Hi, community.
There was a misunderstanding in my last writing, please ignore it. Thanks.
------------------------------
B. Regards,
Edward yoon @ NHN, corp.
Home : http://www.udanax.org> From: [EMAIL PROTECTED]> To:
hadoop-dev@lucene.apache.org> Subject: Relational Algrebra Operators on hbase
shell.> Date: Mon, 5 Nov 2007 23:14:01 +0000> > > > One last thing, hbase shell
(relational) operators running mapreduce jobs begins to impinge on PIG
territory. We should be careful and avoid overlap/duplicating work. Would it
make sense doing further operators as PIG user defined functions? (I suppose
we'll be able to tell better after PIG-6, the hbase load/store, is done.
Smile).> > I don't think so.> It's just a relational algebra basics.> No these
works, no SQL-like HQL, RDF, Matrix works.> What is an overlapping character?>
I need the exact explain.> > Also, If Pig has time to discuss matrix operations
or linear systems, > Can i said "No, it's a hbase shell territory." ??> > I
feel stuffy becuase i'm just going round in circles discussing the plans of
shell operator on wiki. > (almost for the past two months) > > I bet my name on
shell works and Other members,too.> At least, I have rights to make it.> > Any
advice are welcome.> > Edward J. Yoon,> Thanks.>
------------------------------> B. Regards,> Edward yoon @ NHN, corp.> Home :
http://www.udanax.org> > > > Date: Mon, 5 Nov 2007 14:04:51 -0800> > From:
[EMAIL PROTECTED]> > To: hadoop-dev@lucene.apache.org> > Subject: [jira]
Commented: (HADOOP-1608) [Hbase Shell] Relational Algrebra Operators> >> >> > [
https://issues.apache.org/jira/browse/HADOOP-1608?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#action_12540287
]> >> > stack commented on HADOOP-1608:> > -------------------------------> >>
> Edward:> >> > I do not understand what you mean by the following in your
02/Nov/07 06:09 PM comment: "I'll implement relational algebra operators to the
tentative language and HQL by Sub-Tasks List sequence."> >> > In
org.apache.hadoop.hbase.shell.algebra, test for output table presence and
creation if missing is duplicated code in Selection, Projection,
DuplicateTable, etc. I tried to move this duplicated code back up into the
RelationalOperation class as a utility but noticed then if table already
exists, we don't call initJob because we return early (See end of the getConf
in DuplicateTable for example). Is running one of these operators a second
time, after table has been created, a problem? Have you tried it?> >> > I did
not have a mapreduce cluster running and so the last line hung for ever (You
should add to help need for a mapreduce cluster).> > {code}> > Hbase> aaa =
table('y');> > Hbase> aaa;> > Syntax error : Type 'help;' for usage.Message :
Encountered ";" at line 1, column 5.> > Hbase> show aaa;> > Missing parameters.
Please check 'Show' syntax> > Hbase> bbb = group aaa by ('x'); Hbase> save bbb
into table ('a');> > {code}> >> > Note, it would be nice if you entered a
variable name only if you got a description of the variable content or perhaps
doing 'show VARIABLE_NAME' output some kind of description.> >> > I then
started up a cluster and did the simplest of operations:> > {code}> > Hbase>
aaa = table('x');> > Hbase> save aaa into table(aaaaaa);> > 07/11/05 21:26:57
WARN mapred.JobClient: No job jar file set. User classes may not be found. See
JobConf(Class) or JobConf#setJar(String).Job job_200711052125_0001 is still
running........Job failed.> > {code}> >> > Job failed because of 'Caused by:
java.lang.ClassNotFoundException: org.apache.hadoop.hbase.mapred.TableSplit'.
How do you run on a cluster Edward? Do you copy the hbase jar into the hadoop
lib dir all over the cluster? Does HADOOP-1622 help here?> >> > On job failure,
should the table be removed? Currently, I have a new table 'aaaaaa' with
nothing in it.> >> > The output of Group, Selection, etc. is saved to an
'output' table?> >> > It would be good if we could get into the help listing
somewhere the operators and types of conditions allowed on selection (>, > >
One last thing, hbase shell (relational) operators running mapreduce jobs
begins to impinge on PIG territory. We should be careful and avoid
overlap/duplicating work. Would it make sense doing further operators as PIG
user defined functions? (I suppose we'll be able to tell better after PIG-6,
the hbase load/store, is done. Smile).> >> > Otherwise, patch looks good
Edward.> >> >> >> >> >> >> [Hbase Shell] Relational Algrebra Operators> >>
-------------------------------------------> >>> >> Key: HADOOP-1608> >> URL:
https://issues.apache.org/jira/browse/HADOOP-1608> >> Project: Hadoop> >> Issue
Type: Improvement> >> Components: contrib/hbase> >> Affects Versions: 0.14.1>
>> Environment: All environments> >> Reporter: Edward Yoon> >> Priority: Minor>
>> Fix For: 0.16.0> >>> >> Attachments: patch_v01.txt, patch_v02.txt,
patch_v03.txt, patch_v04.txt, patch_v05.txt, patch_v06.txt, patch_v07.txt,
patch_v08.txt, patch_v09.txt, patch_v10.txt, patch_v11.txt, patch_v12.txt,
patch_v13.txt, patch_v14.txt, patch_v15.txt> >>> >>> >> Development of
relational algebra operators has begun.> >> * Projection> >> ** selects a
subset of the columnfamilies of a relation> >> ** Result = π ~column_list~
(Relation)> >> {code}> >> Hbase> Result =
Relation.Projection('year','legnth');> >> Hbase> save Result into
table('result');> >> {code}> >> * Selection> >> ** See : HADOOP-2003 issue's
description> >> {code}> >> Hbase> Result = Relation.Selection(length> 100 and
studioName = 'Fox');> >> Hbase> save Result into table('result');> >> {code}>
>> * Group> >> ** more details about 'GROUP' operation will be handled in
HADOOP-1658 issue.> >> * θ Join> >> ** The join of two relations R1(A ~1~,A
~2~,...,A ~n~) and R2(B ~1~,B ~2~,...,B ~m~) is a relation with degree k=n+m
and attributes (A ~1~,A ~2~,...,A ~n~, B ~1~,B ~2~,...,B ~m~) that satisfy the
join condition> >> {code}> >> Hbase> R1 = table('movieLog_table');> >> Hbase>
R2 = table('personInfo_table');> >> Hbase> Result = R1.join(R1.producer: =
R2.ROW) and R2;> >> or Result = R1.join(R1.actor:hero = R2.Row) and R2;> >> or
Result = R1.join(R1.actor:hero = R2.Row and R1.studioName = 'Fox' and
R2.occupation = 'singer') and R2;> >> {code}> >> > --> > This message is
automatically generated by JIRA.> > -> > You can reply to this email to add a
comment to the issue online.> >> >
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