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TN Hist237 Historian 11.X will not read older history blocks

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Historian 11.X will not read older history blocks after being migrated to a new system.


  • Author: Mike Viteri
  • Published: 11/12/2015
  • Applies to: Historian 11.X





After moving older History Blocks into a new Historian 11.X installation. The older History Blocks cannot be accessed for the data. This is because previous versions used the Classic Storage Subsystem. The Storage Subsystem changed in Historian 11.X



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Open your  Microsoft SQL Server Management Studio. Type in the following command in the against the runtime database and execute the query. You should have affected rows.


Update tag set AIHistory = 1 Where AIHistory = 0 and Tagname not like 'sys%'







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Now you will be able to query your older History Blocks for data.