  Graph representation learning has emerged as a powerful technique for
addressing real-world problems. Various downstream graph learning tasks have
benefited from its recent developments, such as node classification, similarity
search, and graph classification. However, prior arts on graph representation
learning focus on domain specific problems and train a dedicated model for each
graph dataset, which is usually non-transferable to out-of-domain data.
Inspired by the recent advances in pre-training from natural language
processing and computer vision, we design Graph Contrastive Coding (GCC) -- a
self-supervised graph neural network pre-training framework -- to capture the
universal network topological properties across multiple networks. We design
GCC's pre-training task as subgraph instance discrimination in and across
networks and leverage contrastive learning to empower graph neural networks to
learn the intrinsic and transferable structural representations. We conduct
extensive experiments on three graph learning tasks and ten graph datasets. The
results show that GCC pre-trained on a collection of diverse datasets can
achieve competitive or better performance to its task-specific and
trained-from-scratch counterparts. This suggests that the pre-training and
fine-tuning paradigm presents great potential for graph representation
learning.
