Prior to the implementation of feature 28471
in version 7.1.3, PWODecisionRuleRulerDetect
table functions were created as multi-statement table-valued functions, but only ever returned one statement's result set with it. In such instances an inline table-valued function is more favourable because it allows for SQL server to include table statistics. SQL Server can then use an optimized execution plan. An example for a discussion around this can be found here: Comparing Inline and Multi-Statement Table-Valued Functions
However, in some instances, when customer statements for ruler detection were not performing well, the optimized execution plans from the inline table-valued functions performed worse than the non-optimized execution plans for the multi-statement table-valued functions.
A common example for such statements is when customers used a comparison of UID values, which are Varchar columns since version 7.0, against NVarchar strings. This could be a leftover of statements that customers configured in version 6.1 or earlier.