cda-client taking long time to write to csv file

[raj4j2ee]

Hi team,
Scala writing to dataframe (9262) to csv taking 8.48 hours. We are seeing the process throwing OOO because of this long running and volume of the tables processed. Please let me know any way we can reduce performance for below line of code
here saveAsSingleFile=true

if (saveAsSingleFile) {
tableDF.coalesce(1).write.option("header", includeColumnNames).option("emptyValue",null).option("nullValue",null).mode(SaveMode.Overwrite).csv(pathToFolderWithCSV)
} else {

  tableDF.write.option("header", includeColumnNames).option("emptyValue","").option("nullValue",null).mode(SaveMode.Overwrite).csv(pathToFolderWithCSV)
}