to confirm its _the number of columns_
that is causing the memory to blow and not some other artifact unbeknownst
to us.
> 3. Google around the Hive namespace for something that might limit or
otherwise control the number of rows stored at once in Hive's internal
buffer. I snoop around too.
> That's all i got for now and maybe we'll get lucky and someone on this
list will know something or another about this. :)
> cheers,
> Stephen.
> On Thu, Jan 30, 2014 at 2:32 AM, David Gayou <[EMAIL PROTECTED]> wrote:
> We are using the Hive 0.12.0, but it doesn't work better on hive 0.11.0
or hive 0.10.0
> Our hadoop version is 1.1.2.
> Our cluster is 1 master + 4 slaves with 1 dual core xeon CPU (with
hyperthreading so 4 cores per machine) + 16Gb Ram each
> The error message i get is :
> 2014-01-29 12:41:09,086 ERROR thrift.ProcessFunction
(ProcessFunction.java:process(41)) - Internal error processing FetchResults
> java.lang.OutOfMemoryError: Java heap space
>         at java.util.Arrays.copyOf(Arrays.java:2734)
>         at java.util.ArrayList.ensureCapacity(ArrayList.java:167)
>         at java.util.ArrayList.add(ArrayList.java:351)
>         at org.apache.hive.service.cli.Row.<init>(Row.java:47)
>         at org.apache.hive.service.cli.RowSet.addRow(RowSet.java:61)
>         at
>         at
>         at
>         at
>         at
>         at

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