I have started researching into Redshift. It is defined as a "Database" service in AWS. From what I have learnt so far, we can create tables and ingest data from S3 or from external sources like Hive into Redhshift database (cluster). Also, we can use JDBC connection to query these tables.
My questions are -
Is there a place within Redshift cluster where we can store our queries run it periodically (like Daily)?
Can we store our query in a S3 location and use that to create output to another S3 location?
Can we load a DB2 table unload file with a mixture of binary and string fields to Redshift directly, or do we need a intermediate process to make the data into something like a CSV?
I have done some Googling about this. If you have link to resources, that will be very helpful. Thank you.
I used cursor method using psycopg2 function in python. The sample code is given below. You have to set all the redshift credentials in env_vars files.
you can set your queries using cursor.execute. here I mension one update query so you can set your query in this place (you can set multiple queries). After that you have to set this python file into crontab or any other autorun application for running your queries periodically.
import psycopg2
import sys
import env_vars
conn_string = "dbname=%s port=%s user=%s password=%s host=%s " %(env_vars.RedshiftVariables.REDSHIFT_DW ,env_vars.RedshiftVariables.REDSHIFT_PORT ,env_vars.RedshiftVariables.REDSHIFT_USERNAME ,env_vars.RedshiftVariables.REDSHIFT_PASSWORD,env_vars.RedshiftVariables.REDSHIFT_HOST)
conn = psycopg2.connect(conn_string);
cursor = conn.cursor();
cursor.execute("""UPDATE database.demo_table SET Device_id = '123' where Device = 'IPHONE' or Device = 'Apple'; """);
conn.commit();
conn.close();
Related
My original data is from Bigquery. I have created a dag job to extract the relevant fields data based on a "WHERE" condition into a csv file stored in Google Cloud Storage
As a next step, I am aiming to use "LOAD CSV WITH EHADERS FROM gs://link-to-bucket/file.csv to read the data from the CSV to Neo4j database
It seems however that I cannot just give the the gcs uri as the CSV link. Is there anyway to establish a secure connection to read the file, other then making the the bucket public?
My attempt
uri = "gs://link-to-bucket/file.csv"
def create_LP_query(uri):
query_string = f"""
LOAD CSV WITH HEADERS FROM '{uri}' AS row
MERGE (l:Limited_Partner:Company {{id: row.id}})
SET l.Name = row.Name """
It is not possible, you would have to create a Neo4j plugin that acts as a new ProtocolHandler.
I did one in the past for S3, you might take it as inspiration, it can be similar for GS.
https://github.com/ikwattro/neo4j-load-csv-s3-protocol
Have ~50k compressed (gzip) json files daily that need to be uploaded to BQ with some transformation, no API calls. The size of the files may be up to 1Gb.
What is the most cost-efficient way to do it?
Will appreciate any help.
Most efficient way to use Cloud Data Fusion.
I would suggest below approach
Create cloud function and trigger on every new file upload to uncompress file.
Create datafusion job with GCS file as source and bigquery as sink with desired transformation.
Refer below my youtube video.
https://youtu.be/89of33RcaRw
Here is (for example) one way - https://cloud.google.com/bigquery/docs/loading-data-cloud-storage-json...
... but quickly looking over it however one can see that there are some specific limitations. So perhaps simplicity, customization and maintainability of solution can also be added to your “cost” function.
Not knowing some details (for example read "Limitations" section under my link above, what stack you have/willing/able to use, files names or if your files have nested fields etc etc etc ) my first thought is cloud function service ( https://cloud.google.com/functions/pricing ) that is "listening" (event type = Finalize/Create) to your cloud (storage) bucket where your files land (if you go this route put your storage and function in the same zone [if possible], which will make it cheaper).
If you can code Python here is some started code:
main.py
import pandas as pd
from pandas.io import gbq
from io import BytesIO, StringIO
import numpy as np
from google.cloud import storage, bigquery
import io
def process(event, context):
file = event
# check if its your file can also check for patterns in name
if file['name'] == 'YOUR_FILENAME':
try:
working_file = file['name']
storage_client = storage.Client()
bucket = storage_client.get_bucket('your_bucket_here')
blob = bucket.blob(working_file)
#https://stackoverflow.com/questions/49541026/how-do-i-unzip-a-zip-file-in-google-cloud-storage
zipbytes = io.BytesIO(blob.download_as_string())
#print for logging
print(f"file downloaded, {working_file}")
#read_file_as_df --- check out docs here = https://pandas.pydata.org/docs/reference/api/pandas.read_json.html
# if nested might need to go text --> to dictionary and then do some preprocessing
df = pd.read_json(zipbytes, compression='gzip', low_memory= False)
#write processed to big query
df.to_gbq(destination_table ='your_dataset.your_table',
project_id ='your_project_id',
if_exists = 'append')
print(f"table bq created, {working_file}")
# if you want to delete processed file from your storage to save on storage costs uncomment 2 lines below
# blob.delete()
#print(f"blob delete, {working_file}")
except Exception as e:
print(f"exception occured {e}, {working_file}")
requirements.txt
# Function dependencies, for example:
# package>=version
google-cloud-storage
google-cloud-bigquery
pandas
pandas.io
pandas-gbq
PS
Some alternatives include
Starting up a VM and run your script on a schedule and shutting VM down once process is done ( for example cloud scheduler –-> pub/sub –-> cloud function –-> which starts up your vm --> which then runs your script)
Using app engine to run your script (similar)
Using cloud run to run your script (similar)
Using composer/airflow (not similar to 1,2&3) [ could use all types of approaches including data transfers etc, just not sure what stack you are trying to use or what you already have running ]
Scheduling vertex ai workbook (not similar to 1,2&3, basically write up a jupyter notebook and schedule it to run in vertex ai)
Try to query files directly (https://cloud.google.com/bigquery/external-data-cloud-storage#bq_1) and schedule that query (https://cloud.google.com/bigquery/docs/scheduling-queries) to run (but again not sure about your overall pipeline)
Setup for all (except #5 & #6) just in technical debt to me is not worth it if you can get away with functions
Best of luck,
I have successfully scheduled my query in BigQuery, and the result is saved as a table in my dataset. I see a lot of information about scheduling data transfer in to BigQuery or Cloud Storage, but I haven't found anything regarding scheduling an export from a BigQuery table to Cloud Storage yet.
