How is Azure Storage Tables implemented? - azure

I'm the type of developer that likes to understand the whole stack and viewing Azure Storage Tables as a black box makes me uncomfortable.
RDBMS is an entire field of study in Computer Science. The components necessary to support ACID operations, query optimizations down to the details of B-trees to create indexes is essentially a well documented, solved problem.
Apache HBase and MongoDB are open source and Google has published multiple papers on BigTable, but I can't find anything on Microsoft's Azure Storage Tables, other than usage / developer documentation. Has Microsoft published any details on the actual implementation (algorithms, data structures and infrastructure) behind Azure Storage Tables?

The Azure Storage team presented a paper at SOSP11 describing the inner workings of the Azure Storage Service (including the Table Services).

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Can we use Microsoft Purview and Unity Catalog together

Unity Catalog is the Azure Databricks data governance solution for the Lakehouse. Whereas, Microsoft Purview provides a unified data governance solution to help manage and govern your on-premises, multicloud, and software as a service (SaaS) data.
Question: In our same Azure Cloud project, can we use Unity Catalog for the Azure Databricks Lakehouse, and use Microsoft Purview for the rest of our Azure project?
Update: In our current Azure subscription, we have divided workload as follows:
SQL related workload: we are doing all our SQL database work using Databricks only (no Azure SQL databases are involved). That is, we are using Databricks Lakehouse, Delta Lake, Deatricks SQL etc. to perform ETL and all Data Analytics work.
All Non-SQL workload: All other assets (Excel files, csv files, pdf, media files etc.) are stored in various Azure storage accounts.
MS Purview is doing a good job in scanning assets in scenario 2 above, and it easily creates a holistic, up-to-date map of our data landscape with automated data discovery, sensitive data classification, and end-to-end data lineage. It also enables our data consumers to access valuable, trustworthy data management.
However, our almost 50% of the work (SQL, ETL, Data Analytics etc.) is done in Azure Databricks where we have significant challenges with Purview. We were wondering if it's possible to keep Purview and Unity Catalog separate as follows: Purview does its Data Governance work for scenario 1 only and Unity Catalog does its Data Governance work for scenario 2 only.
This recently released update may resolve our issue of making Purview work better with Azure Databricks but we have not tried it yet: Connect to and manage Azure Databricks in Microsoft Purview (Preview)
As of right now there is no official integration between Unity Catalog and Purview yet, but it may come in the future. You may join Azure Databricks roadmap webinar that will be tomorrow to get more information.
Regarding the actual question - imho, nothing prevents you from using UC & Purview in the same Azure project.
P.S. You can get metadata & lineage information into Purview by loading data from information schema tables and using Purview APIs to store it in Purview.

Azure Data Explorer (ADX) vs Polybase vs Databricks

Question
Today I discovered another Azure service called Azure Data Explorer (ADX). Sorry for such comparison of services, I have good understanding of all except ADX. I feel like there is a big functionality overlay, so want to know the exact role of ADX in Azure infrastructure.
What is the use case when ADX is significantly better than Synapse/Databricks?
My understanding of ADX
AFAIK, ADX is a cluster (with per hour billing, like Databricks or Synapse, not like ADLA) that is handling database for you and is optimized for streaming ingestion and ad-hoc queries at scale. It also supports external tables, that has worse performance but cheaper (you pay for Blob/ADLS storage).
Details
I don't understand why do we need ADX if:
Azure Synapse has similar pricing model (cluster, per-hour), also it supports streaming ingestion and ad-hoc querying at scale. Azure Synapse support querying BlobStorage/ADLS through Polybase external tables.
Databricks is another service that is capable of doing it. Using Databricks Ingest and Delta Lake - you can ingest streaming data and consume them in both: streaming and batching way. Actually you can have interactive cluster that will handle ad-hoc queries for you.
Also if you want a real-time analytics - use Azure Stream Analytics. If you want Athena-like experience - use ADLA (still it doesn't support ADLS gen2).
Azure Data Explorer is focused on high velocity, high volume high variance (the 3 Vs of big data). It provides super fast interactive queries over such data that is streaming in. It supports json and text natively, including full text search and indexing.
It is used in a broad set of scenarios associated with sensing activity and time series in a large set of verticals: IoT, API logs, transaction monitoring and ad hoc data exploration.
Microsoft is offering ADX as a service as it is the major service that Microsoft is using for its own telemetry and all the analytical solutions as a service that we offer in Security, operational monitoring, game analytics, product insights usage analytics, Iot, Connected vehicles is built on ADX. You can find a full list in our docs. For clarity, SQL, Synapse, CosmosDB is storing its telemetry in Azure Data explorer...
SQL DW (AKA Synapse SQL pool) is an excellent data warehouse and implements the modern data warehouse pattern. ETL->Curated data model-> Load and serve via analysis services or power BI.
ADX is for real time analytics, enabling applying schema on read (SOR) on data as fresh as seconds old.
Consider ADX as a fully managed platform when replacing SOLR/Lucine based variants used for logs, time series databases and more.
Try it out in large workloads and you will see it is dramatically cheaper than the alternatives and much more powerful and performant.
Reach out to me if you need help.
Azure Data Explorer alias Kusto is focused on high volume data ingestion and almost real-time query and analytics. It is invented at Microsoft for log and telemetry analytics, but can be used for other purposes e.g. Iot, sensor data or web analytics. Same technology is used in Azure internal services like Azure Monitor and Log Analytics.
Similar capabilities could be build on Synapse or Databricks or HDInsight, but I see these as tools that fit much more broad use-cases. ADX has quite narrow focus. ADX does support queries (”KQL”) but has very limited SQL support. It is good for append only data, not for updates. It is not a data warehouse, database or data lake.
Microsoft material refers to the technology behind ADX with name Kusto. More info on this at https://learn.microsoft.com/en-us/azure/data-explorer/kusto/concepts/. A good comparison of services can be found in this blog post: https://vincentlauzon.com/2020/02/19/azure-data-explorer-kusto

