ENABLE_EXPR_REWRITES Query Option
The ENABLE_EXPR_REWRITES query option controls whether to enable or disable the query compile time optimizations. These optimizations rewrite the expression trees to a more compact and optimized form that helps avoid redundant expression evaluation at run time. Performance optimizations controlled by this query option include:
- Constant folding (added in )
- Extracting common conjuncts from disjunctions (added in )
- Simplify conditionals with constant conditions (added in )
Set the option to false or 0 to disable the performance optimizations.
Default: true (1)
Added in: CDH 5.10