Following on from customer related issues in Office 365, there are a number of technology issues that give me concern. I will caveat this that this is based on my last project, and by the time I write this the Office 365 SharePoint platform could have changed to address some of these problems. Continue reading “Observations on Office 365 – Part 2”
QueryThrottling
What happens with a large TaxonomyHiddenList?
SharePoint’s Taxonomy (or “Managed Metadata”) fields are a bit strange in how they work. In a lot of ways they’re actually like a lookup field, and part of this lookup field is that site collections that use them have a hidden list – called TaxonomyHiddenList – in the root of the site collection. You can find it at /lists/TaxonomyHiddenList/.
Each term that is used in a Taxonomy field has it’s label (actually, labels) and other details kind of ‘cached’ in this list, and there is a timer job that will push changes to the terms out into these lists – and therefore to items that refer to the entries in the list. Continue reading “What happens with a large TaxonomyHiddenList?”
"Minor" Search limitations in Office 365
If you’re a SharePoint developer like me, you probably find the Query Throttle in SharePoint an absolute pain. This is a feature where, under an unnecessarily complicated set of conditions, if you try to ask for too many list items in one query, SharePoint refuses.
Now, while I understand why such a limit is necessary – albeit I’d rather it was simpler – it is something of a problem. For example, multi-choice columns cannot be indexed. If you want to query such a column, and there are more than 5000 items in the list, we’ll, you’re outta luck.
That situation is surprisingly common in Document Management systems. Continue reading “"Minor" Search limitations in Office 365”
Content Approval and Large Lists
So I’ve discovered an interesting problem with Content Approval, which is a special issue for Office 365. I have a document library with more than 5000 documents in it. Content Approval is turned on, and the customer would like a view of ‘Unapproved Documents’.
For a Document Management System, 5000 documents in one repository is small beer, so this is a bit of a problem. “Okay”, I thought, “this must be a choice column, so I’ll just add an index to the column”. Continue reading “Content Approval and Large Lists”
Looking up against Large Lists in Office 365
So, I had an issue that I’ve a customer who wanted to have some items look up against a large list. (In fact, it was a large document library). This large list had more than 5000 items. This is a little unfortunate, due to a painful and annoying quirk in SharePoint’s design. Continue reading “Looking up against Large Lists in Office 365”
Query Throttling in SharePoint 2013
So, last week I was at the #SPEvo13 conference in London, and one innocuous session by Wayne Ewington sent shivers down my spine – about query throttling. So, what is query throttling again, and why did it was I worried? Continue reading “Query Throttling in SharePoint 2013”
Dealing with Large Lists Part 1 – What is throttling and how it causes difficulty
‘Large’ lists – lists with over a few thousand items – can cause problems when you’re developing for SharePoint, and the whole topic is kind of complicated. So what’s the problem?
Well, fundamentally the issue is inefficient queries being run against SharePoint lists. An inefficient query against a list with a small number of items isn’t a big deal, but with larger lists (over 5000 items) SQL server has to escalate from a row-level lock to a table-level lock. This can hold up other users while the table is locked.
So, what are the limits, what options are there with throttling, and what strategies are there for mitigating the effects of query throttling? Continue reading “Dealing with Large Lists Part 1 – What is throttling and how it causes difficulty”
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