Is it possible to schedule an export of a BigQuery table to Cloud Storage so that I can further schedule having it SFTP-ed to me via Google BigQuery Data Transfer Services?
There isn't a managed service for scheduling BigQuery table exports, but one viable approach is to use Cloud Functions in conjunction with Cloud Scheduler.
The Cloud Function would contain the necessary code to export to Cloud Storage from the BigQuery table. There are multiple programming languages to choose from for that, such as Python, Node.JS, and Go.
Cloud Scheduler would send an HTTP call periodically in a cron format to the Cloud Function which would in turn, get triggered and run the export programmatically.
As an example and more specifically, you can follow these steps:
Create a Cloud Function using Python with an HTTP trigger. To interact with BigQuery from within the code you need to use the BigQuery client library. Import it with from google.cloud import bigquery. Then, you can use the following code in main.py to create an export job from BigQuery to Cloud Storage:
# Imports the BigQuery client library
from google.cloud import bigquery
def hello_world(request):
# Replace these values according to your project
project_name = "YOUR_PROJECT_ID"
bucket_name = "YOUR_BUCKET"
dataset_name = "YOUR_DATASET"
table_name = "YOUR_TABLE"
destination_uri = "gs://{}/{}".format(bucket_name, "bq_export.csv.gz")
bq_client = bigquery.Client(project=project_name)
dataset = bq_client.dataset(dataset_name, project=project_name)
table_to_export = dataset.table(table_name)
job_config = bigquery.job.ExtractJobConfig()
job_config.compression = bigquery.Compression.GZIP
extract_job = bq_client.extract_table(
table_to_export,
destination_uri,
# Location must match that of the source table.
location="US",
job_config=job_config,
)
return "Job with ID {} started exporting data from {}.{} to {}".format(extract_job.job_id, dataset_name, table_name, destination_uri)
Specify the client library dependency in the requirements.txt file
by adding this line:
google-cloud-bigquery
Create a Cloud Scheduler job. Set the Frequency you wish for
the job to be executed with. For instance, setting it to 0 1 * * 0
would run the job once a week at 1 AM every Sunday morning. The
crontab tool is pretty useful when it comes to experimenting
with cron scheduling.
Choose HTTP as the Target, set the URL as the Cloud
Function's URL (it can be found by selecting the Cloud Function and
navigating to the Trigger tab), and as HTTP method choose GET.
Once created, and by pressing the RUN NOW button, you can test how the export
behaves. However, before doing so, make sure the default App Engine service account has at least the Cloud IAM roles/storage.objectCreator role, or otherwise the operation might fail with a permission error. The default App Engine service account has a form of YOUR_PROJECT_ID#appspot.gserviceaccount.com.
If you wish to execute exports on different tables,
datasets and buckets for each execution, but essentially employing the same Cloud Function, you can use the HTTP POST method
instead, and configure a Body containing said parameters as data, which
would be passed on to the Cloud Function - although, that would imply doing
some small changes in its code.
Lastly, when the job is created, you can use the Cloud Function's returned job ID and the bq CLI to view the status of the export job with bq show -j <job_id>.
Not sure if this was in GA when this question was asked, but at least now there is an option to run an export to Cloud Storage via a regular SQL query. See the SQL tab in Exporting table data.
Example:
EXPORT DATA
OPTIONS (
uri = 'gs://bucket/folder/*.csv',
format = 'CSV',
overwrite = true,
header = true,
field_delimiter = ';')
AS (
SELECT field1, field2
FROM mydataset.table1
ORDER BY field1
);
This could as well be trivially setup via a Scheduled Query if you need a periodic export. And, of course, you need to make sure the user or service account running this has permissions to read the source datasets and tables and to write to the destination bucket.
Hopefully this is useful for other peeps visiting this question if not for OP :)
You have an alternative to the second part of the Maxim answer. The code for extracting the table and store it into Cloud Storage should work.
