Method evalEncodings

bolt/expression/Expr.cpp:1064–1117

}

void Expr::evalEncodings(
    const SelectivityVector& rows,
    EvalCtx& context,
    VectorPtr& result) {
  if (deterministic_ && !skipFieldDependentOptimizations()) {
    bool hasFlat = false;
    for (auto* field : distinctFields_) {
      if (isFlat(*context.getField(field->index(context)))) {
        hasFlat = true;
        break;
      }
    }

    if (!hasFlat) {
      VectorPtr wrappedResult;
      // Attempt peeling and bound the scope of the context used for it.

      withContextSaver([&](ContextSaver& saveContext) {
        LocalSelectivityVector newRowsHolder(context);
        LocalSelectivityVector finalRowsHolder(context);
        LocalDecodedVector decodedHolder(context);
        auto peelEncodingsResult = peelEncodings(
            context,
            saveContext,
            rows,
            decodedHolder,
            newRowsHolder,
            finalRowsHolder);
        auto* newRows = peelEncodingsResult.newRows;
        if (newRows) {
          VectorPtr peeledResult;
          // peelEncodings() can potentially produce an empty selectivity
          // vector if all selected values we are waiting for are nulls. So,
          // here we check for such a case.
          if (newRows->hasSelections()) {
            if (peelEncodingsResult.mayCache) {
              evalWithMemo(*newRows, context, peeledResult);
            } else {
              evalWithNulls(*newRows, context, peeledResult);
            }
          }
          wrappedResult = context.getPeeledEncoding()->wrap(
              this->type(), context.pool(), peeledResult, rows);
        }
      });

      if (wrappedResult != nullptr) {
        context.moveOrCopyResult(wrappedResult, rows, result);
        return;
      }
    }
  }
  evalWithNulls(rows, context, result);
}

bool Expr::removeSureNulls(
    const SelectivityVector& rows,