/** @return Nodes to execute on. */
  private Collection<ClusterNode> nodes() {
    CacheMode cacheMode = cctx.config().getCacheMode();

    switch (cacheMode) {
      case LOCAL:
        if (prj != null)
          U.warn(
              log,
              "Ignoring query projection because it's executed over LOCAL cache "
                  + "(only local node will be queried): "
                  + this);

        return Collections.singletonList(cctx.localNode());

      case REPLICATED:
        if (prj != null || partition() != null) return nodes(cctx, prj, partition());

        return cctx.affinityNode()
            ? Collections.singletonList(cctx.localNode())
            : Collections.singletonList(F.rand(nodes(cctx, null, partition())));

      case PARTITIONED:
        return nodes(cctx, prj, partition());

      default:
        throw new IllegalStateException("Unknown cache distribution mode: " + cacheMode);
    }
  }
 /** @throws IgniteCheckedException If query is invalid. */
 public void validate() throws IgniteCheckedException {
   if ((type != SCAN && type != SET) && !GridQueryProcessor.isEnabled(cctx.config()))
     throw new IgniteCheckedException("Indexing is disabled for cache: " + cctx.cache().name());
 }