
This function reads directly a page from a relation, relying on index_open() to open the index to read from. Unfortunately, this would crash when using partitioned indexes, as these can be opened with index_open() but they have no physical pages. Alexander has fixed the module, while I have written the test. Author: Alexander Lakhin, Michael Paquier Discussion: https://postgr.es/m/18246-f4d9ff7cb3af77e6@postgresql.org Backpatch-through: 12