Google Analytics data in Azure

Has anybody ever moved Google Analytics data into Azure? I have seen a handful of ways to do it but I am not sure what I am getting myself into. The Google Analytics data is becoming quite large and I am wondering if it is best suited to leave it in google storage and access it from Azure or move it to something like HDInsight or Data Lake. I need to join the data across several disparate data stores, SQL Azure, Blob, and Table Storage. I was also looking into Apache Drill and Presto as a possible solution to unify the data access. Just looking to see if anybody out there has dealt with this same issue and has any experience to share. Thanks!
Preface
I don't have experience with Presto so I can only comment on the feasibility of doing this with Drill. Also I have not used Azure services so my advice is theoretical.
Drill Storage Plugins
Drill will allow you to perform any SQL queries you want on data originating from different sources, provided that each data source has a storage plugin. A storage plugin is simply a piece of code in Drill that allows you to interface with a data source. Since you are concerned with performing queries on 3 data sources, we need to determine if each of those 3 data sources have a Storage plugin.
SQL Azure
I assume SQL Azure has a jdbc driver for java. If so then Drill can be configured to use SQL Azure by following these instructions.
Azure Blob
Azure Blob storage has an implementation of the hadoop filesystem api which Drill uses to read data from file systems. So you could theoretically add the hadoop-azure jar and its dependencies https://mvnrepository.com/artifact/org.apache.hadoop/hadoop-azure/2.7.0 to Drill's class path and configure Drill's DFS storage plugin to use it.
Additionally the data in Azure Blob would have to be stored in a supported file format like: json, parquet, csv, or hadoop sequence files.
Azure Table
This looks like Microsoft's custom NoSQL database. Currently Drill does not support it.
Conclusion
With a bit of work you could use Drill to query data on both Azure SQL and Blob, but not Azure Table.

On-premises replacement for Azure Tables?

Azure Tables is a great no-sql for in-cloud deployments but we also have some deployments that will be off the public internet. What's the "standalone" counterpart to Azure Tables from a programming model/API/performance perspective?
There is no on-prem offering for Windows Azure Storage today, here are the features with Windows Azure Pack.
As far as I know there is no direct equivalent of Azure Tables for an on-premises environment. Essentially Azure Table Storage is Key-Value Pair based noSql store with Strong Consistency programming model. You could look into other key value pair based noSql storage alternatives (http://en.wikipedia.org/wiki/NoSQL#Key.E2.80.93value_stores) but I guess you would need to abstract out some functionality if you're looking at just one codebase to target both kinds of stores.

Azure Tables or SQL Azure?

