I am currently architecting a large SharePoint deployment.
This deployment has the potential to grow to petabytes in size over the course of several years.
One of the current issues we are discussing is the option of storing our data in SharePoint using InfoPath Forms. Some of these forms contain hundres of fields and require a lot of mapping to content types for persistence and search. Our search requirement is primarily a singular identifier and NOT the contents of the forms, although I am told I should preempt the "want" to search in the future.
We require our information to be utilised for secondary purposes (such as reporting etc). The information MUST be accessible instantly after persisting to the system.
My core questions therefore are:
- What are the benefit/risks of this approach compared to storing our data in a singular relational store using web-service persistence?
- If we decided on this approach what would be the impact of changing the forms, content-types over time?
- What happens when our farm grows beyond a single web-application / site collection how accessible will the information be? Will I know where it is and how portable will the information be overtime?
This is going to be a long one and may not have an answer just because there's no silver bullet for what you're looking for. It's mostly insight and ultimately the choice is up to you.
This statement throws me a little. SharePoint data is stored in SharePoint (well, SQL technically) but InfoPath is just a UI layer for accessing any part of that data.
From this I assume there are multiple forms which would mean different types of data being accessed (and probably different purposes). Hundreds of fields is no problem and it really boils down to managing the form and view design.
From the form side you should check out cxpartners form design crib sheet. This gives you a nice standard to follow to manage all those fields. Another thing would be to look at breaking the form up in tabs or views itself (in InfoPath) based on what the user needs to fill out. Basically it breaks down to not creating a form with 100s of fields on one massively scrolling screen the user will just freak out over.
Same with the views on the form or document library you're storing the form data in. InfoPath forms are just xml stored in a library (so regardless of how many fields you have, the footprint is pretty minimal). You don't want to map and surface every field in the form nor do you want to have a view with 100 columns on it. You should look at breaking down the views as they're fit for purpose, with only a few hundred items in each view with a few columns. It's a balancing act too as you don't want to create 100s of views either so you need to find out what's right. A good B.A. or Information Architect will help with this with the SharePoint/InfoPath guru and business user helping out.
This is another requirement that's going to be a little difficult to meet exactly. If the library has thousands of items (or 10s of thousands) and a view has dozens of fields then expect the view to come to crawl (especially if the user is insistent on "seeing everything" and wants the limits of each view to be set to 1000 items, like anyone could process that much information at once). Instant access is difficult if you're keeping everything online for a long time (like for reporting). There's the operational side where users are filling out forms, finding forms, editing them, etc. and for that you only want a few hundred items to be live at any given moment (up to a few thousand but you need to be careful on the views). If you have a list with 100,000 items in it and users are using this for daily activities and trying to run reports for trending or long term operations against it, you're going to lose the performance battle. Look at doing reporting offline, potentially shipping the data that's reportable to a second source like SQL and using SSRS against it. Performance Point is an option but adds a layer of complexity to the architecture. The question will ultimately fall to what reporting looks like and how important is it in relation to daily operations.
To try to answer your questions directly:
The benefits to using SharePoint over a database are that the data can be easily viewed and sliced and diced up. Creating a view is child's play and can quickly show you useful information like # of sales in a month or customer feedback grouped by call centre person. SharePoint makes it easy to view this information and even setup dashboards, hook in KPIs, etc. without having to get some developer to craft custom web pages. As far as risks go, you need to be careful with letting things grow organically and out of control. Don't let the users design views of data, they generally want something but not sure and will ask for all columns to be available which they just export to Excel to slice and dice. Make sure there's a good design around the views and lists and they're fit for purpose and meet what needs the user is trying to get out of the data. Ask the question of what they're looking for and why, that will help shape what to expose.
Any change needs to be thought out and planned and tested. It's no different in SharePoint if you add a column to a list as you would by adding a column to a SQL database. Form updates should be considered and while you won't get it 100% right the first time, you should try to get as much as possible without going overboard and putting in crazy things like 100 "blank" fields that are players to be named later. Strike a balance by understanding the needs of the users and company and where things are going. Hopefully someone will have a vision of what this thing might be when it grows up and that'll go a long way to understanding the impact of change.
Data is just xml and as long as you're not doing stupid stuff in the form like hard coding absolute paths to services (use data connection libraries) the impact of growth will be minimal. Growing beyond a web application into multiple ones is a pretty big change and not something to be taken lightly. Even splitting site collections out is big and there needs to be a really good reason for this. Site collections can handle thousands of sites and millions of documents without issue. Web applications are really there for dividing up areas of interest or separation of purpose (like team sites on one web app and a publishing portal on another) and not really meant for splitting data due to growth concerns.
Like I said, there's no silver bullet here and what you're asking for is an architecture for a solution that nobody here has all the requirements for. Hope this helps.