External sorting technique can be used to sort the data that won't fit in memory
One example is External merge sort algorithm
- Sorts chunks of data that fit in RAM
- Merges the sorted chunks together
Merge step can be done in different ways
- Two way merge
- **Pros : ** Reduce number of disk seeks
- **Cons : ** Increase number of passes
- N way merge (Can be used when )
- **Pros : ** Reduce number of passes
- **Cons : ** Increase number of disk seeks