Performance impacts while Indexing a SharePoint list in production environment

Question

Indexing a column in a SharePoint list that's approaching the 5000 items threshold limit.

Are there any expected impacts for users/apps consuming/writing to that list during index creation? Should I schedule an 'outage' to do this? When will I know the index has been created?

Column to be indexed: Created (Date and time field).

Answer 1

Consider the below points before you start indexing your List/Library

1. Creating an index requires accessing all items in the list
2. Each column being indexed consumes extra resources in the database and adds some overhead to every operation to maintain the index.
3. If your list item count exceeds the List View Threshold or the item count is in millions, its better to do the operation during the scheduled time window as it might take time to set index for the column by fetching all items.
4. But mostly, while Indexing a column wont affect any other operations. We have did it many times in Production site already in a support project.