Hi, Andreas, The code for treating blank fields in CSV files as NULL values have been checked into the SVN repository. For example, the last two fields of the first of the two following lines will be treated as NULL values when you tell ardea.cpp that they are numerical values,
school, , school, 1, 130000 For string-valued columns, there is some ambiguity as whether you intend to have a blank string or it is something missing. For the moment, we treat a blank string as as the user really wanted a blank string -- i.e., not NULL. You should be able to get the night snapshot at <https://codeforge.lbl.gov/snapshots.php?group_id=44>. Please let us know how it works out for you if you do have a chance to try it. John PS: The nightly snapshot is built around 2-3 AM Pacific Time (USA) daily. To be sure the snapshot you've downloaded has the new code, please take a look at the top of file ChangeLog. It should include some entries from 2009-12-23. On 12/23/2009 5:06 AM, Andreas Streichardt wrote: > Hi, > > i am wondering how (and if?) Fastbit handles NULL values. I only found a few > references in the documentation about NULL values. > > This is one of them: > > https://sdm.lbl.gov/fastbit/doc/html/classibis_1_1tafel.html#8bfb87b836ec0e5b10a6f0c8a32fa6e6 > > To me that sounds as if the NULL value for a "int" should be 2^31-1. I can > load these values via ardea. However when querying via ibis: How are these > null values handled? > > /home/mop/fastbit/bin/ibis -d null_test -n -q "SELECT x WHERE 1=1" > x (with counts) > 2147483647, 1 > > This is fine. > > /home/mop/fastbit/bin/ibis -d null_test -n -q "SELECT COUNT(x) WHERE 1=1" > tableSelect -- select(COUNT(x), 1=1) on table T-null_test produced a table > with 1 row and 1 column > tableSelect -- the result table (1 x 1) for "SELECT COUNT(x) FROM T-null_test > WHERE 1=1" > 1 > > I would fastbit to omit the NULL value here. Same for AVG() and the other > aggregate functions. Are NULL values even implemented or am i badly > misunderstanding something here? :S > > Kind regards, > > Andreas Streichardt > _______________________________________________ > FastBit-users mailing list > [email protected] > https://hpcrdm.lbl.gov/cgi-bin/mailman/listinfo/fastbit-users _______________________________________________ FastBit-users mailing list [email protected] https://hpcrdm.lbl.gov/cgi-bin/mailman/listinfo/fastbit-users
