# Select API Quickstart Guide [](https://slack.minio.io)
Traditional retrieval of objects is always as whole entities, i.e GetObject for a 5 GiB object, will always return 5 GiB of data. S3 Select API allows us to retrieve a subset of data by using simple SQL expressions. By using Select API to retrieve only the data needed by the application, drastic performance improvements can be achieved.
> This implementation is compatible with AWS S3 Select API
- Install Minio Server from [here](http://docs.minio.io/docs/minio-quickstart-guide).
- Familiarity with AWS S3 API
- Familiarity with Python and installing dependencies.
## 2. Install boto3
Install `aws-sdk-python` from AWS SDK for Python official docs [here](https://aws.amazon.com/sdk-for-python/)
## 3. Example
As an example, let us take a gzip compressed CSV file. Without S3 Select, we would need to download, decompress and process the entire CSV to get the data you needed. With Select API, can use a simple SQL expression to return only the data from the CSV you’re interested in, instead of retrieving the entire object. Following Python example shows how to retrieve the first column `Location` from an object containing data in CSV format.
Please replace ``endpoint_url``,``aws_access_key_id``, ``aws_secret_access_key``, ``Bucket`` and ``Key`` with your local setup in this ``select.py`` file.
```py
#!/usr/bin/env/env python3
import boto3
s3 = boto3.client('s3',
endpoint_url='http://localhost:9000',
aws_access_key_id='minio',
aws_secret_access_key='minio123',
region_name='us-east-1')
r = s3.select_object_content(
Bucket='mycsvbucket',
Key='sampledata/TotalPopulation.csv.gz',
ExpressionType='SQL',
Expression="select * from s3object s where s.Location like '%United States%'",
InputSerialization={
'CSV': {
"FileHeaderInfo": "USE",
},
'CompressionType': 'GZIP',
},
OutputSerialization={'CSV': {}},
)
for event in r['Payload']:
if 'Records' in event:
records = event['Records']['Payload'].decode('utf-8')
print(records)
elif 'Stats' in event:
statsDetails = event['Stats']['Details']
print("Stats details bytesScanned: ")
print(statsDetails['BytesScanned'])
print("Stats details bytesProcessed: ")
print(statsDetails['BytesProcessed'])
```
## 4. Run the Program
Upload first a sample dataset downloaded from [TotalPopulation.csv](https://esa.un.org/unpd/wpp/DVD/Files/1_Indicators%20(Standard)/CSV_FILES/WPP2017_TotalPopulationBySex.csv) using the following commands.
