With Windows SharePoint Services 2.0 and SharePoint Portal Server 2003, The SharePoint capacity planning guidelines had this to state about Document Libraries and capacity
From the “Capacity Planning for Windows SharePoint Services” (For WSS 2.0) administration guide.
In the section “About Capacity and Scale Guidelines”
“Documents – Folder – 2,000 – The interfaces for enumerating documents in a folder do not perform well beyond a thousand entries. “
This was not a hard limit, and many customers were not affected by having many thousand more entries per folder. Until…one day 🙂 When the Database pages lined up just right, the SQL clustered indices statistics were not refreshed, and it was just a very bad day for the SharePoint admin. Then you were in trouble. The only real solution is to reduce the number of items per folder to within capacity planning guidelines. And it solved just about every issue I was ever involved in. That’s why SPSiteManager’s analysis routine checked all capacity planning guidelines. We could easily identify “Where” to go look.
For Windows SharePoint Services 3.0 and Microsoft Office SharePoint Server 2007 (MOSS) the capacity planning guidelines where changed “Slightly”
From the “Plan for software boundaries (Windows SharePoint Services)” Technet article
“Throughput differences between flat document library vs. document library with folders
Throughput for certain operations decreases as the number of items in a folder increases.
The following figure shows the difference in throughput between viewing all items in a document library with and without the effective use of folders, which is critical for scaling. As shown in the graph below, throughput performance degrades as the number of documents increases when flat library storage is used. The quickest drop in throughput occurs when the total number of documents is less than 2,000, from 151 RPS (at 200 documents) to 63 RPS (at 2,000 documents). At 4,000 documents, throughput decreases to about 13 RPS, or an overall throughput decrease of over 90% from an empty library.“
Note: Remember MOSS is built on top of WSSv3 just like SPS 2003 utilized WSSv2 as the platform, so this applies to MOSS libraries as well.
That statement is followed by a table much like the old V2 capacity planning guidelines with the following for Document Libraries
“Document – 5 million per library – You can create very large document libraries by nesting folders, using standard views and site hierarchy. This value may vary depending on how documents and folders are organized, and by the type and size of documents stored.”
I believe it’s worded this way specifically because the “2000” item statement for folders before was a not a hard limit, and the purpose of the updated guidelines is to stress that this is not a hard limit, and testing showed the performance degradation (And a cool chart!) with the total number of items, not that the minute you add that 2001th item to your folder that you were going to be in some serious pain :). The 2000 item limit was more on the “View” side of things. (Go look at the old docs, you’ll see).
The new guidelines have this to state about views:
“Item – 2,000 per view – Testing indicates a reduction in performance beyond two thousand items. Using indexing on a flat folder view can improve performance. – List view”
So there is a bit more separation on the limits for “Views” versus “True Item counts”, but remember, a File in a a Document Library is really just an Item in a list. Its just a reversal when your comparing Document Libraries to Lists (List items have metadata and file attachments, Document Library items are really just list items with metadata, and a blob of data). The point is, that “View” performance cannot be truly compared to overall “Document Library” performance, but your items within a folder are going to directly affect your view performance. Clear as mud? 🙂
Again, when SPSiteManager reported these exceptions to capacity planning guidelines, it was done with a “Warning” element, not a “Oh my goodness!! Do something quick!” element 🙂 But the importance of that call out was there. It’s point was to show you where you may want to start investigating restructuring of your content.
So, back to the question “Can you really have more than 2000 items per folder in SharePoint now?”
The answer is, “You could always have more than 2000 items per folder in SharePoint, even back in WSSv2/SPS2003. It boils down to acceptable performance, even in WSSv3/MOSS2007.”
Well, that’s “My” answer 🙂
Remember, the new capacity planning documents state:
“This value may vary depending on how documents and folders are organized, and by the type and size of documents stored.”
The debate will probably never end, as it depends on a wide variety of factors before you “May” be impacted by this, but if you want my opinion on what you should limit your document library folder contents too? Keep them no larger than 2000 items per folder. The same goes for List Items within a list folder too. This is “My” opinion, and not a direct statement from Microsoft. :).
I would highly recommend that you subscribe to and read Joel Olesons’ blog at http://blogs.msdn.com/joelo. He’s got TONS of data on this subject linked from his blog.
Ah, I remember the days of sharing emails with “Dances with Goats” back and forth on capacity planning, and the joys there of. Joel, I miss ya buddy, but I’m still watchin’ ya :).
Till next time!
– Keith Richie