[tanjiroK-coder]

Select.appendStringListTo builds a comma-separated list by reading its argument positionally with list.get(i). Join stores its USING columns in a LinkedList, so deparsing SELECT ... JOIN ... USING (c0, ..., cN) through Join.toString is O(N^2), and the USING column list has no bound in the grammar. Parsing a 200k-column clause and then calling Statement.toString does not finish within 5 s here, against about 55 ms after the change, and the parser timeout does not cover deparsing. ConnectExpressionsVisitor has the same shape: it connects the select items it collected into a LinkedList by indexing them with get(i) in a loop, so joining a select with many items is quadratic too. Both now walk the list once with an iterator instead of by index; the deparsed text and the built expression tree are unchanged. I added regression tests over 200k elements under a 5 s preemptive timeout, which hang before the change and pass after.

[manticore-projects]

Thank you!