SOLR 7.0 DIH out of memory issue with sqlserver

[Tanya Bompi]

Hi,
  I have the SOLR 7.0 setup with the DataImportHandler connecting to the
sql server db. I keep getting OutOfMemory: Java Heap Space when doing a
full import. The size of the records is around 3 million so not very huge.
I tried the following steps and nothing helped thus far.

1. Setting the "responseBuffering=adaptive;selectMethod=Cursor" in the jdbc
connection string.
2. Setting the batchSize="-1" which hasnt helped
3. Increasing the heap size at solr startup by issuing the command \solr
start -m 1024m -p 8983
Increasing the heap size further doesnt start SOLR instance itself.

I am wondering what could be causing the issue and how to resolve this.
Below is the data-config :

<dataConfig>
  <dataSource type="JdbcDataSource"
              driver="com.microsoft.sqlserver.jdbc.SQLServerDriver"

url="jdbc:sqlserver://SQL10;IntegratedSecurity=True;databaseName=SnapshotData;responseBuffering=adaptive;selectMethod=Cursor"

  user="yyyy"
              />
  <document>

Thanks,
Tanya