CosmosDB: Unable to run group by query in python SDK - python

I am trying to run a group by query in Azure CosmosDB using Python SDK.
I've set enable_cross_partition_query=True in the container client settings
{"errors":["Cross partition query only supports 'VALUE <AggregateFunc>' for aggregates"]}
I have multiple aggregates in my query. Below is my sample query
select count(col1) as alias1, sum(col2) as alias2......from container group by col1
Nothing is working.... Please help if there are any alternatives to do this

Python SDK for Azure Cosmos DB does not have the support for GROUP BY operations,
You can read it here under the limitations.

Related

Accessing an Azure Database for MySQL Single Server from outside Azure

Moving this question from DevOps Stack Exchange where it got only 5 views in 2 days:
I would like to query an Azure Database for MySQL Single Server.
I normally interact with this database using a universal database tool (dBeaver) installed onto an Azure VM. Now I would like to interact with this database using Python from outside Azure. Ultimately I would like to write an API (FastAPI) allowing multiple users to connect to the database.
I ran a simple test from a Jupyter notebook, using SQLAlchemy as my ORM and specifying the pem certificate as a connection argument:
import pandas as pd
from sqlalchemy import create_engine
cnx = create_engine('mysql://XXX', connect_args={"ssl": {"ssl_ca": "mycertificate.pem"}})
I then tried reading data from a specific table (e.g. mytable):
df = pd.read_sql('SELECT * FROM mytable', cnx)
Alas I ran into the following error:
'Client with IP address 'XX.XX.XXX.XXX' is not allowed to connect to
this MySQL server'.
According to my colleagues, a way to fix this issue would be to whitelist my IP address.
While this may be an option for a couple of users with static IP addresses I am not sure whether it is a valid solution in the long run.
Is there a better way to access an Azure Database for MySQL Single Server from outside Azure?
As mentioned in comments, you need to whitelist the IP address ranges(s) in the Azure portal for your MySQL database resource. This is a well accepted and secure approach.

Snowflake - compare 2 tables and send notification for mismatches

I am looking for setting up a alert notification either from snowflake or aws side or by glue jobs / lambda functions using python or scala.
I would like to compare 2 tables which holds table names and counts in source and target.
data is loaded from s3 to snowflake via aws glue job and after that I would like to compare the 2 tables to verify if source and target record counts are matching and for any mismatches send a notification.
Please let me know your inputs to achieve this task.
Thanks,
Jo
If you are using AWS Glue to load the tables in Snowflake, you can continue using Glue to orchestrate the desired result:
Have Glue load the table.
Have Glue run a stored procedure in Snowflake comparing both tables.
https://snowflakecommunity.force.com/s/article/How-to-Use-AWS-Glue-to-Call-Procedures-in-Snowflake
Have AWS Glue send a notification through SNS.
https://aws.amazon.com/blogs/big-data/build-and-automate-a-serverless-data-lake-using-an-aws-glue-trigger-for-the-data-catalog-and-etl-jobs/
See the chapter "Monitoring and notification with Amazon CloudWatch Events".
If you need SQL for the stored procedure that compares two tables, please feel free to add a new question.

Connectiong to Azure table storage from Azure databricks

I am trying to connecto to azure table storage from Databricks. I can't seem to find any resources that doesn't go to blob containers, but I have tried modifying it for tables.
spark.conf.set(
"fs.azure.account.key.accountname.table.core.windows.net",
"accountkey")
blobDirectPath = "wasbs://accountname.table.core.windows.net/TableName"
df = spark.read.parquet(blobDirectPath)
I am making an assumption for now that tables are parquet files. I am getting authentication errors on this code now.
According to my research, Azure Databricks does not support the data source of Azure table storage. For more details, please refer to https://docs.azuredatabricks.net/spark/latest/data-sources/index.html.
Besides if you still want to use table storage, you can use Azure Cosmos DB Table API. But they have some differences. For more details, please refer to https://learn.microsoft.com/en-us/azure/cosmos-db/faq#where-is-table-api-not-identical-with-azure-table-storage-behavior.

