With Microsoft Dynamics Nav, it is possible to add a “FlowField” to a table. This flow field is then calculates an aggregate of an underlying table.

Typical uses are to perform the following calculations:

• Sum
• Average
• Min
• Max
• Count

Additionally, the following non-aggregate functions are available:

• Lookup
• Exists

Typical values which can be calculated via flow fields include:

• Inventory
• Quantity on Sales Order
• Quantity on Purchase Order

With some versions of Microsoft Dynamics Nav, opening a page can be extremely slow. If you compare it to an earlier version, say 2009 or 2013, the speed of the earlier version can be a lot quicker.

This is due to the FlowFields on the page. With some versions of Nav, the FlowFields are calculated when you open the page, which can be quite time consuming, especially where there are lots of records. Even if the FlowField is not visible on the page! On earlier versions of Nav, if you hide the field, the FlowField is not calculated, so the issue is not present.

Therefore if you have a page with a flowfield which is not used, instead of hiding it from the page, delete it completely.

Further information of this issue is available here on the Mibuso forum.