There are multiple scenarios where copying only incremental changes from the source environment to the target are preferable to create a full copy of all content.
Migrator supports incremental copying of content into both libraries and lists but there are several key differences when using the Incremental Copy feature (Advanced Options).
NOTE: The use of Incremental Copy has a significant impact on performance and it is recommended that users apply a filter (e.g. modified at, property is greater than migration date) to reduce the duration of this operation.
Libraries implement incremental copies using the file names. When the Incremental Copy option is selected any duplicate items on the target will be replaced with the source item.
Lists (unlike Libraries) implement incremental copies through an internal attribute (item id). This attribute is automatically generated and sequenced by SharePoint and cannot be overwritten. Therefore, a different approach is used to identify new and updated items, but the result is the same as for Libraries. Any duplicate items will be replaced with the source item.
The Incremental copy option has a filter that allows for the determination of the number and age of the changes that will be brought over during the incremental copy. By selecting the number of days, weeks, or months, you can choose to only bring over differences from the last full copy that was made in the determined time.
Delta Migration - If selecting "0" as the value for the incremental filter, the tool will do a content analysis of both source and target and bring over any content that is identified as differential. In the case of this migration, if a file exists on the source that is not on the target, said file will be copied to the target. In the event that the item exists in the target, the tool will check to see if the item on the source is newer than the one on the target (based off of the last modified date). If the item on the source is newer, then the item will be copied from the source to the target.
·This operation is extremely time, processor, and memory intensive as it has to scan every item on both your source and target environments. We only recommend using the "0" delta migration in cases where it is absolutely necessary. Otherwise, set a filter which will specify a time period for the comparison.
·Due to their inherit complexity, Wiki Page libraries and Discussion lists will not be processed during incremental or delta migrations.