David, I've created https://issues.apache.org/jira/browse/SQOOP-1093 to track the documentation issue. Thanks for bringing this to the community's attention!
-Abe On Wed, Jun 19, 2013 at 4:21 PM, Abraham Elmahrek <[email protected]> wrote: > Hey David, > > With oracle, the BigDecimalSplitter will be used by default for all number > types. > > -Abe > > > On Wed, Jun 19, 2013 at 4:05 PM, David Kincaid <[email protected]>wrote: > >> Abe, the database is Oracle. >> >> >> On Wed, Jun 19, 2013 at 5:48 PM, Abraham Elmahrek <[email protected]>wrote: >> >>> David, >>> >>> What database are you importing from? The description I gave was for >>> datatypes that map to the BigDecimal Splitter. The userguide might be >>> referring to the IntegerSplitter which will add the remainder to the last >>> value. >>> >>> -Abe >>> >>> >>> On Wed, Jun 19, 2013 at 1:23 PM, David Kincaid >>> <[email protected]>wrote: >>> >>>> Thanks. We didn't specify the number of mappers, so it's giving us 4. I >>>> understand your explanation, but it seems to conflict with the Sqoop user >>>> guide ( >>>> http://sqoop.apache.org/docs/1.4.3/SqoopUserGuide.html#_controlling_parallelism >>>> ): >>>> >>>> "When performing parallel imports, Sqoop needs a criterion by which it >>>> can split the workload. Sqoop uses a *splitting column* to split the >>>> workload. By default, Sqoop will identify the primary key column (if >>>> present) in a table and use it as the splitting column. The low and high >>>> values for the splitting column are retrieved from the database, and the >>>> map tasks operate on evenly-sized components of the total range. For >>>> example, if you had a table with a primary key column of id whose >>>> minimum value was 0 and maximum value was 1000, and Sqoop was directed to >>>> use 4 tasks, Sqoop would run four processes which each execute SQL >>>> statements of the form SELECT * FROM sometable WHERE id >= lo AND id < >>>> hi, with (lo, hi) set to (0, 250), (250, 500), (500, 750), and (750, >>>> 1001) in the different tasks." >>>> >>>> >>>> On Wed, Jun 19, 2013 at 3:14 PM, Abraham Elmahrek <[email protected]>wrote: >>>> >>>>> Hey David, >>>>> >>>>> Here's the algorithm: >>>>> Split lengths are defined by (max - min)/(# mappers) and whatever is >>>>> left is tacked on at the end. So in this case, (288272191-2110)/3 = >>>>> 96090027.33... So I'm assuming the .33... is rounded down and split >>>>> lengths >>>>> will be of length 96090027. Sqoop will then create splits with the >>>>> following points: (min) + (range length)*(n). We can see that 2110 + >>>>> 96090027*0 >>>>> = 2110, 2110 + 96090027*1 = 96092137, 2110 + 96090027*2 = 192182164, >>>>> and 2110 + 96090027*3 = 288272191 will be generated based off of this >>>>> algorithm. The last point to be added will be 288272192 because the >>>>> max value is not part of the generated split points. Then sqoop will >>>>> distributed accordingly based off of these points as you've pointed out >>>>> above. >>>>> >>>>> Just to be sure, did you configure sqoop to use 3 mappers? >>>>> >>>>> Hope this helps, >>>>> -Abe >>>>> >>>>> >>>>> On Wed, Jun 19, 2013 at 8:33 AM, David Kincaid <[email protected] >>>>> > wrote: >>>>> >>>>>> We're seeing a strange thing happen with a sqoop import job with the >>>>>> way the key range is getting distributed among the 4 mappers that are >>>>>> running. The minimum key value is 2110 and the maximum value is >>>>>> 288272191. >>>>>> We are getting one mapper that is only getting one record to import. Here >>>>>> is the distribution among the mappers: >>>>>> >>>>>> [2110, 96092137) >>>>>> [96092137, 192182164) >>>>>> [192182164, 288272191) >>>>>> [288272191, 288272192) >>>>>> >>>>>> you can see that the fourth mapper is given a range with only one >>>>>> value in it. Could someone help me understand what is going on? >>>>>> >>>>>> Thanks, >>>>>> >>>>>> Dave >>>>>> >>>>> >>>>> >>>> >>> >> >
