Mini-Batch Consistent Slot Set Encoder for Scalable Set Encoding

Most existing set encoding algorithms operate under the assumption that all the elements of the set are accessible during training and inference. Additionally, it is assumed that there are enough computational resources available for concurrently processing sets of large cardinality. However, both assumptions fail when the cardinality of the set is prohibitively large such that we cannot even load the set into memory. In more extreme cases, the set size could be potentially unlimited, and the elements of the set could be given in a streaming manner, where the model receives subsets of the full set data at irregular intervals. To tackle such practical challenges in large-scale set encoding, we go beyond the usual constraints of invariance and equivariance and introduce a new property termed Mini-Batch Consistency that is required for large scale mini-batch set encoding. We present a scalable and efficient set encoding mechanism that is amenable to mini-batch processing with respect to set elements and capable of updating set representations as more data arrives. The proposed method respects the required symmetries of invariance and equivariance as well as being Mini-Batch Consistent for random partitions of the input set. We perform extensive experiments and show that our method is computationally efficient and results in rich set encoding representations for set-structured data.