Any progress on this one?
Dudu
From: Aviral Agarwal [mailto:aviral12...@gmail.com]
Sent: Wednesday, June 15, 2016 1:04 PM
To: user@hive.apache.org
Subject: Re: Optimized Hive query
I ok to digging down to the AST Builder class. Can you guys point me to the
right class ?
Meanwhile "ex
I ok to digging down to the AST Builder class. Can you guys point me to the
right class ?
Meanwhile "explain (rewrite | logical | extended) ", all are not able to
flatten even a basic query of the form:
select * from ( select * from ( select c from d) alias_1 ) alias_2
into
select c from d
Tha
> So I was hoping of using internal Hive CBO to somehow change the AST
>generated for the query somehow.
Hive does have an "explain rewrite" but that prints out the query before
CBO runs.
For CBO, you need to dig all the way down to the ASTBuilder class and work
upwards from there.
Perhaps add
representation of the abstract
> syntactic <https://en.wikipedia.org/wiki/Abstract_syntax> structure of source
> code <https://en.wikipedia.org/wiki/Source_code> written in a programming
> language <https://en.wikipedia.org/wiki/Programming_language>.
>
>
>
>
&
_syntax> structure of
source code<https://en.wikipedia.org/wiki/Source_code> written in a programming
language<https://en.wikipedia.org/wiki/Programming_language>.
From: Mich Talebzadeh [mailto:mich.talebza...@gmail.com]
Sent: Tuesday, June 14, 2016 7:58 PM
To: user
Subject: Re: Op
…”)
>
> In no point do we have a “flattened query”
>
>
>
> Dudu
>
>
>
> *From:* Aviral Agarwal [mailto:aviral12...@gmail.com]
> *Sent:* Tuesday, June 14, 2016 10:37 AM
> *To:* user@hive.apache.org
> *Subject:* Re: Optimized Hive query
>
>
>
> Hi,
Subject: Re: Optimized Hive query
Hi,
Thanks for the replies.
I already knew that the optimizer already does that.
My usecase is a bit different though.
I want to display the flattened query back to the user.
So I was hoping of using internal Hive CBO to somehow change the AST generated
for the
I presume the user is concerned with performance?
The whole use case of a CBO is to take care of queries by finding the
optimum access path.
otherwise we would have a RBO as is in the old days of Hive.
If you are in the more recent version of Hive CBO does the job.
However, you may think of mov
Hi,
Thanks for the replies.
I already knew that the optimizer already does that.
My usecase is a bit different though.
I want to display the flattened query back to the user.
So I was hoping of using internal Hive CBO to somehow change the AST
generated for the query somehow.
Thanks,
Aviral
On Tu
> You can see that you get identical execution plans for the nested query
>and the flatten one.
Wasn't that always though. Back when I started with Hive, before Stinger,
it didn't have the identity project remover.
To know if your version has this fix, try looking at
hive> set hive.optimize.rem
ListSink
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|
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+---+--+
From: Aviral Agarwal [mailto:aviral12...@gmail.com]
Sent: Monday, June 13, 2016 7:55 PM
To: user@hive.apache.org
Subject: Optimized Hive query
Hi,
Yes I want to flatten the query.
Also the Insert code is correct.
Thanks,
Aviral Agarwal
On Tue, Jun 14, 2016 at 3:46 AM, Mich Talebzadeh
wrote:
> you want to flatten the query I understand.
>
> create temporary table tmp as select c from d;
>
> INSERT INTO TABLE a
> SELECT c from tmp where
>
you want to flatten the query I understand.
create temporary table tmp as select c from d;
INSERT INTO TABLE a
SELECT c from tmp where
condition
Is the INSERT code correct?
HTH
Dr Mich Talebzadeh
LinkedIn *
https://www.linkedin.com/profile/view?id=AAEWh2gBxianrbJd6zP6AcPCCdOABUrV8Pw
Hi,
I would like to know if there is a way to convert nested hive sub-queries
into optimized queries.
For example :
INSERT INTO TABLE a.b SELECT * FROM ( SELECT c FROM d)
into
INSERT INTO TABLE a.b SELECT c FROM D
This is a simple example but the solution should apply is there were deeper
nesti
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