Google Cloud SQL

Best suited for Financial services, banks, eCommerce, telecom companies products where more relational database kind of data is required and where we want to migrate from legacy system to cloud world.
But, I guess it would not be useful for IoT, analytics, real-time processing of data, etc. Where big data is more prominent.

For a general purpose SQL database, it's very well suited, performant and secure, if you already use GCP.
If you intend to connect from other BI, analytics or 3rd party tools, I advise to check if they support SSL to Google Cloud SQL, because most don't. If you are on AWS, go with RDS

It is a very powerful database service. It can be easily set up even by an entry-level developer. It can be used by medium to large organizations in their various projects. It can be used by business apps as well at any level. It can also be used where latency is an issue as It is extremely fast

[Google Cloud SQL] is a big help for IT administrators to ensure the security of databases and data backups as well as replacing replica databases in failover situations, It is very powerful and fast in managing and migrating databases and it only takes a few minutes to create and connect to your first database using the built-in migration tools.

Overall, Cloud SQL serves all of the needs we need it to. It can do everything a relational database can do, plus it is completely managed so you don't have to worry about the size of the VM, partitioning, etc.

Customer service has always been helpful and responsive when asked about Cloud SQL specific issues.

Google Cloud SQL was very easy to setup because our institution is already already invested in the Google Cloud Platform. If we had gone with Amazon or Azure, there would have been extra complexity and cost of getting established. The product is a great fit for organizations already invested in GCP. Google offers everything the others do, however third party vendor support is seriously lacking (aka the vendors refer you to other tools like AWS etc).

GCP support in general requires a support agreement. For small organizations like us, this is not affordable or reasonable. It would help if Google had a support mechanism for smaller organizations. It was a steep learning curve for us because this was our first entry into the cloud database world. Better documentation also would have helped.

Google Cloud SQL is a great resource for some purposes, but it's probably overkill for others.
In cases where a database is not always needed (on sometimes, off others), it would be better to use a traditional software installation. If database needs are relatively small, software installation will perform just as well and be easier to support. If a database is only needed in one physical site or a small geographical region, it's better to use a regular server based installation. But as soon as a project has greater database needs, Google Cloud SQL is a great choice. Consider using it if any of these apply:

• A large amount of data (10+ GB).
• Decentralized access (many worksites, end-users, etc.).
• Uptime and reliability are required.

Support for Google Cloud SQL is much like support for any other Google Cloud resource. There is extensive documentation from Google and some from the outside community. Google also provides surprisingly effective on-page tutorials to help when starting out. For anybody who is technically inclined, this will be more than enough to get started, the rest is just good old fashioned database administration.
If personalized support is required, as with all Google Cloud resources, a paid support plan is required. This can be frustrating, but given the uniqueness and complexity of the platform for individual users, this is probably not avoidable.

For any serious production setup, where "serious" means aware of the importance of having automatic/secure backups, a good recovery plan, high availability options and managed DB server maintenance, I go with this solution before any self-managed option.

I'd be cautious if I need too much processing power or storage available for my DB. On these cases, I'd first think again about my selected DB architecture, and then analyze some options to calculate ROI of each investment.

I haven't used support for this product since I deployed my first instance. After running it for some years, the docs have always been enough to solve any problem I had encountered.
But speaking about the vendor, Google Cloud support answered well and in an acceptable time to the few issues we needed to get assistance for.

It is great if you don't want to worry about managing hardware and infrastructure and instead focus your efforts on work directly related to your product's database needs, i.e. schema design, efficient queries, etc. However, if you are dealing with very large data sets, then BigQuery, BigTable, or similar might be better suited for your needs.

Google Cloud SQL provides the two most popular open source SQL servers, does everything right, and can be used for most use cases. It can be used for most business applications and at any scale, as Google Cloud SQL can scale very well based on the application needs. It's less appropriate for applications that use a DB other than MySQL and PostgreSQL, and for apps that don't need data persistence.

When you need relational storage.
Not when you need warehousing.

If you're hosting a site on Google Cloud, it only makes sense to make use of Google Cloud SQL for the database, as opposed to running a separate MySQL service on a VM. It's extremely fast and has resulted in a dramatic improvement in page load time across multiple sites.