NTile

🔷 NTile (Bucket Distribution)

🔍 Definition

NTile is used for:

➡️ Divide data into each group (partition)
➡️ Into several buckets (groups) evenly
➡️ Based on order (sorted data)

👉 Similar:

Divide data into Top 3 groups , Quartile , Percentile group

⚙️ Parameter

🎯 N (Bucket)

Determine the number of buckets
Example:
- N = 2 → 2 groups
- N = 3 → 3 groups
- N = 4 → quartile

📥 Input & 📤 Output

Input

All fields from the previous process

Output

All input fields
➕ new fields:
```
bucket
```

➕ Additional fields:

Old fields with postfix_new

🧠 How it works

Data is partitioned (usually using GroupBy)
Data sorted (ascending / descending)
Divided into N buckets evenly

📊 Example

The following sample data contains three fields: emp_name, dealer_id, and sales.

    emp_name        dealer_id   sales
    ---------------------------------
    Kameko French   2           16233
    Ursa George     3           15427
    Ferris Brown    1           19745
    Noel Meyer      1           19745
    Abel Kim        3           12369
    Raphael Hull    1           8227
    Jack Salazar    1           9710
    May Stout       3           9308
    Haviva Montoya  2           9308

Group And Sort

    Grouped Field       :dealer_id
    Sorted Field        :sales (ascending)

Processed with NTile, partitioned by dealer_id, ordered by sales, and using parameter :

The output of NTile Buffer (field emp_name_new,dealer_id_new,sales_new, bucket) :

    emp_name_new    dealer_id_new   sales_new   bucket
    --------------------------------------------------
    Raphael Hull 	1               8227.0      1
    Jack Salazar 	1               9710.0      1
    Ferris Brown 	1               19745.0     2
    Noel Meyer   	1               19745.0     3
    Haviva Montoya	2               9308.0      1
    Kameko French	2               16233.0     2
    May Stout    	3               9308.0      1
    Abel Kim     	3               12369.0     2
    Ursa George  	3               15427.0     3

💡 Important Note:

The useful output fields from this buffer function are the grouped fields and new fields. Add a Transformator (

) assembly afterward to select these fields.

💡 Important Insights

1. Used for Analysis

✔ Data segmentation
✔ Class division (low, medium, high)
✔ Distribution analysis

3. Real Examples

🎯 Case:

Customer segmentation based on sales

Bucket 1 → Low spender
Bucket 2 → Medium
Bucket 3 → High spender

Below is a sample workflow demonstrating the NTile process :

Description of Workflow : NTileProcess

Flow of Data Processing :

Hfs_source_1 :
HFS Source Hfs_source_1 reads flat file HDFS with properties :

Input Path	:	Arg[0]
File Type	:	Hfs
Combine Input	:	false
Fields in Lower Case	:	false
Delimiter	:

Transformator_1 :
Transformator Transformator_1 transforms the output of 'Hfs_source_1' using the following transfromation function(s)

Input Field	Operation	Output Field	Type
line	RegexSplitter(Splitter=\|)	emp_name dealer_id sales	String String String

GroupBy_1 :
Group By GroupBy_1 groups the output of 'Transformator_1'

Grouped Field(s) :

dealer_id

Sorted Field(s) :

sales Ascending

Buffer_2 :
Buffer Buffer_2 processes the output of 'GroupBy_1'

Using buffer operation pocesss :

NTile

With paramter :

Input Field	Buffer Operation	Output Field	Type
emp_name dealer_id sales	NTile(3)	emp_name dealer_id sales emp_name_new dealer_id_new sales_new BUCKET	String Integer Double String Integer Double Integer

Transformator_2 :
Transformator Transformator_2 transforms the output of 'Buffer_2' using the following transfromation function(s)

Input Field	Operation	Output Field	Type
emp_name_new	No Operation	emp_name_new	String
dealer_id_new	No Operation	dealer_id_new	Integer
sales_new	No Operation	sales_new	Double
BUCKET	No Operation	VALUE	String

Hfs_sink_1 :
HFS Sink Hfs_sink_1 writes HDFS the output of 'Transformator_2' with properties :

Fields Name	:	emp_name_new,dealer_id_new,sales_new,VALUE
Output Path	:	Arg[1]
Output Name	:	hgrid247-#####
Sink Mode	:	SinkMode.REPLACE
Partition Field(s)	:
Splitter	:
Index	: