Microsoft Azure Cosmos DB Reviews

We have been using Cosmos DB for everything involving non-relational data. Recently, we’ve been utilizing it more for AI purposes, especially for conversation histories.

Cosmos DB performs well with production workloads that have many gigabytes of information. You can scale it to add more capacity while providing the level of performance that customers expect.

We value the replication and regional availability features that Cosmos DB provides. The replication includes read replicas and write replicas. The recent addition of vectorization and similarity comparisons add values for AI workloads. The performance and scaling capabilities of Cosmos DB are excellent, allowing it to handle large workloads compared to other services such as Azure AI Search.

The solution is straightforward in terms of the interface, API set, and automation capabilities. The learning curve is short if you're familiar with the world of non-relational data. It takes about three to six months to learn about the distribution capabilities of Cosmos as a service. It takes a bit more time to learn the networking settings that you can use for Cosmos in South Asia, including virtual networks, private networks, finance, etc.

The vector database is interesting. We haven't used it before. We were using Azure AI search for that, but we've had great conversations with the product team, and we realize that a couple of workloads are more appropriate for Cosmos. The search results quality is still determined by Azure AI search, and we haven't used vector databases in production workloads. However, from what we've seen from a hands-on demo, it can help.

A minor improvement would be enabling batch operations through the UI. Currently, to delete all documents in a collection, we must use an API, which some of my team finds inconvenient for admin tasks.

We have been using Cosmos DB for six years.

Cosmos DB performs exceptionally well and has not caused any issues that necessitate adjustments in nodes for improved performance.

The solution scales exceptionally well. Partitioning, indexation for collections, and the dynamic scaling feature allow us to manage performance and costs effectively. We like that it can auto-scale to demand, ensuring we only pay for what we use.

Before Cosmos DB, we used Python for non-relational data. However, choosing Cosmos was straightforward due to our focus on leveraging Microsoft services.

For our migration, we had to integrate both products. The source had its own interface and APIs. In terms of syncing data, we had to incorporate it directly with Cosmos. Cosmos has excellent APIs and operation services. It was easy to orchestrate migration from one data center system to the other.

The challenges were more related to network performance than anything else. We had to build our migration very close to the Microsoft network. We were working with higher network latency by doing it inside a VM on Azure.

Our team built a migration orchestration integrating both the source and Cosmos systems using APIs.

Since starting with Cosmos DB, we have seen an overall reduction in our total ownership cost of 5 to 10 percent.

Everything could always be cheaper. I like that Cosmos DB allows us to auto-scale instead of pre-provisioning a certain capacity. It automatically scales to the demand, so we only pay for what we consume.

I rate Cosmos DB nine out of 10.

I'm the primary systems architect at DocuSign. We just launched a product at called Intelligent Agreement Management, and a central pillar of that is schema understanding. We use Microsoft Azure Cosmos DB as our schema store. It's the brains of our entire system. 

It is integral to our business because it helps manage schema and metadata for all our documents and customers. The AI insights we glean based on Azure OpenAI also end up in Cosmos DB. We need a NoSQL store because the schema is dynamic and flexible, so Cosmos DB is a great fit. It has four nines or possibly five nines availability, excellent geo-distribution, and auto-scaling. 

Cosmos DB has improved search result quality, throughput, and query latency. There are trade-offs to finding the sweet spot among all of these. Having a NoSQL solution that can do that in a 100 percent Azure shop is the best fit we could want. 

The features that stand out as most valuable are the autoscaling and hierarchical partition keys. We use account IDs at a higher level and entity IDs at a lower level. That gives us optimal query performance for our workloads.

AI has been a game-changer for new people without expertise, making it easier to use and optimize. You can ask GPT or Copilot for optimization strategies. If you have queries that are not performing well, you can feed the same queries, execution plan, and other things to the AI. The AI returns reasonable recommendations for what to do. 

Cosmos DB is effective at handling large queries. At DocuSign, we're processing over a billion signers and massive agreements and contracts. These things are being used for business-critical workloads, so performance, scale handling, and latency are crucial. Without these, we wouldn't have a product that anyone would want to use. 

I have worked with Cosmos DB at my company for the past 18 months, but I have used Cosmos at Microsoft for nearly a decade.

Cosmos DB provides impressive stability due to its high availability and ability to handle massive data volumes, which is essential for our business-critical workloads.

We have found Cosmos DB’s scalability to be exceptional, enabling horizontal and vertical sharding and supporting massive scale with efficient auto-scaling.

The team behind Cosmos DB has been highly responsive, providing excellent transparency and high-quality postmortem reviews during incidents, ensuring continuous support and improvement.

Positive

The initial setup was straightforward. Cosmos DB's integration went quickly due to the team's prior experience with Azure services, allowing us to prototype within a couple of months.

The challenge for us is always scale. We needed to move all the tables in lockstep that are involved in join queries. In some cases, we came up with a structured pipeline where stage one would go to SQL, and some of the query hints for the Cosmos DB thing would come from that first stage and so on. That was a migration challenge in normalizing the data, bringing it into Cosmos, and then, again, denormalizing some of the data. 

The critical mass of internal expertise, particularly from people previously working with Azure, enabled a smooth implementation with Cosmos DB.

Cosmos DB has always met our targets. However, we've always had our schema store on Cosmos DB, so it's not like we started with something expensive and brought our TCO down using Cosmos. Still, it's an excellent option for NoSQL or semi-structured data because our agreements start as a morass of raw data from PDF, OCR PDF, or paper OCR scans. 

After that, we match the structure with a known entity and for that known customer and run queries on Cosmos DB to bring out the rest of the structure and use AI to enhance it even further. In some cases, the customer will add custom fields to their entities. Cosmos gives us a low turnaround time from when the dynamic nature kicks into when the results return from that new schema information back to the same customer. It's a rich, complex scenario, but also a massive scale of data and customers.

The pricing model for Cosmos DB has aligned well with our budget expectations. We did not encounter pain points related to costs and found it cost-effective compared to high-end SQL solutions initially considered.

When I joined, the company was already invested in Azure, so there was never a bake-off between Cosmos DB and offerings from AWS. We implemented Cosmos initially because we have a massive transaction database on SQL. On things like the total cost of ownership, Cosmos DB shines. It seems to be the correct approach for our semi-structured data and our schema and entity store. A combination of Cosmos DB and SQL Azure was how we shaped our architecture on this journey, but we didn't evaluate Cosmos DB against non-Azure NoSQL databases.

I would rate Cosmos DB as an eight out of 10 for its overall capabilities, responsiveness, and alignment with our needs.

Our primary use case for Cosmos is the storage of shell-fed signs and our pricing systems. We use it as a transactional database on the back end.

The ability to scale automatically is very valuable. Additionally, multi-region support automatically synchronizing to a different region for multi-region applications is a cool feature. It's more of a lift with other databases to configure that extra region and set up replication, even if it's on the cloud. With Azure, it's just a button click. It's that simple. 

The learning curve depends on your background. It takes time to learn if you're from a relational database background like us. However, it's fairly straightforward from a scalability perspective once you get the hang of it. You need to be aware of certain concepts like partitions and partition keys. Once you get those, I think it's fairly okay.

The auto-scaling feature adjusts hourly. We have many processes that write stuff in batches, so we must ensure that the load is spread evenly throughout the hour. It would be much easier if it were done by the minute. I'm looking forward to the vector database search that they are adding. It's a pretty cool new feature. 

I have used Cosmos for about five years.

The latency and availability are good. I don't have any complaints there. It goes back to how you're retrieving data and whether it's structured correctly. 

Cosmos can definitely scale well, but it comes with a cost. One of our databases is quite large and scaled up significantly due to our needs.

We have two databases, so it was challenging to define the partition key and ensure the workloads are spread out. We have millions of records in our Cosmos database, so spreading that out was difficult. We had to spread out the load to avoid a 429 error for a request that was too large. Partition key is more of a learning experience to understand the right thing to do. The entire process took around six months. It wasn't too hard.

We have reduced our overhead through dynamic scaling. I can't say precisely how much we've reduced our total cost of ownership using Cosmos DB, but we have a similar on-prem workload running on SQL, and we only pay a fraction for Cosmos.

Cosmos is cheaper than other solutions, but you must be smart about how you use it to keep costs down. We've made mistakes where the cost has increased more than we expected. You have the opportunity for it to be cheap or costly.

We were looking for a multi-region document database, and the ease of configuring multi-region in Cosmos was a significant factor in our choosing the solution. We also wanted to bring costs down, which was the other reason.

