mirror of https://github.com/minio/minio.git
90 lines
3.9 KiB
Markdown
90 lines
3.9 KiB
Markdown
|
# 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
|
|||
|
|
|
|||
|
|
## 1. Prerequisites
|
|||
|
|
- 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.
|
|||
|
|
```sh
|
|||
|
|
$ curl "https://esa.un.org/unpd/wpp/DVD/Files/1_Indicators%20(Standard)/CSV_FILES/WPP2017_TotalPopulationBySex.csv" > TotalPopulation.csv
|
|||
|
|
$ mc mb myminio/mycsvbucket
|
|||
|
|
$ gzip TotalPopulation.csv
|
|||
|
|
$ mc cp TotalPopulation.csv.gz myminio/mycsvbucket/sampledata/
|
|||
|
|
```
|
|||
|
|
|
|||
|
|
Now let us proceed to run our select example to query for `Location` which matches `United States`.
|
|||
|
|
```sh
|
|||
|
|
$ python3 select.py
|
|||
|
|
840,United States of America,2,Medium,1950,1950.5,79233.218,79571.179,158804.395
|
|||
|
|
|
|||
|
|
840,United States of America,2,Medium,1951,1951.5,80178.933,80726.116,160905.035
|
|||
|
|
|
|||
|
|
840,United States of America,2,Medium,1952,1952.5,81305.206,82019.632,163324.851
|
|||
|
|
|
|||
|
|
840,United States of America,2,Medium,1953,1953.5,82565.875,83422.307,165988.190
|
|||
|
|
....
|
|||
|
|
....
|
|||
|
|
....
|
|||
|
|
|
|||
|
|
Stats details bytesScanned:
|
|||
|
|
6758866
|
|||
|
|
Stats details bytesProcessed:
|
|||
|
|
25786743
|
|||
|
|
```
|
|||
|
|
|
|||
|
|
## 5. Explore Further
|
|||
|
|
- [Use `mc` with Minio Server](https://docs.minio.io/docs/minio-client-quickstart-guide)
|
|||
|
|
- [Use `minio-go` SDK with Minio Server](https://docs.minio.io/docs/golang-client-quickstart-guide)
|
|||
|
|
- [Use `aws-cli` with Minio Server](https://docs.minio.io/docs/aws-cli-with-minio)
|
|||
|
|
- [Use `s3cmd` with Minio Server](https://docs.minio.io/docs/s3cmd-with-minio)
|
|||
|
|
- [The Minio documentation website](https://docs.minio.io)
|