  Currently, the in-context learning method based on large language models
(LLMs) has become the mainstream of text-to-SQL research. Previous works have
discussed how to select demonstrations related to the user question from a
human-labeled demonstration pool. However, human labeling suffers from the
limitations of insufficient diversity and high labeling overhead. Therefore, in
this paper, we discuss how to measure and improve the diversity of the
demonstrations for text-to-SQL. We present a metric to measure the diversity of
the demonstrations and analyze the insufficient of the existing labeled data by
experiments. Based on the above discovery, we propose fusing iteratively for
demonstrations (Fused) to build a high-diversity demonstration pool through
human-free multiple-iteration synthesis, improving diversity and lowering label
cost. Our method achieves an average improvement of 3.2% and 5.0% with and
without human labeling on several mainstream datasets, which proves the
effectiveness of Fused.