I would rate Cosmos an eight out of ten. Be cautious about spreading out the load evenly, especially when dealing with large volumes to prevent getting errors.

We have many use cases. We are using Microsoft Azure Cosmos DB for our event streaming framework. We are using Microsoft Azure Cosmos DB to store all the event data for AI activities.

We are also using it for a RAG-based solution, though it is not entirely RAG-based. We are using Microsoft Azure Cosmos DB as a staging solution, and then we are using the AI search to index it and continue to the RAG for the LLM.

We are just using it as a staging solution. We have use cases for extracting huge documents, which can be more than 500 pages or even 10,000 pages. We cannot directly use the LLM, so we have to use a RAG-based approach. For that, we have chosen Microsoft Azure Cosmos DB and we are using the vectors there. However, instead of directly querying the vectors in Microsoft Azure Cosmos DB, we are indexing that in AI search.

The searching capability is exceptional. It is very simple and incomparable to competitors. With SQL, we have to install everything, but this is pretty quick. We have a Bicep template. Using the Bicep template to create Microsoft Azure Cosmos DB containers and partition keys makes everything convenient. Scaling is also convenient.

The RUs still appear to be a black box for everyone. Even though they explain read and write RUs, it remains unclear for many users. With Microsoft Azure Cosmos DB, we are using event streaming in the entire organization. We are using a framework for event streaming, and we suddenly reached a huge amount - the capacity of 20 GB partition key. When it reaches 100% of RUs, we face issues. We have to work on rebuilding the partition key. 

Regarding billing, we need better control. Sometimes it exceeds the forecasted budget. More clarity on RUs would be beneficial, even though documentation exists.

There is a 2 MB limitation for a document, which is a hard limit. Additionally, modeling in Microsoft Azure Cosmos DB is more challenging compared to RDBMS and other NoSQL solutions because we cannot store everything in one place. Since it's NoSQL, we sometimes need to split one document into multiple containers due to the 2 MB limitation.

I have been using it for more than two years.

Its stability is good. I would rate it an eight out of ten for stability.

Scalability is pretty good. I would rate it an eight out of ten for scalability.

I would give a low rating to Microsoft support, as whenever I talked to them, I never got a solution. I had to guide them.

If the support ticket lands in certain regions such as Sweden, they have more knowledge and the ticket gets resolved easily. At times, it moves between departments, requiring escalation to get the correct person involved.

The support team needs improvement in understanding who they are talking to. They should not ask basic questions when speaking with experienced users. I am deeply knowledgeable about Microsoft Azure Cosmos DB, which I have had to explain to the support team.

Neutral

It is very simple. We can't compare it with any competitor. We just use the Bicep template.

Its implementation takes a maximum of one hour.

Because of the lack of understanding about RUs, the costs become unpredictable. It sometimes goes over the budget.

Currently, they are implementing Fabric and OneLake solutions. Fabric appears faster. According to Microsoft representatives, querying in Fabric instead of Microsoft Azure Cosmos DB will be quicker. However, I remain confident in the querying capability of Microsoft Azure Cosmos DB.

It is pretty good, and currently, everyone wants to move from Microsoft Azure Cosmos DB to Databricks, but when I query data in Databricks, it takes considerable time with huge amounts of data. It stores in the BLOB in the backend, but when we use Microsoft Azure Cosmos DB, it retrieves the data much faster. The main consideration is being careful with fixing the partition key.

I would strongly recommend it for new projects. When you create a project from scratch, it is easy to implement Microsoft Azure Cosmos DB because the library is very pretty good. You can just use the library and create a container. I do not see any complexity at all in using Microsoft Azure Cosmos DB. 

I would rate Microsoft Azure Cosmos DB a nine out of ten.

For retail, all the backend data, such as merchandise items, is stored in Microsoft Azure Cosmos DB. This data is processed by backend APIs, and the UI can perform displays, printouts, edits, creations, etc.

Cost-wise, it is transparent. It supports traceability. Any activity happening in your Microsoft Azure Cosmos DB can be seen from the Azure portal via log events. If you have some sort of observability, you can centralize logging and create historical insights or virtualization based on the activity. By default, Microsoft Azure Cosmos DB provides all of that on their main portal.