AWS Redshift Data Processing

I'm working with a small company currently that stores all of their app data in an AWS Redshift cluster. I have been tasked with doing some data processing and machine learning on the data in that Redshift cluster.
The first task I need to do requires some basic transforming of existing data in that cluster into some new tables based on some fairly simple SQL logic. In an MSSQL environment, I would simply put all the logic into a parameterized stored procedure and schedule it via SQL Server Agent Jobs. However, sprocs don't appear to be a thing in Redshift. How would I go about creating a SQL job and scheduling it to run nightly (for example) in an AWS environment?
The other task I have involves developing a machine learning model (in Python) and scoring records in that Redshift database. What's the best way to host my python logic and do the data processing if the plan is to pull data from that Redshift cluster, score it, and then insert it into a new table on the same cluster? It seems like I could spin up an EC2 instance, host my python scripts on there, do the processing on there as well, and schedule the scripts to run via cron?
I see tons of AWS (and non-AWS) products that look like they might be relevant (AWS Glue/Data Pipeline/EMR), but there's so many that I'm a little overwhelmed. Thanks in advance for the assistance!
ETL
Amazon Redshift does not support stored procedures. Also, I should point out that stored procedures are generally a bad thing because you are putting logic into a storage layer, which makes it very hard to migrate to other solutions in the future. (I know of many Oracle customers who have locked themselves into never being able to change technologies!)
You should run your ETL logic external to Redshift, simply using Redshift as a database. This could be as simple as running a script that uses psql to call Redshift, such as:
`psql <authentication stuff> -c 'insert into z select a, b, from x'`
(Use psql v8, upon which Redshift was based.)
Alternatively, you could use more sophisticated ETL tools such as AWS Glue (not currently in every Region) or 3rd-party tools such as Bryte.
Machine Learning
Yes, you could run code on an EC2 instance. If it is small, you could use AWS Lambda (maximum 5 minutes run-time). Many ML users like using Spark on Amazon EMR. It depends upon the technology stack you require.
Amazon CloudWatch Events can schedule Lambda functions, which could then launch EC2 instances that could do your processing and then self-Terminate.
Lots of options, indeed!
The 2 options for running ETL on Redshift
Create some "create table as" type SQL, which will take your source
tables as input and generate your target (transformed table)
Do the transformation outside of the database using an ETL tool. For
example EMR or Glue.
Generally, in an MPP environment such as Redshift, the best practice is to push the ETL to the powerful database (i.e. option 1).
Only consider taking the ETL outside of Redshift (option 2) where SQL is not the ideal tool for the transformation, or the transformation is likely to take a huge amount of compute resource.
There is no inbuilt scheduling or orchestration tool. Apache Airflow is a good option if you need something more full featured than cron jobs.
Basic transforming of existing data
It seems you are a python developer (as you told you are developing Python based ML model), you can do the transformation by following the steps below:
You can use boto3 (https://aws.amazon.com/sdk-for-python/) in order
to talk with Redshift from any workstation of you LAN (make sure
your IP has proper privilege)
You can write your own functions using Python that mimics stored procedures. Inside these functions, you can put / constrict your transformation
logic.
Alternatively, you can create function-using python in Redshift as well that will act like Stored Procedure. See more here
(https://aws.amazon.com/blogs/big-data/introduction-to-python-udfs-in-amazon-redshift/)
Finally, you can use windows scheduler / corn job to schedule your Python scripts with parameters like SQL Server Agent job does
Best way to host my python logic
It seems to me you are reading some data from Redshift then create test and training set and finally get some predicted result (records).If so:
Host the scrip in any of your server (LAN) and connect to Redshift using boto3. If you need to get large number of rows to be transferred over internet, then EC2 in the same region will be an option. Enable the EC2 in ad-hoc basis, complete you job and disable it. It will be cost effective. You can do it using AWS framework. I have done this using .Net framework. I assume boto3 does have this support.
If your result set are relatively smaller you can directly save them into the target redshift table
If result sets are larger save them into CSV (there are several Python libraries) and upload the rows into a staging table using copy command if you need any intermediate calculation. If not, upload them directly into the target table.
Hope this helps.

create RDS user with boto3

I'm trying to create an AWS Lambda webservice that takes a payload with a new username / password to create a new database and user in an RDS instance.
I'd like to use Boto3 to accomplish this, but I can't seem to find any documentation for this function.
Is this possible using this setup?
Currently AWS SDKs for RDS(Including Boto3 SDK) does not support this nor the AWS CLI.
Its because, creating DB users unique to each DB instance type (mysql, oracle & etc).
The option you have is to run a DDL query using your respective database driver.
http://boto3.readthedocs.io/en/latest/reference/services/rds.html#RDS.Client.generate_db_auth_token documents how create an auth token for connecting to an RDS instance and http://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/UsingWithRDS.IAMDBAuth.html covers other setup details.

Categories

Resources