When your data has outlived several generations of front-end technologies (mine started with Powerbuilder), you will find that ownership of the data does not co

When your data has outlived several generations of front-end technologies (mine started with Powerbuilder), you will find that ownership of the data does not control the evolution of how it will be used with what replaces past clients. One particularly interesting Oracle problem is: ORA-00060: deadlock detected while waiting for resource Tom Kyte's book, Expert One-on-One Oracle, describes the primary culprit: "Oracle considers deadlocks to be so rare, so unusual, that it creates a trace file on the server each and every time one does occur... The number one cause of deadlocks in the Oracle database, in my experience, is un-indexed foreign keys." For another perspective, add to this a default setting in every SQLite database: $ sqlite3 verynew.db SQLite version 3.34.1 2021-01-20 14:10:07 Enter ".help" for usage hints. sqlite> .dump PRAGMA foreign_keys=OFF; BEGIN TRANSACTION; COMMIT; Foreign keys can cause interesting problems, and SQLite specifically prefers to avoid them.