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mechatroner / RBQL

🦜RBQL - Rainbow Query Language: SQL-like query engine for (not only) CSV file processing. Supports SQL queries with Python and JavaScript expressions.
https://rbql.org
MIT License
281 stars 13 forks source link

JOIN on NR #10

Closed peheje closed 5 years ago

peheje commented 5 years ago

I would like to join two tables on the their NR column.

select * join <filepath> ON aNR == bNR does not work I get error:

Invalid join syntax. Must be: "<JOIN> /path/to/B/table on a<i> == b<j>"

mechatroner commented 5 years ago

I like the idea. For some reason I never though about this myself. I think this can be implemented as "SequentialMap" which would be more efficient than standard "HashJoinMap" and would avoid keeping the join B table in memory.

mechatroner commented 5 years ago

Join on NR is now supported in the master branch. But it will take some time to release it to the apps. Current implementation is not optimal: it uses the default HashJoinMap, instead of SequentialMap.