Overview
It might be necessary to obtain the per-folder item count from Enterprise Vault prior to migration, for example to be able to compare with the migration target.
Solution
The following SQL query, run over Vault Store, can be used to obtain the per-folder item count:
SELECT b.FolderName, COUNT(*) AS ItemCount FROM [view_Saveset_Archive_Vault] a INNER JOIN [EnterpriseVaultDirectory].[dbo].[ArchiveFolderView] b ON a.VaultID = b.VaultEntryId WHERE a.ArchivePointId = 'xxxxxxxx' GROUP BY b.FolderName