I have a client that currently uses a local Advantage Database on their PC along with an application. They are thinking of upscaling their setup to have multiple applications running communicating with a database server i.e/a client-server environment.
They are now considering the best database for this approach. They are looking at the Advantage Database Server product in comparison to SQL Server Express(the application does not warrant a full SQL Server at this stage).
Obviously SQL Server is a more well known product probably with more support but I was hoping you could give me some opinions and thoughts on what you think the best product would be in terms of performance, stability and support.
One thing to note although not directly relevant is that the application is currently written in Delphi and there could be a move to C# to bring it up to date.
The migration from a local Advantage Database to a client/server Advantage database is a very simple process. It simply involves changing the connection properties within the program. There are no other coding changes that need to be done.
Advantage has a great support team and has been in development for over 15 years. The stability and support are at least equal to SQL Server.
Advantage also provides a .NET Data Provider which would allow for C# development.
I have developed for both SQL Server and Advantage. They each have their pros and cons (although now I favor Advantage).
Given your situation, however, this decision appears to be a no-brainer: Advantage Database Server. Why? It's already done!
My Advantage programs run, unmodified, against the same database either locally or remotely. All I change is the connection string. I'm not saying that your customer's code won't have to be changed. I am saying it is likely to be trivial. Compare that to the greater effort involved in switching to a whole new database engine.
In general I'm a SQL Server person all the way. I work with id daily and have for almost ten years, but in your situatuion, it seems silly to consider moving to a new database when there is aclear upgrade path to do what you want using the backend you already have. It would be much less work and far less likely to introduce new bugs to stay within the same database family.
ADS wins hands down. It is maintenance-free. It is extremely reliable. It is extremely fast. It is extremely scalable. SQL is very well supported, and the ADS newsgroups are responsive (answers within hours instead of days on SQL server fora) and well-informed. I have been using ADS since 1991 and it has never gone wrong! My users are incredibly demanding and to be able to turn round solutions within hours instead of days, is both a joy to me and a business incentive to the end users and clients. Deployment is gentle, fast and simple. Platform support is better than SQL server. 64-bit server deployment abounds and is well-grounded, transparent and reliable. 64-bit clients are coming in the next version (10). My experience with ADS is wholly positive, whereas my ventures with SQL server have been fraught with difficulties, idiosyncrasies and workrounds!
I happen to be a support rep for Advantage so when you say "Obviously SQL Server is a more well known product probably with more support" I have to argue a bit.
As Chris stated switching from Advantage Local Server to the the Advantage Remote (client/server) Server is a pretty painless process - they designed it that way.
Install the Advantage Database Server on a machine where the data is located (not a requirement but it's recommended). You can get a free trial here: http://marketing.ianywhere.com/forms/ADS91-30-Day
Within the application there will be TAdsConnection component(s) - change the TAdsConnection.ConnectionType to 'REMOTE' (http://devzone.advantagedatabase.com/dz/webhelp/Advantage9.1/mergedProjects/ade/sec7/connectiontype.htm)
You can specify the path (TAdsConnection.ConnectPath) from the clients in a couple different ways but the recommended is:
\\server:6262\mydata
http://devzone.advantagedatabase.com/dz/webhelp/Advantage9.1/mergedProjects/ade/sec7/connectpath_tadsconnection.htm
Note: 6262 is the port used by default (may need to add an exception to the firewall). Also if your application uses a data dictionary the path would include the name of the .ADD file (e.g. \\server:6262\mydata\mydd.add)
Hope this helps!
Related
I have a number of MS Access databases that range from the simple to the fairly complex. They exist as split databases on a shared drive on an on site LAN and the users all have accdr front ends to work with.
Until Covid 19 this worked quite well, now we all have to work from home. While I expected some performance issues, I did not quite expect performance to take quite that much of a hit. So I am looking for ways to migrate to something that will work well with everyone trying to work via a VPN.
An additional fly in the ointment is that there is no budget to work with and getting IT support is akin to summoning the great old ones (it's difficult and you are likely to die insane).
So I have begun to research some different options. MS SQL Server has come up, but I don't know very much about how to implement it. I do not have a dedicated machine to put this on.
I have looked at Sharepoint, but some of the stuff I have been reading makes it seem like this is not a great option as some of my queries are complicated and I have some pretty large tables (45k records, 100 fields per record) In the most complex DB, I have to add several thousand records each day and run several update queries on the freshly added records.
MS Azure looks promising, but again I don't know if that will put me at odds with the malevolent IT gods.