I am at the planning stage of a web application that will be hosted in Azure with ASP.NET for the web site and Silverlight within the site for a rich user experience. Should I use Azure Tables or SQL Azure for storing my application data?
Azure Table Storage appears to be less expensive than SQL Azure. It is also more highly scalable than SQL Azure.
SQL Azure is easier to work with if you've been doing a lot of relational database work. If you were porting an application that was already using a SQL database, then moving it to SQL Azure would be the obvious choice, but that's the only situation where I would recommend it.
The main limitation on Azure Tables is the lack of secondary indexes. This was announced at PDC '09 and is currently listed as coming soon, but there hasn't been any time-frame announcement. (See http://windowsazure.uservoice.com/forums/34192-windows-azure-feature-voting/suggestions/396314-support-secondary-indexes?ref=title)
I've seen the proposed use of a hybrid system where you use table and blob storage for the bulk of your data, but use SQL Azure for indexes, searching and filtering. However, I haven't had a chance to try that solution yet myself.
Once the secondary indexes are added to table storage, it will essentially be a cloud based NoSQL system and will be much more useful than it is now.
Despite similar names SQL Azure Tables and Table Storage have very little in common.
Here are a two links that might help you:
Table Storage, a 100x cost factor
Fat Entities on Table Storage
Basically, the first question should wonder about is Does my app really need to scale? If not, then go for SQL Azure.
For those trying to decide between the two options, be sure to factor reporting requirements into the equation. SQL Azure Reporting and other reporting products support SQL Azure out of the box. If you need to generate complex or flexible reports, you'll probably want to avoid Table Storage.
Azure tables are cheaper, simpler and scale better than SQL Azure. SQL Azure is a managed SQL environment, multi-tenant in nature, so you should analyze if your performance requirements are fit for SQL Azure. A premium version of SQL Azure has been announced and is in preview as of this writing (see HERE).
I think the decisive factors to decide between SQL Azure and Azure tables are the following:
Do you need to do complex joins and use secondary indexes? If yes, SQL Azure is the best option.
Do you need stored procedures? If yes, SQL Azure.
Do you need auto-scaling capabilities? Azure tables is the best option.
Rows within an Azure table cannot exceed 4MB in size. If you need to store large data within a row, it is better to store it in blob storage and reference the blob's URI in the table row.
Do you need to store massive amounts of semi-structured data? If yes, Azure tables are advantageous.
Although Azure tables are tremendously beneficial in terms of simplicity and cost, there are some limitations that need to be taken into account. Please see HERE for some initial guidance.
One other consideration is latency. There used to be a site that Microsoft ran with microbenchmarks on throughput and latency of various object sizes with table store and SQL Azure. Since that site's no longer available, I'll just give you a rough approximation from what I recall. Table store tends to have much higher throughput than SQL Azure. SQL Azure tends to have lower latency (by as much as 1/5th).
It's already been mentioned that table store is easy to scale. However, SQL Azure can scale as well with Federations. Note that Federations (effectively sharding) adds a lot of complexity to your application. I'm also not sure how much Federations affects performance, but I imagine there's some overhead.
If business continuity is a priority, consider that with Azure Storage you get cheap geo-replication by default. With SQL Azure, you can accomplish something similar but with more effort with SQL Data Sync. Note that SQL Data Sync also incurs performance overhead since it requires triggers on all of your tables to watch for data changes.
I realize this is an old question, but still a very valid one, so I'm adding my reply to it.
CoderDennis and others have pointed out some of the facts - Azure Tables is cheaper, and Azure Tables can be much larger, more efficient etc. If you are 100% sure you will stick with Azure, go with Tables.
However this assumes you have already decided on Azure. By using Azure Tables, you are locking yourself into the Azure platform. It means writing code very specific to Azure Tables that is not just going to port over to Amazon, you will have to rewrite those areas of your code. On the other hand programming for a SQL database with LINQ will port over much more easily to another cloud service.
This may not be an issue if you've already decided on your cloud platform.
I suggest looking at Azure Cache in combination with Azure Table. Table alone has 200-300ms latencies, with occasional spikes higher, which can significantly slow down response times / UI interactivity. Cache + Table seems to be a winning combination, for me.
For your question, I want to talk about how to decide with logic choose SQL Table and which need to use Azure Table.
As we know SQL Table is a relational database engine. but if you have a big data in one table the SQL Table is not applicable, because SQL query get big data is slow.
At this time you can choose Azure Table, the Azure Table query is so fast then SQL Table for big data, for example, in our website, someone subscribed many articles, we make the article as feed to user, every user have a copy of article title and description, so in the article table there are lots of data, if we use SQL Table, each query execution maybe take more than 30 seconds. But in Azure Table get users article feed by PartitionKey and RowKey is so fast.
From this example you may know how to choose between in SQL Table and Azure Table.
I wonder whether we are going to end up with some "vendor independent" cloud api libraries in due course?
I think that you have first to define what your application usage funnels are. Will your data model be subjected to frequent changes or it is a stable one? You have to be able to perform ultra fast inserts and reads are not so complicated? Do you need advance google like search? Storing BLOBS?
Those are the questions (and not only) that you have to ask and answer yourself in order to decide if you are more likely going to use NoSql or SQL approach in storing your data.
Please consider that both approaches can easily coexist and can be extended with BLOB storage as well.
Both Azure Tables and SQL Azure are two different beasts.Both are meant for different scenarios, one con to azure table is that you cannot move from azure to any other platform, unless you write providers in your code that can handle such shifts.

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