Hi all,
Apologies in advance for the longer e-mail! I am a grad student adapting
Calcite for use in a research project prototype. The functionality I am
trying to add involves inserting non-executable operators into a plan to
represent abstract sets of queries.
For example, it takes two queries like,
"select a from t"
and
"select b from t"
and combines them into:
"select any {a, b} from t".
Similarly, an "any{}" operator can have, e.g. a list of filtering
conditions and other grammatical options. These queries are not intended to
ever be executed and only exist for us to write planning rules over!
I am able to parse statements like the one above, but I am having a great
bit of trouble trying to validate and convert to a relational expression.
The output of the convertSqlToRel test I added is:
LogicalProject(EXPR$0=[ANY($1)])
LogicalTableScan(table=[(t1, t2, t3)])
I created a SqlNode named SqlAny and a RexNode RexAny that is parsed
correctly, but after validation it is converted to a SqlBasicCall. I am
able to catch it by examining the operator type in
convertExtendedExpression() and return a RexAny node, but I am not sure
what to add to the validator to avoid this hack and preserve the
fieldnames that are operands to SqlAny.
Please, any and all help is appreciated!
Cheers,
Lana
