Count rows within partition in Azure table storage

As you may already know that there's no Count like functionality available in Azure Tables. In order to get the total number of entities (rows) in a Partition (or a Table), you have to fetch all entities.

You can reduce the response payload by using a technique called Query Projection. A query projection allows you to specify the list of entity attributes (columns) that you want table service to return. Since you're only interested in total count of entities, I would recommend that you only fetch PartitionKey back. You may find this blog post helpful for understanding about Query Projection: https://blogs.msdn.microsoft.com/windowsazurestorage/2011/09/15/windows-azure-tables-introducing-upsert-and-query-projection/.

https://azure.microsoft.com/en-gb/features/storage-explorer/ allows you to define a Query and you can use the Table Statistics toolbar item to get the total rows for the whole table or your query