It is responsive when you have a large dataset stored in your Microsoft Azure Cosmos DB. It is no problem. You can quickly scale it. Unlike traditional solutions, you do not have to deal with a separate team managing the database.

Search results have been good. It is a good experience because you can search results via the Azure portal, via a query, or via CLI. You have plenty of options. Aside from that, you can do quick scaling of your Microsoft Azure Cosmos DB whenever you have an issue with the workload, capacity, etc.

Traditional database solutions require back-and-forth coordination between teams which can lead to delays in implementing simple tasks. With Microsoft Azure Cosmos DB running on the cloud, the developer can do a quick query, and the operator can do technical analysis or troubleshooting. It is beneficial overall in terms of operational effectiveness.

Optimization is achieved through indexes. It is pretty similar to other SQL or database solutions. Microsoft Azure provides Data Studio, where you can explore your schema, tweak it, create a backup, and restore existing data within Microsoft Azure Cosmos DB. These tools make your life easier if you do not like working with the CLI.

Microsoft Azure Cosmos DB is a good solution for distributed application requirements. We can perform multi-modeling. For modern applications, I would recommend Microsoft Azure Cosmos DB. It caters to different types of applications and also provides an API base wherein you can perform automated updates for your Microsoft Azure Cosmos DB resources.

It provides all the common features that other database solutions offer. The difference is that Microsoft Azure Cosmos DB is cloud-hosted. You can host it on-prem, but running in the cloud simplifies everything in terms of support and availability.

Overall, it works very well and fits the purpose regardless of the target application. However, by default, there is a threshold to accommodate bulk or large requests. You have to monitor the Request Units. If you need more data for a particular query, you need to increase the Request Units.

I have only used the technology for three to four months.

It depends on how you configure your Microsoft Azure Cosmos DB. If you are using it as a standalone service, you are unlikely to gain the full benefits of having Microsoft Azure Cosmos DB running on the cloud. However, if you consider scale sets and scalability, for example, you can achieve higher stability.

With Microsoft Azure Cosmos DB, we created an availability zone to ensure that there is a replica of the primary Microsoft Azure Cosmos DB instance. If the primary goes down, there is a secondary database that they can use for the application. The backend application gets repointed to the secondary instance.

I do not see any problem with the latency. Connecting from your local client like Azure Data Studio to your Microsoft Azure Cosmos DB can take time, but if you are going to connect an application to the database in the same region, there is no latency at all.

It is highly scalable. I would rate it a nine out of ten for scalability.

We can quickly scale using Terraform. We can perform horizontal and vertical scaling with Terraform and apply it. It will automatically reflect in our Azure environment.

Excellent support always comes from Microsoft. If you have a problem with different services, you just raise a ticket, and someone will reach out to you. I can elevate the severity depending on the criticality of your issues and the impact.

Positive

We did not use any other solution previously because this is a new project for modernizing the merchandising area.

The setup is easy, especially in the cloud, so I would rate it a nine out of ten for the ease.

All our infrastructure layers are being controlled by Terraform. If we want to set up a new environment, it can be done within a day for not only Microsoft Azure Cosmos DB but also all resources required for an end-to-end application flow.

You can do it yourself. They have good documentation, which is easy to follow.

You can get an ROI in a year, provided you deploy it properly with the right baseline forecasted plan in terms of resource sizing. There are many factors when it comes to ROI, such as how quickly you can onboard your application and consume the backend Microsoft Azure Cosmos DB. For those new to the cloud, it might be hard to get the ROI quickly, but those with existing resources in the cloud can achieve their ROI in the short term.

It can save a lot if you perform regular monitoring. If you have a monitoring team for checking the overall utilization of Microsoft Azure Cosmos DB resources, it will save a lot of cost. You can react quickly and trim down the specs, memory, RAM, storage size, etc. It can save about 20% of the costs.

Its cost is transparent. Pricing depends on the transaction and data size, but overall, it is cheaper compared to hosting it on your corporate network due to other factors like power consumption. 

Current pricing is fine, and you can scale it afterward. You can start with a small size and scale eventually. That is a benefit of having Microsoft Azure Cosmos DB on the cloud.

It was the primary platform choice of the client at the time.

You can quickly learn Microsoft Azure Cosmos DB if you are familiar with how databases work.

