This LNCS conference volume constitutes the proceedings of 29th International Symposium on Database Engineered Applications, IDEAS 2025, in Newcastle upon Tyne, UK, in July 2025.

The 13 full papers and 6 short papers included in this book were carefully reviewed and selected from 30 submissions. They were organized in topical sections as follows: language and models; classification; distributed systems; query answering and education; and data mining.