I started looking at office 365 Power apps, but I don't need any mobile device support and it doesn't look like it has the Oomph I need.
Google and Duck Duck Go haven't thrown up anything usefull that I could find among the dross. I'm certain what I need is out there, I just can't find it. I have found that One drive is right out, and likewise Sharepoint for anything other than the simplest DB I have built.
What I am looking for is any solutions, articles, books or even papyrus scrolls and stone tablets that might get me pointed in the right direction. Any Ideas? Any other information you need?
Edit: After so looking I have found that I may be able to get MS SQL server on a virtual server without angering the IT demons. Azure as a solution is out unless I find a suitable sacrifice. Any good places to look for information on how to use SQL server from a standing start?
Consider migrating the backend databases to SQL Server. There's a SQL Server Migration Assistant that will do this for you. Your frontend will contain links to the resulting SQL Server tables.
The last time I did this I got an immediate 2X performance improvement on a LAN. Over a VPN, you should expect similar, possibly better, performance improvements. Quite a good win for something so simple to do without having to do a full rewrite. Don't expect miracles however; Access by nature is a very thick client.
You don't necessarily need a full-blown SQL Server; SQL Server Express should suffice, and you can run that on any machine on your LAN. The download for SQL Server Express Edition can be found here.
You can read up on the migration process here.
You should consider using Remote Destop Connection first!
As you already managed to connect employees by VPN to LAN, you just need to enable remote access to their machines at work! That is the simplest solution and it doesn't need a fast connection or any changes on the application. You can enable WOL so they can turn on machines themselfes.
Of course you should also consider migrate to a RDBMS like Robert advised!
We are a small team of 5 working on a same database. It's a reporting solution so there is about 5 more 3rd party databases which is source of data.
It is very important to have latest data for development, so sometimes those linked databases backed up and restored on each dev's local SQL Server(an they pretty big). Then there is always a problem with dev's databases being out of sync from each other. When it was 2 of us, there was no problem. But when more people got added to the team - it starts to be a pain to arrange.
So, I was thinking about building a dev SQL Server. It will be more powerful then laptops (faster queries) and latency should not be an issue. We always have internet when working and that is not a problem either. I only wonder if it's OK to work together out of the same database. Sounds like a good plan, but not sure if there will be any "gotchas" comparing having databases locally. We will be able to keep data fresh for everyone easy. And I think it should save time and making easier to build/rebuild dev machines if needed. I even think that database where we code can be 1 per person, but still on a same box. This way we can always compare them "right on a box" if needed.
Any advices on this setup? Pro's or Con's?
A new option is to use isolated containers on a shared server, with clones of the production database environment. Full disclosure, I work for Windocks, where this is the primary use of SQL Server containers. The most recent release includes built-in SQL Server db cloning. Benefits of this approach include speed (environments deliverd in <1 minute), and license and labor savings by going to a shared server rather than a score of VMs.
So I'm thinking of dipping a toe in the Azure pool
Our web App Suite will soon be a pure ASP.Net + SQL Server affair
For various reasons it will be simpler to initially create a SQL VM and run everything from there initially.
How hard will it be to ...
...migrate SQL off the VM and into either "Cloud Services" or "Data Management"?
...migrate the suite of WebApps off the VM and into "Websites"?
It is my understanding that having achieved this migration, the OS level updates will no longer be my concern as they will be handled by the service. Thus at this point I'll be able to throw the original VM away :)
This isn't exactly answering your questions, but it might help educate you on more questions to ask and giving you a boost out of the gate. These were all lessons learned before, during, or after our migration of our systems to Azure. Now that we're up there, we have a ~50GB database with ~6 services running across ~30 instances. As long as our database backup behaves, total amount of effort in upgrading all of this is less than an hour (and could be much less if we didn't have many safeguards meant to force us to be aware of what's going on during the migration process - we don't want it to be too easy to deploy just to protect us from ourselves).
Preparing to migrate your system to Azure:
If you're planning to go to Azure, you first need to make sure your architectures and technologies are compatible. This isn't to say you have to code everything specific to Azure. This means some of the following things:
You should realize that "high availability" does not mean "error-free". In fact, high-availability environments usually have more errors that you have to handle and manage. For example, if you have a request going over the network to a server that just had a motherboard fry and was taken offline, that network request will be unsuccessful. That's not typically a problem you code for in "standard" server apps. To take it even further, what if that failed network is for a Database Connection that gets put back into a connection pool? That will cause that connection to be poisoned and broken the next time somebody pulls it out regardless of the future state of that server that went poof! There are just some extra things to worry about here because you're no longer depending on just 1 network with 4 servers on it but are now depending on hundreds of networks with thousands of servers on them. That 0.05% error scenario will happen MUCH more often to you than you've ever experienced in the past and you really have to be aware of this!
