A Comprehensive Exploration on WikiSQL with Table-Aware Word Contextualization

WikiSQL is the task of mapping a natural language question to a SQL query given a table from a Wikipedia article. We first show that learning highly context- and table-aware word representations is arguably the most important consideration for achieving a high accuracy in the task. We explore three variants of BERT-based architecture and our best model outperforms the previous state of the art by 8.2% and 2.5% in logical form and execution accuracy, respectively. We provide a detailed analysis of the models to guide how word contextualization can be utilized in a such semantic parsing task. We then argue that this score is near the upper bound in WikiSQL, where we observe that the most of the evaluation errors are due to wrong annotations. We also measure human accuracy on a portion of the dataset and show that our model exceeds the human performance, at least by 1.4% execution accuracy.