Improve attribute query performance over a feature class by defining a flattened view for that feature class.
Slow query performance.
If the G/Technology data server internally identifies that there is a flattened view defined for a feature class, attribute queries are run over Oracle first using a live ADO connection, and the data server internally gets several key fields (G3E_ID, G3E_FID, and G3E_CID) information along with additional fields defined over that flattened view. Using the data of these key fields, the data server internally picks up graphics information from the DDC file and serves the final filtered data to the client.
However, you must organize the query statement in such a way that minimal records are fetched from the Oracle warehouse over the network; otherwise, it may also degrade the performance.