Hi, Rock, The "AND NOT" is an operator, you can use it as follows
"RowID > 50 and not pressure < 3" which is equivalent to "RowID > 50 and pressure >= 3" The rows of a join are numbered from 0 up to N-1 just like with any other table. However, a better strategy might be to include your own "keys". For example, if you have a key column k1 for table 1 and and k2 for table 2, then you can use (k1, k2) as the key for any join between table 1 and table2. With known keys, then you specify which rows to delete based on expressions on the keys. The recommended way of updating data with FastBit is to mark the old rows in inactive and append a new version of the row. John On 1/31/12 9:32 AM, Rock Wang wrote: > Hi John, > > Thanks for the tips, could you elaborate more about "AND NOT", not > sure what you mean? > > I tried with command like: > > ~/apps/bin/ibis -d jdnet -d jdnet_tmp -q "select a.RowID from working > as a, working_tmp as b where a.RowID = b.RowID" -rid -o output.txt > > It didn't produce the rid, but it only produces rid for the following > > ~/apps/bin/ibis -d jdnet -q "select RowID where RowID > 0" -o > output.txt -rid -v 1 > > do you have any suggestions what would be the best way to update some > records in fasitbit? > > Thanks, > Rock > > > On Mon, Jan 30, 2012 at 9:51 PM, John Wu <[email protected] > <mailto:[email protected]>> wrote: > > Hi, Rock, > > To get ibis.cpp to print the RIDs, please use option '-output > filename' with option '-rid'. This will output the selection results > along with the RIDs. > > For the results of joins, you will need to write them to disk and them > use ibis.cpp. Alternatively, you might consider queries involve "AND > NOT" (which is commonly refer to as logical minus). > > Good luck. > > John > > > > On 1/30/12 5:15 PM, Rock Wang wrote: > > Hi John, > > > > With command ibis -y to yank rows, it accepts a file with a list of > > row ids? Do you know how can I get the id of row from fastbit? > > > > For instance, I need upsert a set of data record, I planed to > join two > > partitions to get existing rows, delete them from working partition. > > But how can I get the row number which I can select from the join? > > > > > > Thanks, > > Rock > > _______________________________________________ FastBit-users mailing list [email protected] https://hpcrdm.lbl.gov/cgi-bin/mailman/listinfo/fastbit-users