Microsoft Azure Cosmos DB offers all you need for a particular database solution. It is better if you can host it in the cloud, applying security controls like data at rest and data in transit. You must ensure Microsoft Azure cloud is only accessible in a secure manner.

Scalability-wise, you can quickly scale your Microsoft Azure Cosmos DB, unlike on-premises, where you must request and procure additional resources. There is no such need; you can use infrastructure as code like Terraform and adjust the resource specs whenever you like. There are no capacity and workload concerns.

I would rate Microsoft Azure Cosmos DB a nine out of ten.

Our primary use case is a product to generate insights from several terabytes of data. The main problem was accuracy, as we couldn't get accurate insights because the data was hallucinating. After some trial and error, we found a solution with Azure Cosmos DB and MongoDB and got an acceptable cosine similarity score. We use Azure Cosmos DB collections and Azure functions to get the results we were looking for.

Cosmos DB improved our search result quality. Our response's accuracy rate is higher than 85 percent, which is amazing for such a large volume of data. We are searching several terabytes of data, and our harmonized data layer is pretty big. We get data from multiple global data providers. 

We use Databricks as well. The entire framework is built on Python. We have structured and unstructured data pipelines. There are multiple layers to our architecture, but Cosmos DB is the main one.

Our team has found the vCore index to be one of the most valuable features. We have tokenized and vectorized our entire database and stored this data in MongoDB collections with a vCore index, which works like magic for keyword selection. 

Additionally, the interface is user-friendly and seamlessly connects with other Azure offerings, making integration with other services easy. The learning curve was short. Our experts understand data well, but they had to build knowledge of the AI stack. It took a little bit of learning. However, it was easy to understand. In a couple of weeks, they could do everything.

The vector database is the core feature we use. Our data was not accurate, and we wanted to create a ChatGPT-type functionality where the user could ask a question in plain English like, "Show me the top 10 vegan companies in the US." But the vegan is not tagged as "vegan." It could be "plant-based," so you add that keyword. Then, it's not the end of it. Things are tagged as soya
milk," "oat milk," etc. 

There was no other way to solve our problem with hallucination and deal with a huge volume of structured and unstructured data. The only option is to vectorize. And we looked at several vector databases, but none came close. The vector database integrates seamlessly. When we use the cosine similarity search and retrieve the keywords. These keywords then eventually feed into our SQL query formation. After that, we use OpenAI to summarize everything. It seamlessly integrates with everything.

There aren't any specific areas that need improvement, but if there were a way to achieve the right cosine similarity score without extensive testing, that would be very beneficial.

I have been using Azure Cosmos DB for close to a year. 

Cosmos DB proves to be stable with its seamless integration, accuracy, and consistency, making it a reliable choice for our needs.

We have not extensively tested the scalability, but it appears straightforward with the Microsoft stack. Scalability has never been an issue for us.

Customer service and support have been great. We receive good cooperation not only from the Cosmos DB team but across the entire Azure stack.

Positive

Before adopting Azure Cosmos DB, we tried different vector databases, but none were working. It was suggested by a Microsoft colleague, and it has been fundamental to our architecture since.

The initial setup was seamless. During our proof of concepts (POCs), everything was within the Azure OpenAI stack. It worked for us and seamlessly integrated with the rest.

In the three months prior, our hosting run rate was approximately $550,000 per month, which has since decreased to $280,000 in October. Last year was more about building things. This year, we are trying to optimize things and getting the right support. 

The pricing aligns with our expectations, given our extensive use of the Azure stack. This year, we are focusing on optimization and cost reduction across the Azure stack.

We considered several vector databases. Being an enterprise customer with Microsoft, security and reliability were deciding factors. Open-source vector databases were also considered.

I rate Azure Cosmos DB as nine out of 10. The product is fit for purpose and performs well,

Our primary use case for Azure Cosmos DB is mainly as a Document DB and vector DB.

Azure Cosmos DB is very easy to use. We do not have to spend a lot of time on its optimization.

There is a lot of reference code we can use. It is very easy. We could grab some code to interact with the database.

We have integrated the vector database with some of the IoT applications and recently, some AI-related topics because it is a cloud-native service. Our company offers professional services to help customers bring their own applications to the cloud. The cost and performance are some of the main benefits of the vector database. 

The integration of the vector database with Azure AI services is great. In most applications right now, we use the logic of vector search and the traditional way of using full-text search. It is easier for the applications to get those search results.