You should use dependency-injection to easily change things around. Proper separation of concerns will changes that seem very difficult become very easy in Azure.
You should use architectures for "high-availability". For example, a web application that would break when ran in a web farm would also break in Azure but a web application designed to work in a web farm would be very easy to run in Azure.
You should have automated deployments and configuration transforms for all of your applications. Anything else is just unsustainable unless it's nothing more than one little web site or something like that.
Depending on your needs, you can do it in phases. If database latency is something that isn't a big deal, perhaps a hybrid approach (over VPN from Azure to your data center) is acceptable to get your apps in Azure first while you later migrate your database. Or perhaps the opposite. What we did was keep primary apps and database in our data center but put secondary apps up in Azure first. Then some primary apps (that took a performance hit for a month until) later our database and critical apps. That final migration sure made for a very long weekend and not much sleep, but it is SOO much nicer now that we're done!
Migrating your applications to Azure:
This ultimately depends very heavily on what your application is or does, and every scenario has different steps/issues/benefits. I'm not going to cover this deeply other than to say, "Use Google, it's your friend!". Beyond that, for us, getting our applications up into Azure was the largest payoff when compared to our data. The ROI on our app migration was less than a month between hosting costs, licensing, and management effort. Instead of taking a couple days to setup a server, I can now take a day to setup an entirely new and duplicated environment of all of our SaaS applications/databases/etc and have them running on ~25 different Cloud instances!
Instead of trying to tell you how to migrate these, let me give you a few words of caution so you know sooner rather than later:
If you have app problems in Windows 2012, humor me and try it in Windows 2008 R2. There are a couple bugs in some of the 2012 images that they've prepared. It's incredibly trivial to switch back and forth!
Go make your logging 1000x's better than what it is now. If you don't do that now, you'll regret it.
Don't depend 100% on the easy-to-implement "Azure Logging". It works well enough but it more-or-less requires your applications to start successfully and is absolutely useless in debugging startup problems. If you don't have an alternative, then you will waste many, many hours just debugging stupid little problems when your app starts up. By the time you're done with it, you could have easily added 5 other logging frameworks and had an amazingly awesome logging system in place plus a running app instead of nothing but a running app to show for the same amount of time. Really, do this! (Profiling is a good idea as well, although Mini-Profiler has load-balancing issues if you have multiple instances.)
If you add new endpoints to your deployment (ports, etc), you cannot simply "Upgrade" an existing deployment. You must delete it (the deployment, not the service) and install from scratch. You can delete the Staging one, deploy to Staging, then swap.
If you have WCF apps, pretend you don't know about Windows Activation Services. They're disabled in Azure by default. You can either hack them to turn them on (startup scripts) or create your own self-hosting application. We self-host so we can more easily tweak service configurations once we're deployed (it's not easy to edit web.config files in a way that sticks in Azure). Web services work in "IIS" in Azure but TCP, named pipes, etc. do not.
Go learn about and add the Transient Errors Application Block (or something equivalent) to anything you communicate with. If you don't do it now, you'll regret it.
Go make your logging better! Really, really, REALLY do this!
Migrating your SQL Server Database to Azure:
Getting your database up into Azure is a bit of a painful process. There isn't a quick and easy way to just get it up there and making it work. Some people have to make some major changes while others just have to tweak a few ignorable things here and there. However, no matter how large or small your database is, you really REALLY must devote a lot of time to testing it. Test your migration process. Test your scripts to prepare your database. Test the performance and stability of the database up in the cloud. Test your backup procedures. Test your upgrade procedures. Test your backup restoration procedures. Test ALL of this because I guarantee you that you will find some surprises!
Schema:
Go learn about all of the limitations of SQL Azure. No Heaps, etc. Learn them before you start! Go learn them now! They're all mostly to very reasonable.
Be aware of the 2GB T-Log limitation! This means some very large indexes can never be rebuilt! (that said, our 30GB table isn't yet hitting this)
To deploy your schema, go into SSMS for your local db and use the "Tasks -> Extract Data-tier Application..." feature (it's in different areas of the menu in different versions of SSMS). Take this file and go into SSMS for your Azure database and use the "Deploy Data-tier Application" feature. (This will help you catch some of the Azure limitations you aren't honoring if this process fails.) This is, by far, the easiest way to get an empty version of your database up into Azure.
