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Posted to user@hbase.apache.org by Alok Kumar <al...@gmail.com> on 2012/01/20 09:48:02 UTC
Is HBase.Client.Result.getValue(...) and Result.getColumn(...) fetch
actual value from TABLE everytime
Hi All,
I like to know if
HBase.Client.Result.getValue(...) and
Result.getColumn(...) fetch actual value from TABLE everytime
or is it available in Result/ResultScanner already?
--
Alok
Re: Is HBase.Client.Result.getValue(...) and Result.getColumn(...)
fetch actual value from TABLE everytime
Posted by Alok Kumar <al...@gmail.com>.
I could not get any other way/test to quickly know about it.. :)
On Sat, Jan 21, 2012 at 7:48 PM, Alok Kumar <al...@gmail.com> wrote:
> Hi Lars,
>
> Thanks for reply..
> I wanted to know ... Is Column Values are also cached in Result object
> (ie, less number of calls to Hbase table for values)
> or
> It has been fetched at the time when i loop through it with
> 'Col-Family:Col-Name' using
> getValue(..) or getColumn(...) ?
>
> I understand, it is present in Result object from ur reply. Am i correct?
>
> regards,
> Alok
>
>
> On Sat, Jan 21, 2012 at 9:42 AM, lars hofhansl <lh...@yahoo.com>wrote:
>
>> The values are fetched by the operation that returned the Result object
>> and subsequently cached in the Result object.
>> Is that what you were asking?
>>
>>
>> -- Lars
>>
>>
>>
>> ________________________________
>> From: Alok Kumar <al...@gmail.com>
>> To: user@hbase.apache.org
>> Sent: Friday, January 20, 2012 12:48 AM
>> Subject: Is HBase.Client.Result.getValue(...) and Result.getColumn(...)
>> fetch actual value from TABLE everytime
>>
>> Hi All,
>>
>> I like to know if
>>
>> HBase.Client.Result.getValue(...) and
>> Result.getColumn(...) fetch actual value from TABLE everytime
>>
>> or is it available in Result/ResultScanner already?
>>
>>
>> --
>> Alok
>>
>
>
>
> --
> Alok Kumar
>
>
>
--
Alok Kumar
Re: Is HBase.Client.Result.getValue(...) and Result.getColumn(...)
fetch actual value from TABLE everytime
Posted by Doug Meil <do...@explorysmedical.com>.
I think I understand what you're asking now. For background see "scan
attribute selection" in here...
http://hbase.apache.org/book.html#perf.reading
The attributes that are specified in a Scan or Get are transferred to the
client regardless if they are actually used by the client.
On a related note, see the "scan caching" entry in the same chapter (the
equivalent is the fetch-size in JDBC).
On 1/21/12 9:18 AM, "Alok Kumar" <al...@gmail.com> wrote:
>Hi Lars,
>
>Thanks for reply..
>I wanted to know ... Is Column Values are also cached in Result object
>(ie,
>less number of calls to Hbase table for values)
> or
>It has been fetched at the time when i loop through it with
>'Col-Family:Col-Name' using
>getValue(..) or getColumn(...) ?
>
>I understand, it is present in Result object from ur reply. Am i correct?
>
>regards,
>Alok
>
>
>On Sat, Jan 21, 2012 at 9:42 AM, lars hofhansl <lh...@yahoo.com>
>wrote:
>
>> The values are fetched by the operation that returned the Result object
>> and subsequently cached in the Result object.
>> Is that what you were asking?
>>
>>
>> -- Lars
>>
>>
>>
>> ________________________________
>> From: Alok Kumar <al...@gmail.com>
>> To: user@hbase.apache.org
>> Sent: Friday, January 20, 2012 12:48 AM
>> Subject: Is HBase.Client.Result.getValue(...) and Result.getColumn(...)
>> fetch actual value from TABLE everytime
>>
>> Hi All,
>>
>> I like to know if
>>
>> HBase.Client.Result.getValue(...) and
>> Result.getColumn(...) fetch actual value from TABLE everytime
>>
>> or is it available in Result/ResultScanner already?
>>
>>
>> --
>> Alok
>>
>
>
>
>--
>Alok Kumar
Re: Is HBase.Client.Result.getValue(...) and Result.getColumn(...)
fetch actual value from TABLE everytime
Posted by Alok Kumar <al...@gmail.com>.
Hi Lars,
Thanks for reply..
I wanted to know ... Is Column Values are also cached in Result object (ie,
less number of calls to Hbase table for values)
or
It has been fetched at the time when i loop through it with
'Col-Family:Col-Name' using
getValue(..) or getColumn(...) ?
I understand, it is present in Result object from ur reply. Am i correct?
regards,
Alok
On Sat, Jan 21, 2012 at 9:42 AM, lars hofhansl <lh...@yahoo.com> wrote:
> The values are fetched by the operation that returned the Result object
> and subsequently cached in the Result object.
> Is that what you were asking?
>
>
> -- Lars
>
>
>
> ________________________________
> From: Alok Kumar <al...@gmail.com>
> To: user@hbase.apache.org
> Sent: Friday, January 20, 2012 12:48 AM
> Subject: Is HBase.Client.Result.getValue(...) and Result.getColumn(...)
> fetch actual value from TABLE everytime
>
> Hi All,
>
> I like to know if
>
> HBase.Client.Result.getValue(...) and
> Result.getColumn(...) fetch actual value from TABLE everytime
>
> or is it available in Result/ResultScanner already?
>
>
> --
> Alok
>
--
Alok Kumar
Re: Is HBase.Client.Result.getValue(...) and Result.getColumn(...) fetch actual value from TABLE everytime
Posted by lars hofhansl <lh...@yahoo.com>.
The values are fetched by the operation that returned the Result object and subsequently cached in the Result object.
Is that what you were asking?
-- Lars
________________________________
From: Alok Kumar <al...@gmail.com>
To: user@hbase.apache.org
Sent: Friday, January 20, 2012 12:48 AM
Subject: Is HBase.Client.Result.getValue(...) and Result.getColumn(...) fetch actual value from TABLE everytime
Hi All,
I like to know if
HBase.Client.Result.getValue(...) and
Result.getColumn(...) fetch actual value from TABLE everytime
or is it available in Result/ResultScanner already?
--
Alok