Problem: Large Feature Class attribute tables are slow to open
It takes a long time to open an Attribute Table of a Feature Class stored in ArcSDE using ArcMap.
If the Feature Class is not registered with the ArcSDE, then the SQL sent to the database contains an outer join to return records that are in the business table, but have NULL shapes. The outer join causes a full table scan of the business table.
Solution or Workaround
Register the Feature Class with the Geodatabase using ArcCatalog. This adds an objectid field used in the query, instead of the outer join.
To Register a Feature Class with the Geodatabase, refer to the ArcGIS Help topic: "Registering SDE layers and tables with the geodatabase".