@Override
  public void txRemoveOldIndexEntry(Operation op, RegionEntry entry) {
    if ((op.isUpdate() && !entry.isInvalid()) || op.isInvalidate() || op.isDestroy()) {
      IndexManager idxManager = _getOwner().getIndexManager();
      if (idxManager != null) {
        try {
          idxManager.updateIndexes(entry, IndexManager.REMOVE_ENTRY,
              op.isUpdate() ? IndexProtocol.BEFORE_UPDATE_OP : IndexProtocol.OTHER_OP);
        } catch (QueryException e) {
          throw new IndexMaintenanceException(e);
        }
      }
    }
  }
Removing the existing indexed value requires the current value in the cache, that is the one
prior to applying the operation.

@param entry the RegionEntry that contains the value prior to applying the op
geode-core/src/main/java/org/apache/geode/internal/cache/AbstractRegionMap.java