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Posted to user@spark.apache.org by sujeet jog <su...@gmail.com> on 2016/07/21 14:59:15 UTC

Load selected rows with sqlContext in the dataframe

I have a table of size 5GB, and want to load selective rows into dataframe
instead of loading the entire table in memory,


For me memory is a constraint hence , and i would like to peridically load
few set of rows and perform dataframe operations on it,

,
for the "dbtable"  is there a way to perform select * from master_schema
where 'TID' = '100_0';
which can load only this to memory as dataframe .



Currently  I'm using code as below
    val df          =  sqlContext.read .format("jdbc")
                      .option("url", url)
                      .option("dbtable", "master_schema").load()


Thansk,
Sujeet

Re: Load selected rows with sqlContext in the dataframe

Posted by sujeet jog <su...@gmail.com>.

Thanks Todd.

On Thu, Jul 21, 2016 at 9:18 PM, Todd Nist <ts...@gmail.com> wrote:

> You can set the dbtable to this:
>
> .option("dbtable", "(select * from master_schema where 'TID' = '100_0')")
>
> HTH,
>
> Todd
>
>
> On Thu, Jul 21, 2016 at 10:59 AM, sujeet jog <su...@gmail.com> wrote:
>
>> I have a table of size 5GB, and want to load selective rows into
>> dataframe instead of loading the entire table in memory,
>>
>>
>> For me memory is a constraint hence , and i would like to peridically
>> load few set of rows and perform dataframe operations on it,
>>
>> ,
>> for the "dbtable"  is there a way to perform select * from master_schema
>> where 'TID' = '100_0';
>> which can load only this to memory as dataframe .
>>
>>
>>
>> Currently  I'm using code as below
>>     val df          =  sqlContext.read .format("jdbc")
>>                       .option("url", url)
>>                       .option("dbtable", "master_schema").load()
>>
>>
>> Thansk,
>> Sujeet
>>
>
>

Re: Load selected rows with sqlContext in the dataframe

Posted by Todd Nist <ts...@gmail.com>.

You can set the dbtable to this:

.option("dbtable", "(select * from master_schema where 'TID' = '100_0')")

HTH,

Todd


On Thu, Jul 21, 2016 at 10:59 AM, sujeet jog <su...@gmail.com> wrote:

> I have a table of size 5GB, and want to load selective rows into dataframe
> instead of loading the entire table in memory,
>
>
> For me memory is a constraint hence , and i would like to peridically load
> few set of rows and perform dataframe operations on it,
>
> ,
> for the "dbtable"  is there a way to perform select * from master_schema
> where 'TID' = '100_0';
> which can load only this to memory as dataframe .
>
>
>
> Currently  I'm using code as below
>     val df          =  sqlContext.read .format("jdbc")
>                       .option("url", url)
>                       .option("dbtable", "master_schema").load()
>
>
> Thansk,
> Sujeet
>