How to use collections inside foreach block

[Madabhattula Rajesh Kumar]

Hi,

I have a below query. Please help me to solve this

I have a 20000 ids. I want to join these ids to table. This table contains
some blob data. So i can not join these 2000 ids to this table in one step.

I'm planning to join this table in a chunks. For example, each step I will
join 5000 ids.

Below code is not working. I'm not able to add result to ListBuffer. Result
s giving always ZERO

*Code Block :-*

var listOfIds is a ListBuffer with 20000 records

listOfIds.grouped(5000).foreach { x =>
{
var v1 = new ListBuffer[String]()
val r = sc.parallelize(x).toDF()
r.registerTempTable("r")
var result = sqlContext.sql("SELECT r.id, t.data from r, t where r.id = t.id
")
     result.foreach{ y =>
     {
         v1 += y
      }
}
println(" SIZE OF V1 === "+ v1.size)  ==>

*THIS VALUE PRINTING AS ZERO*

*// Save v1 values to other db*
}

Please help me on this.

Regards,
Rajesh