Hi, Jan,
I am actually expecting the names passed to ibis::quaere::select to be
fully qualified names, i.e., "data1.a", not "a".
Did you skipped the from clause? There was a little bug in the
implementation of ibis::fromClause used for name look up. This little
problem was fixed yesterday afternoon. You can get the fix from the
latest SVN repository.
John
On 6/24/2010 8:31 AM, Krivanek, Jan wrote:
> Hi John,
>
> Thank you for update to this topic. I checked out newest code and tried
> my example that wasn't working. Now I seem to be able to join two
> partitions, and then dump resulting data, but only in case if I do not
> fully specify the column name with name of the partition.
> (So if I change the codeline "colnames.push_back("data1.a");" below to
> "colnames.push_back("a");" then I am able to get the results, if I leave
> it as is, then the final select fail with exception somewhere inside the
> code). Anyway, this now doesn't seem to be a issue blocking me from
> performing joins.
>
> Thanks
> Jan
>
> -----Original Message-----
> From: K. John Wu [mailto:[email protected]]
> Sent: Wednesday, June 23, 2010 7:07 AM
> To: Krivanek, Jan
> Cc: FastBit Users
> Subject: Re: [FastBit-users] Unable to dump results of (natural) join
> operation
>
> Hi, Jan,
>
> A number of updates to the join code has been checked into the SVN
> repository. Please take a look and let us know if the problem you've
> observed is fixed.
>
> John
>
> On 6/12/2010 2:35 PM, Krivanek, Jan wrote:
>> Hi John,
>>
>> Thank you for your quick reply and information that fix for this
> should
>> be available soon. I must admit that I am a little bit confused now -
>> does it mean that only the naming of column caused the problem? I
>> experienced this also for using the name of column without specifying
>> table name (I tried to debug it a little bit and found some problem in
>> fillEquiJoinTable which checked for validity of passed parameters
>> indicating count of rows in each table satisfying join condition, but
> I
>> am not at my PC now, so I can provide more info after weekend if
>> needed).
>> Also in code I found that there are probably several ways how to
> perform
>> joins - using classes for ibis::jNatural, or ibis::jRange (which is
> not
>> implemented yet), or there are some join methods in ibis::part or
>> ibis::query classes - is there any recommended way how to perform
> joins
>> (for later grouping and sorting of joined results)?
>>
>> Great thanks for your time
>> Jan
>>
>> -----Original Message-----
>> From: K. John Wu [mailto:[email protected]]
>> Sent: Friday, June 11, 2010 7:33 PM
>> To: FastBit Users
>> Cc: Krivanek, Jan
>> Subject: Re: [FastBit-users] Unable to dump results of (natural) join
>> operation
>>
>> Hi, Jan,
>>
>> I have just came across this problem as well and am in the process of
>> fixing it. The root cause is that many functions in FastBit are still
>> using the older way of looking up columns and unable to locate columns
>> named in the format 'data1.a'. The fix for this particular problem is
>> already in-place, however, I am in the process of changing something
>> else, which might take a day or two to complete. I will let you know
>> as soon as I am comfortable that I have not broken things with my
>> latest changes...
>>
>> Thanks for your patience.
>>
>> John
>>
>>
>> On 6/11/2010 2:10 AM, Krivanek, Jan wrote:
>>> I have following two partitions:
>>>
>>> ibis::part: data1 (ardea -d data/data1 -m a:int, b:int -t data1.csv)
>>> with 18 rows, 2 columns
>>>
>>> Column list:
>>>
>>> a: (INT) [1.79769e+308, -1.79769e+308]
>>>
>>> b: (INT) [1.79769e+308, -1.79769e+308]
>>>
>>> ibis::part: data2 (ardea -d data/data2 -m c:int, d:int -t data2.csv)
>>> with 18 rows, 2 columns
>>>
>>> Column list:
>>>
>>> a: (INT) [1.79769e+308, -1.79769e+308]
>>>
>>> d: (INT) [1.79769e+308, -1.79769e+308]
>>>
>>> And I am trying to find a way how to join them and dump results. I
>> used
>>> the following code:
>>>
>>> //create the partitions
>>>
>>> ibis::part *tbl1 = new ibis::part("data1");
>>>
>>> ibis::part *tbl2 = new ibis::part("data2");
>>>
>>> //create the join
>>>
>>> ibis::jNatural *jn = new ibis::jNatural(*tbl1, *tbl2, "a", "b< 8",
> "d
>>>
>>> 4");
>>>
>>> //process the join
>>>
>>> int numRows = jn->count();
>>>
>>> //select the result
>>>
>>> std::vector<const char*> colnames = std::vector<const char*>();
>>>
>>> colnames.push_back("data1.a");
>>>
>>> ibis::table *resultTable = jn->select(colnames);
>>>
>>> //dump the results to cout
>>>
>>> resultTable->dump(std::cout);
>>>
>>> The join is created and processed correctly (I can see the number of
>>> resulting records, which is correct), but selection of the result
>>> returns NULL pointer (with warning "join::fillEquiJoinTable can not
>>> proceed due to invalid arguments"). Below I copy the log output when
>>> calling select method.
>>>
>>> select data1.a FROM From data1 Join data2 Using(a) Where ... -- start
>>> timer ...
>>>
>>> select data1.a FROM From data1 Join data2 Using(a) Where ... -- found
>> 1
>>> column from data1 and 0 column from data2
>>>
>>> column[data1.a](INT)::selectValuesT -- selecting 15 out of 18 values
>>> from ./data/data1\a
>>>
>>> part[data1]::accessHint -- nRows=18, selected=15, #pages=0, first
>>> page=0, last page=0, hint=MMAP_LARGE_FILES
>>>
>>> column[data1.a](INT)::selectValuesT -- got 15 values (15 wanted) from
>> an
>>> in-memory version of file ./data/data1\a as int
>>>
>>> column[data1.a](INT)::selectInts -- retrieving 15 integers took 0
>>> sec(CPU), 0.000108394 sec(elapsed)
>>>
>>> Warning -- join::fillEquiJoinTable can not proceed due to invalid
>> arguments
>>>
>>> select data1.a FROM From data1 Join data2 Using(a) Where ... --
>>> duration: 0.001 sec(CPU), 0.000752051 sec(elapsed)
>>>
>>> I will appreciate any hint on what I am doing wrong, or what are the
>>> best practices to perform joins.
>>>
>>> Regards
>>>
>>> Jan Krivanek
>>>
>>>
>>>
>>> _______________________________________________
>>> FastBit-users mailing list
>>> [email protected]
>>> https://hpcrdm.lbl.gov/cgi-bin/mailman/listinfo/fastbit-users
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