I am more on the presales side. Most of the time, we do a quick demo for our customers. We only spend about fifteen minutes building a simple application with the RAG functionality with the customer's own data. That is very impressive.

It provides good SLAs and requires less effort in maintenance.

The global synchronization feature of Azure Cosmos DB stands out as the most valuable for me. It is a reliable and consistent storage solution, suitable for various data types. It is always available. Additionally, it is cost-effective.

I do not have any specific suggestions for improvements at the moment. However, having more AI capabilities in the future would be beneficial.

I have been using Azure Cosmos DB for three or four years.

The stability of Azure Cosmos DB is very nice, with features like cross-region synchronization that allows fast and reliable performance.

The latency and availability of Azure Cosmos DB are very nice. There are cross-region synchronization features. The speed is very fast.

Azure Cosmos DB scales well, both in terms of capacity and performance. You can adjust the Request Units (RUs) as needed, and the cross-region synchronization allows easy scaling across different locations.

As compared to a traditional RDBMS, Azure Cosmos DB’s dynamic scaling decreases an organization’s overhead costs by half.

We previously used Redis and Postgres for vector databases before they were supported in Azure Cosmos DB. In the beginning, the vector database was not supported with Azure Cosmos DB, so we had to use the Redis or Postgres database, which was expensive. Azure Cosmos DB is cheaper.

Our company offers consulting services for Microsoft-related products. This is one of the reasons for recommending Azure Cosmos DB, but sometimes our customers use MongoDB and other solutions.

The initial setup of Azure Cosmos DB was easy. During the migration or implementation of Azure Cosmos DB, there are sometimes some incompatibility issues, but they are minor issues.

It was easy for our team to use. It took them one week to know the system and work with it. It takes our team members about four weeks to earn their certification for Azure Cosmos DB. There is a special certification for Azure Cosmos DB.

It is cost-effective. They offer two pricing models. One is the serverless model and the other one is the vCore model that allows provisioning the resources as necessary. For our pilot projects, we can utilize the serverless model, monitor the usage, and adjust resources as needed.

I would rate Azure Cosmos DB an eight out of ten. There is room for growth, but Microsoft is constantly releasing new features and moving very fast.

The main use cases involve creating some kind of dashboards in near real-time. Our use cases focus on manufacturing, where we used Microsoft Azure Cosmos DB to maintain data for the very intensive manufacturing processes. In the end, we performed data analysis on the operational processes in manufacturing.

Big data, along with data analysis, is one of the valuable features. We are able to have insights into how to make improvements in the processes for operational people.

Microsoft Azure Cosmos DB is a Microsoft solution specifically, but we can develop with different developer kits for different databases.

We had some performance issues with a data segregation query. We worked closely with Microsoft to solve the problem of performance where, for example, one query had a delay of almost two or three minutes for this one use case. Microsoft tried to improve the product, but in the end, the solution was to change to MongoDB. MongoDB had better performance. We reached the performance required using MongoDB instead of Microsoft Azure Cosmos DB.

I used it for one year or less than one year.

Microsoft Azure Cosmos DB has good performance and latency. We only faced performance issues with the data segregation query.

I would rate Microsoft Azure Cosmos DB a nine out of ten for the capability to scale workloads. 

On a scale of one to ten, I would rate customer service a seven. For example, when I created a ticket with them, they gave us feedback very often, even each week. This went on for four or five months, but they did not solve the problem. They only gave feedback, and in the end, it did not resolve the problem.

Neutral

We changed from using Microsoft Azure Cosmos DB to MongoDB because Microsoft Azure Cosmos DB did not give us the correct performance for certain data segregation, so we replaced it with MongoDB.

People who helped us implement MongoDB were more specialized or had more expertise than Microsoft people.

The setup of Microsoft Azure Cosmos DB was very easy. It took us a few weeks.

We received help from Microsoft directly. They helped us to get started with it. 

Our use case was a failure with Microsoft Azure Cosmos DB, and we do not have any other opportunity to use Microsoft Azure Cosmos DB.

Its pricing is not bad. It is good. 

We have a contract with Microsoft to use their technology. In my opinion, Microsoft Azure Cosmos DB is a good option for the total cost of ownership.

I would rate Microsoft Azure Cosmos DB as seven out of ten.