One of our clients has real-world cases that run slowly if OP_SeekScan is turned off. In fact, OP_SeekScan was added specifically to support that client. We have cases in the TH3 test suite that run more slowly when OP_SeekScan is disabled. If you don't want to ever use OP_SeekScan, you can now disable it at run-time using the [SQLITE_TESTCTRL_OPTIMIZATIONS][2] [test-control][1] with a mask of 0x20000: > sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS, db, 0x20000); In the CLI use this dot-command: > .testctrl optimizations 0x20000 If you discover a test case that runs faster with OP_SeekScan disabled, please bring it to our attention by posting it on this forum. [1]: https://www.sqlite.org/c3ref/test_control.html [2]: https://www.sqlite.org/c3ref/c_testctrl_always.html