[ASTERIXDB-2441][COMP] Improve column alias handling in ORDERBY/LIMIT - user model changes: no - storage format changes: no - interface changes: no
Details: - Introduce LET clauses for column alias expressions instead of inlining them into ORDER BY/LIMIT clauses - Fix incorrect visitor used in SubstituteGroupbyExpressionWithVariableVisitor for rewriting LET clauses after GROUP BY
[ASTERIXDB-2394][COMP] Align VarCounter in query rewritting - user model changes: no - storage format changes: no - interface changes: no
Details: Currently, before we do certain language rewritings, we take a snapshot of the var counter in the context and pass it to the rewriter. This works fine in most of the cases, but it can fail when the rewriter introduces new variables. This will cause different variables map to the same variable id. Although this error may be fixed by another ScopingVisitor, the compiler could fail if there is no more visitor down in the rewriting workflow.