Better in what sense? ... if it is time you are concerned about there are in memory joins.
-Ajo On Wed, Feb 23, 2011 at 3:39 AM, Bejoy Ks <bejoy...@yahoo.com> wrote: > Ajo, > If we have a good number of elements in the comparison set then going > for a table would be beneficial. But in case of a few elements say 5 wont > multiple '=' be better? > > Regards > Bejoy KS > > ------------------------------ > *From:* Ajo Fod <ajo....@gmail.com> > > *To:* user@hive.apache.org > *Sent:* Mon, February 21, 2011 10:04:41 PM > > *Subject:* Re: Database/Schema , INTERVAL and SQL IN usages in Hive > > On using SQL IN ... what would happen if you created a short table with the > enteries in the IN clause and used a "inner join" ? > > -Ajo > > On Mon, Feb 21, 2011 at 7:57 AM, Bejoy Ks <bejoy...@yahoo.com> wrote: > >> Thanks Jov for the quick response >> >> Could you please let me know which is the latest stable version of hive. >> Also how would you find out your hive version from command line? >> >> Regarding the SQL IN I'm also currently using multiple '=' in my jobs, >> but still wanted to know whether there would be some better usage for the >> same apart from this. >> >> >> Regards >> Bejoy KS >> >> >> >> ------------------------------ >> *From:* Jov <zhao6...@gmail.com> >> *To:* user@hive.apache.org >> *Sent:* Mon, February 21, 2011 9:09:34 PM >> *Subject:* Re: Database/Schema , INTERVAL and SQL IN usages in Hive >> >> >> 在 2011-2-21 下午10:54，"Bejoy Ks" <bejoy...@yahoo.com>写道： >> > >> > Hi Experts >> > I'm using hive for a few projects and i found it a great tool in >> hadoop to process end to end structured data. Unfortunately I'm facing a few >> challenges out here as follows >> > >> > Availability of database/schemas in Hive >> > I'm having multiple projects running in hive each having fairly large >> number of tables. With this much tables all together it is looking a bit >> messed up. Is there any option of creating database/schema in Hive so that I >> can maintain the tables in different databases/schemas corresponding to each >> project. >> >> it seems the resent version has already support database ddl,so,you can >> use create database. >> >> > Using INTERVAL >> > I need to replicate a job running in Teradata edw into hive, i'm >> facing a challenge out here.Not able to identify a similar usage >> corresponding to Interval in teradata within hive. Here is the snippet where >> I'm facing the issue >> > *** where 1.seq_id = r4.seq_id and r4.mc_datetime >= (r1.rc_datetime + >> INTERVAL '05' HOUR) >> > In this query how do i replicate the last part in hive ie >> (r1.rc_datetime + INTERVAL '05' HOUR) , where it is adding 5 hours to the >> obtained time stamp rc_datetime. >> > *The where condition is part of a very large query involving multiple >> table joins. >> >> hive do not have date or timestamp data type,all such type is string,but >> you can write your udf to implement similar function >> >> > >> > Using IN >> > How do we replicate the SQL IN function in hive >> > ie *** where R1.seq_id = r4.seq_id and r1.PROCCESS_PHASE IN ( >> 'Production', 'Stage' , 'QA', 'Development') >> > the last part of the query is where i'm facing the challenge >> r1.PROCCESS_PHASE IN ( 'Production', 'Stage' , 'QA', 'Development') >> > *The where condition is part of a very large query involving multiple >> table joins. >> >> you can use or,e.g. >> >> 'x in(1,2)' can be 'x=1 or x=2' >> >> > Please advise. >> > >> > Regards >> > Bejoy KS >> > >> > >> > >> > >> > >> > >> > >> >> > >