Use a tool like Redgate SQL Compare to verify your work (you'll have to tweak a couple options, like WITH NOCHECK to get a clean comparison).
You'll have to cleanup users, schemas, broken sprocs, etc. before you succeed at this. (this is a good thing!)
Data:
Go learn about all of the limitations of SQL Azure. Learn them before you start! Go learn them now! They're all mostly to very reasonable.
Go download the Azure Database Migration Wizard from Codeplex (or wherever the latest version is). It's not the most amazing software (kinda unstable) but even if it crashes once or twice on you, it'll still save you a LOT of time!
I strongly recommend RedGate's SQL Data Compare. The previously-mentioned migration wizard will help you identify problems (it's on you to fix those) and will get you ~98% migrated but you'll want to come back and clean up after it. It has some bugs that misses nullable BIT fields (and upper ascii characters) and some other things that a tool like SQL Data Compare can easily identify and fix. It can also give you the peace-of-mind that you can depend on your database.
If your database is large, consider spinning up a temporary VM in Azure (they have them with SQL Server pre-installed and available in ~20 minutes) to do your migrations from. If you do this, it's best to upload a compressed database backup to Blob storage (Cerebrata's storage too is great for this) and then grab it and restore to SQL Server in that VM. Then stage your migrations all from there!
Test, test, TEST!!!
Be careful running SQL on a VM, it's not a high availability solution. Azure VMs are prone to restarting from time to time. Unless you have multiple VMs running SQL Server in an availability group, or you have some sort of mirroring and load balancing setup, you won't have a high availability solution. I too originally favoured the IaaS to PaaS route, in the end it seemed to be a false economy as migrating IaaS to PaaS is about as much work as migrating on-premise to PaaS. In the end I decided to take the time to optimise my application for PaaS, i.e. moving durable storage to blobs, implementing transient error handling and retry logic, etc.
What you're proposing is certainly possible but having a multi VM arrangement to deliver high availability SQL takes a bit of work and is expensive! Have a read of the following guide, it was really helpful to me when I started the migration process:
Top 7 Concerns of Migrating a .NET Application to Azure
Just yesterday Microsoft announced their plan to host also Iaas solutions and not only Saas solution on their Azure platform.
http://weblogs.asp.net/scottgu/archive/2013/04/16/windows-azure-general-availability-of-infrastructure-as-a-service-iaas.aspx
About migration, it really depends. We work with a distribution mechanism: TFS + Octopus so the deployment is very easy and it works on Iaas or SQL Azure, it doesn't really matter.
There are also other things to keep into consideration when moving into Saas. Probably your code should be refactored if it's not Saas oriented or your application may have a very high hosting cost over Azure.
I have a client who wants to develop an application using Access 2007. For the stated short term purposes, Access 2007 fits their specification:
approx 30K master records
6 or fewer users
department file server
The issue is that the client is very technically naive and isn't at all aware of the trouble they might get into if the scope increases. The application will be storing master data that will be uploaded into an enterprise system and I fear that six months from now I'll be hearing any of the following issues:
we need to keep all of the historical data (suddenly we have 3M rows)
we need fine grained and airtight user level security
we keep getting corrupt data records
our database wasn't backed up for three months (because a user kept it open)
I've done a few small Access databases but I'm a SQL server dev by trade and I know how to use it to solve most any problem. I don't know if my client should be worried about their choice of technology - and if they should, I'm not 100% sure how best to communicate the risks to them.
I fear that six months from now I'll be hearing any of the following issues:
we need to keep all of the historical data (suddenly we have 3M
rows)
Three million rows isn't necessarily a deal-breaker for a Jet/ACE data store. Depends on amount of data in each of those rows.
we need fine grained and airtight user level security
This is a compelling reason to move data storage to client-server db.
we keep getting corrupt data records
That should almost never happen with a proper Access implementation, contrary to claims by Access bigots. It will happen if you're running across an unreliable network. But, if that's your client's situation, you should either fix the network problems or ditch Access for data storage.
our database wasn't backed up for three months (because a user kept
it open)
You can build on Arvin Meyer's KickEmOff approach. But with <= 6 users currently, it might be easier to deal with the situation without code for now. Just ask them to close out long enough for the backup. You could have your automated backup routine create a notice when its attempt fails, so this shouldn't have to be a constant thing.
