The patch applied successfully, and the build completed without issues. I verified that brin_index_check() is not available on an unpatched build,and after applying the patch and updating the amcheck extension to version 1.6 ,the function worked as expected. I also ran some basic BRIN index validation tests successfully. One small thing I noticed during testing :after installing the patched build,I needed to run ALTER EXTENSION amcheck UPDATE before brin_index_check() became available.
Regards, Solai
