It work only with join with = condition and the left side comes from one table, and the right side comes from another table. You can easily imagine how we implement this with map reduce.
If you can find a good way to do your join in map-reduce, let us know and we might be able to add that to Hive. How many url_patterns do you have? If it's a small number, maybe just inline the url_patterns into the query. Zheng On Wed, Jun 10, 2009 at 12:06 AM, Min Zhou <[email protected]> wrote: > then how about below? > > SELECT > a.subid, a.id, t.url > FROM > tbl t JOIN aux_tbl a ON regexp_like(t.url, a.url_pattern) > WHERE > t.dt='20090609' > AND a.dt='20090609'; > > the udf regexp_like have the same function with rlike, the only difference > between them is one is a prefix operator and the other is a infix operator. > > Thanks, > Min > > > On Wed, Jun 10, 2009 at 2:58 PM, Zheng Shao <[email protected]> wrote: > >> If this does not work, and you have a concrete idea on how to make it >> work, please open a jira and post your idea there. We can start the >> discussion from there. >> >> Zheng >> >> >> On Tue, Jun 9, 2009 at 11:54 PM, Zheng Shao <[email protected]> wrote: >> >>> We only support EQUI-JOIN: join with equal condition. >>> >>> Is it possible to write a UDF: get_pattern(t.url) ? >>> >>> SELECT >>> a.subid, a.id, t.url >>> FROM >>> tbl t JOIN aux_tbl a ON get_pattern(t.url) = a.url_pattern >>> WHERE >>> t.dt='20090609' >>> AND a.dt='20090609'; >>> >>> Zheng >>> >>> >>> On Tue, Jun 9, 2009 at 11:38 PM, Min Zhou <[email protected]> wrote: >>> >>>> I have a query like below, >>>> >>>> SELECT >>>> a.subid, a.id, t.url >>>> FROM >>>> tbl t JOIN aux_tbl a ON t.url rlike a.url_pattern >>>> WHERE >>>> t.dt='20090609' >>>> AND a.dt='20090609'; >>>> >>>> and parser reported 'FAILED: Error in semantic analysis: line 4:xx Both >>>> Left and Right Aliases Encountered in Join url_pattern' >>>> >>>> how can i correct this query? >>>> >>>> Thanks, >>>> Min >>>> -- >>>> My research interests are distributed systems, parallel computing and >>>> bytecode based virtual machine. >>>> >>>> My profile: >>>> http://www.linkedin.com/in/coderplay >>>> My blog: >>>> http://coderplay.javaeye.com >>>> >>> >>> >>> >>> -- >>> Yours, >>> Zheng >>> >> >> >> >> -- >> Yours, >> Zheng >> > > > > -- > My research interests are distributed systems, parallel computing and > bytecode based virtual machine. > > My profile: > http://www.linkedin.com/in/coderplay > My blog: > http://coderplay.javaeye.com > -- Yours, Zheng