In any case, suggest you design the current application so that an eventual migration to SQL Server will be less troublesome. Avoid Access-specific features: hyperlink data type; lookup fields; multi-value fields; attachment fields; and so forth. Since you're experienced with SQL Server, it should be fairly easy to create a test SQL Server database and link a copy of your Access front-end to it. Test periodically as you develop the Access front-end. Then you look like a hero when the client recognizes a need to move the data storage to SQL Server.
I'm in a mixed Sql/Access dev shop and understand your concerns, but the sheer usability of Access often wins out for users. Where we have mission critical data and need to use Access we simply used Linked tables - best of both worlds, Sql handles Security, Backups etc and Access provides the front end.
To me, the obvious answer is to develop an Access front end to an Access back end for the initial implementation, but doing the development with upsizing the back end to SQL Server in mind.
That means just applying commonsense to what you do, as #HansUp suggests (i.e., not using Access-specific functionality), and designing your data retrieval so that it will work well with a server back end.
If, on the other hand, either the increased amount of data or the security issues are actually not just remote possibilities but likely to become issues during the lifetime of the app, I'd go with a SQL Server back end from the beginning. But your description of the situation really doesn't sound like that's the case at all.
Certainly the corruption and backup concerns are completely misplaced. Proper maintenance and backup has to be in place, and the operating environment has to be stable, but all of that applies to any database engine, not just to Jet/ACE.
Explain to your client that you will have to charge much more money to create, implement, maintain, repair and later upsize the application. Explain that they will not save money in the long run and that they will be better off if they go ahead and allow you to properly prepare now. That being said, I agree with #HansUp suggestions. You can give the customer what they want and still prepare for the likely eventualities. Think of it as job security.
There are Price and GUI advantages to using Access over SQL that for the non-technical people are really attractive. I think given your scenario then maybe the "customer" is right - aren't they always!
However, your 4 "following issues" really answer your own question.
If your user is technically naive then there is not much point in using technical language. If at all possible when l speak to users the language and terms I used are the same my users understand. Also compliment your users when possible it makes them feel good and make you look good in their eyes. Here's some suggested ideas.
Using Access 2007 is an excellent idea, easy to develop with and change to met your needs. However there are a number of very strong technical reasons for using another free tool, namely SQL express to store the data.
Why use SQL express?
Its free !
Security of the data will be a very high priority (even if client has not mentioned this use this as a reason). Point out how easy it would be to steal all the data from Access compared to SQL server. See this book for excellent detail regarding Access security. The user level security for SQL server is much simpler and easier with SQL server, and will cost less money to implement, as well as being more secure.
Backing up of data. In order to back up the access database no one can be using the database or even connected to the database. With SQL server can back it up at any time. Less down time or in other words greater productivity using this other FREE tool.
Data corruption. One issue with Access database, is corruption of the database. What does this mean? It is possible to lose up to a days worth of work, with SQL server this issue is much very much less likely to occur. There are even situations where it is not possible to recover the database. Hence this loss of productivity can be minimised if using SQL server.
When this tool gains greater recognition and other departments wish to use it, as no doubt it will. Moving to a larger enterprise database system will be much easier and less costly to develop, if you use SQL server express as the data store.
The above are just suggestions, based on the assumption you user is wishing to expend as little money as possible, and the limitations / resources you put in your posting.
I also appreciate that not every one will agree with what l have put in the suggestions above. They are not meant as detailed technical points, more as suggested ways of persuading a technically naive client to consider using SQL server express as the back end db for an Access db used for a departmental application
Is there a general rule of thumb to follow when storing web application data to know what database backend should be used? Is the number of hits per day, number of rows of data, or other metrics that I should consider when choosing?
My initial idea is that the order for this would look something like the following (but not necessarily, which is why I'm asking the question).
Flat Files
BDB
SQLite
MySQL
PostgreSQL
SQL Server
Oracle
It's not quite that easy. The only general rule of thumb is that you should look for another solution when the current one can't keep up anymore. That could include using different software (not necessarily in any globally fixed order), hardware or architecture.
You will probably get a lot more benefit out of caching data using something like memcached than switching to another random storage backend.
If you think you are going to ever need one of the heavyweights (SqlServer, Oracle), you should start with one of those at the beginning. Data migrations are extremely difficult. In the long run it will cost you less to just start at the top and stay there.
I think you're being overly specific in your rankings. You can pretty much start with flat files and the like for very small data sets, go up to something like DBM for slightly bigger ones that don't require SQL-like syntax, and go to some kind of SQL database after that.
