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http://msdn.microsoft.com/en-us/libr...34(AX.10).aspx
Adjust the use of autogenerated string functions
Microsoft Dynamics AX embeds some string functions in SELECT statements automatically. String functions are included to support:
Treating uppercase and lowercase versions of the same text as the same text (single case) for Oracle installations.
Left justification or right justification.
When a string function is included in a query, the optimizer may have to choose a less-than-optimal access plan, such as a table scan, for retrieving data. If customers do not require the use of mixed case outside Microsoft Dynamics AX and do not use left justification or right justification, these functions are not required and should be turned off. To improve performance, we recommend that all values be stored left-aligned by default.
If queries take longer to run than anticipated or appear to be using table scans rather than indexes, try the following adjustments:
Clear Include LTRIM in all SELECT statements to remove leading space from right-aligned columns.
Clear Include SUBSTR and LOWER in all SELECT statements to support Oracle mixed-case systems.
If the adjustment is successful, queries use query plans and return results more quickly.