But, when you schedule a query, you can also define a PubSub topic where the BigQuery scheduler will post a message when the job is over. Thereby, the scheduler set up, as described by Maxim is optional and you can simply plug the function to the PubSub notification.
Before performing the extraction, don't forget to check the error status of the pubsub notification. You have also a lot of information about the scheduled query; useful is you want to perform more checks or if you want to generalize the function.
So, another point about the SFTP transfert. I open sourced a projet for querying BigQuery, build a CSV file and transfert this file to FTP server (sFTP and FTPs aren't supported, because my previous company only used FTP protocol!). If your file is smaller than 1.5Gb, I can update my project for adding the SFTP support is you want to use this. Let me know
I need to automate a process to extract data from Google Big Query and exported to an external CSV in a external server outside of the GCP.
I just researching how to to that I found some commands to run from my External Server. But I prefer to do everything in GCP to avoid possible problems.
To run the query to CSV in Google storage
bq --location=US extract --compression GZIP 'dataset.table' gs://example-bucket/myfile.csv
To Download the csv from Google Storage
gsutil cp gs://[BUCKET_NAME]/[OBJECT_NAME] [OBJECT_DESTINATION]
But I would like to hear your suggestions
If you want to fully automatize this process, I would do the following:
Create a Cloud Function to handle the export:
This is the more lightweight solution, as Cloud Functions are serverless, and provide flexibility to implement code with the Client Libraries. See the quickstart, I recommend you to use the console to create the functions to start with.
In this example I recommend you to trigger the Cloud Function from an HTTP request, i.e. when the function URL is called, it will run the code inside of it.
An example Cloud Function code in Python, that creates the export when a HTTP request is made:
main.py
from google.cloud import bigquery
def hello_world(request):
project_name = "MY_PROJECT"
bucket_name = "MY_BUCKET"
dataset_name = "MY_DATASET"
table_name = "MY_TABLE"
destination_uri = "gs://{}/{}".format(bucket_name, "bq_export.csv.gz")
bq_client = bigquery.Client(project=project_name)
dataset = bq_client.dataset(dataset_name, project=project_name)
table_to_export = dataset.table(table_name)
job_config = bigquery.job.ExtractJobConfig()
job_config.compression = bigquery.Compression.GZIP
extract_job = bq_client.extract_table(
table_to_export,
destination_uri,
# Location must match that of the source table.
location="US",
job_config=job_config,
)
return "Job with ID {} started exporting data from {}.{} to {}".format(extract_job.job_id, dataset_name, table_name, destination_uri)
requirements.txt
google-cloud-bigquery
Note that the job will run asynchronously in the background, you will receive a return response with the job ID, which you can use to check the state of the export job in the Cloud Shell, by running:
bq show -j <job_id>
Create a Cloud Scheduler scheduled job:
Follow this documentation to get started. You can set the Frequency with the standard cron format, for example 0 0 * * * will run the job every day at midnight.
As a target, choose HTTP, in the URL put the Cloud Function HTTP URL (you can find it in the console, inside the Cloud Function details, under the Trigger tab), and as HTTP method choose GET.
Create it, and you can test it in the Cloud Scheduler by pressing the Run now button in the Console.
Synchronize your external server and the bucket:
Up until now you only have scheduled exports to run every 24 hours, now to synchronize the bucket contents with your local computer, you can use the gsutil rsync command. If you want to save the imports, lets say to the my_exports folder, you can run, in your external server:
gsutil rsync gs://BUCKET_WITH_EXPORTS /local-path-to/my_exports
To periodically run this command in your server, you could create a standard cron job in your crontab inside your external server, to run each day as well, just at a few hours later than the bigquery export, to ensure that the export has been made.
Extra:
I have hard-coded most of the variables in the Cloud Function to be always the same. However, you can send parameters to the function, if you do a POST request instead of a GET request, and send the parameters as data in the body.
You will have to change the Cloud Scheduler job to send a POST request to the Cloud Function HTTP URL, and in the same place you can set the body to send the parameters regarding the table, dataset and bucket, for example. This will allow you to run exports from different tables at different hours, and to different buckets.
I'm look for a manual and automatic way to use SQL Workbench to import/load a LOCAL csv file to a AWS Redshift database.
The manual way could be a way that click a navigation bar and select a option.
The automatic way could be some query codes to load the data, just run it.
here's my attempt:
there's an error "my target table in AWS is not found." but I'm sure the table exists, anyone know why?
WbImport -type=text
-file ='C:\myfile.csv'
-delimiter = ,
-table = public.data_table_in_AWS
-quoteChar=^
-continueOnError=true
-multiLine=true
You can use wbimport in SQL Workbench/J to import data
For more info : http://www.sql-workbench.net/manual/command-import.html
Like it was mentioned in the comments COPY command provided by Redshift is the optimal solution. You can use copy from S3, EC2 etc.
S3 Example:
copy <your_table>
from 's3://<bucket>/<file>'
access_key_id 'XXXX'
secret_access_key 'XXXX'
region '<your_region>'
delimiter '\t';
For more examples:
https://docs.aws.amazon.com/redshift/latest/dg/r_COPY_command_examples.html