But who wants to do all that rewriting? If the application will benefit from access to joins, stored procedures, triggers, foreign key validation, and the like--just use a SQL database regardless of the dataset size.
Which one should depend more on the client's existing installations and what DBA skills are available than on the amount of data you're holding.
In other words, the size of your database is far from the only consideration, and maybe not the most important one.
There is no blanket answer to this, but ALMOST always, using flat files is not a good idea. You have to parse through them (i suppose) and they do not scale well. Starting with a proper database, like Oracle or SQL Server (or MySQL, Postgres if you are looking for free options) is a good idea. For very little overhead, you will save yourself a lot of effort and headache later on. They also allow you to structure your data in a non-stupid fashion, leaving you free to think of WHAT you will do with the data rather than HOW you will be getting it in/out.
It really depends on your data, and how you intend to use it. At one of my previous positions, we used Postgres due to the native geo-location and timezone extensions which existed because it allowed us to manage our data using polygonal datatypes. For us, we needed to do that, and we also wanted to use stored procedures, views and the like.
Now, another place I worked at used MySQL simply because the data was normalized, standard row by row data.
SQL Server, for a long time, had a 4gb database limit (see SQL Server 2000), but despite that limitation it remains a very stable platform for small to medium applications for which the old data is purged.
Now, from working with Oracle and SQL Server 05/08, all I can tell you is that if you want the creme of the crop for stability, scalability and flexibility, then these two are your best bet. For enterprise applications, I strongly recommend them (merely because that's what we use where I work now).
Other things to consider:
Language integration (ASP.NET session storage, role management, etc.)
Query types (Select, Update, Delete) [Although this is more of a schema design issue, not a DBMS issue)
Data storage requirements
Your application's utilization of the database is the most critical ones. Mainly what queries are used most often (SELECT, INSERT or UPDATE)?
Say if you use SQLite, it is gears for smaller application but for "web" application you might a bigger one like MySQL or SQL Server.
The way you write scripts and your web application platforms also matters. If you're developing on a Microsoft platform, then SQL Server is a better alternative.
Typically, I go with what is commonly accepted by whichever framework I am using. So, if I'm doing .NET => SQL Server, Python (via Django or Pylons) => MySQL or SQLite.
I almost never use flat files though.
There is more to choosing an RDBMS solution that just "back end horsepower". The ability to have commitment control, for example, so you can roll back a failed transaction is one. reason.
Unless you are in the megatransaction rate application, most database engines would be adequate - so it becomes a question of how much you want to pay for the software, whether it runs on the hardware and operating system environment you want, and what expertise you have in managing that software.
That progression sounds painful. If you're going to include MS products (especially the for-pay SQL Server) in there anywhere, you may as well use the whole stack, since you only have to pay for the last of these:
SQL Server Compact -> SQL Server Express -> SQL Server Enterprise (clustered).
If you target your app at SQL Server Compact initially, all your SQL code is guaranteed to scale up to the next version without modification. If you get bigger than SQL Server Enterprise, then congratulations. That's what they call a good problem to have.
Also: go back and check the SO podcasts. I believe they talked about this briefly.
This question depends on your situation really.
If you have control over the server you're deploying to and you can install whatever services you need, then the time to install a MySql or MSSQL Express server and code against an existing database framework VERSUS coding against flat file structure is not worth the effort of considering.
What about FireBird? Where would that fit into that list?
And lets not forget the requirements that the "customer" of your solution must also have in place. If your writing a commercial application for a small companies, then Oracle might not be a good choice... but if your writing a customized solution for a large enterprise which must share data among multiple campuses, and has a good sized IT department then the decision of Oracle vs Sql Server would come down to what does the customer most likely already have deployed.
Data migration nowdays isn't that bad since we have those great tools from Embarcadero, so I would instead let the customer needs drive the decision.
If you have the option SQL Server is a good choice from the word go, predominantly because you have access to solid procedures and functions and the database backup facilities are totally reliable. Wrapping up as much as your logic as you can inside the database itself (rather than in whatever language you are using) helps security and performance - indeed there's an good argument to be made for always using procedures for insert/update logic as these make you invulnerable to injection attacks.
If I have the choice the only time I'd consider MySQL in preference is with a large, fairly simple, database predominantly used for read access. This isn't to decry MySQL which has improved markedly of late and I happily use if I don't have the choice, but for more complex systems with update/insert activity MSSQL is generally the superior option.
I think your list is subjective but I will play your game.
Flat Files
BDB
SQLite
MySQL
PostgreSQL
SQL Server
Oracle
Teradata