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Generally, if the comparison operators for a datatype or pair of datatypes are leakproof, the corresponding btree comparison support function can be considered so as well. But we had not originally worried about marking support functions as leakproof, reasoning that they'd not likely be used in queries so the marking wouldn't matter. It turns out there's at least one place where it does matter: calc_arraycontsel() finds the target datatype's default btree comparison function and tries to use that to estimate selectivity, but it will be blocked in some cases if the function isn't leakproof. This leads to unnecessarily poor selectivity estimates and bad plans, as seen in bug #15251. Hence, run around and apply proleakproof markings where the corresponding btree comparison operators are leakproof. (I did eyeball each function to verify that it wasn't doing anything surprising, too.) This isn't a full solution to bug #15251, and it's not back-patchable because of the need for a catversion bump. A more useful response probably is to consider whether we can check permissions on the parent table instead of the child. However, this change will help in some cases where that won't, and it's easy enough to do in HEAD, so let's do so. Discussion: https://postgr.es/m/3876.1531261875@sss.pgh.pa.us
PostgreSQL Database Management System ===================================== This directory contains the source code distribution of the PostgreSQL database management system. PostgreSQL is an advanced object-relational database management system that supports an extended subset of the SQL standard, including transactions, foreign keys, subqueries, triggers, user-defined types and functions. This distribution also contains C language bindings. PostgreSQL has many language interfaces, many of which are listed here: https://www.postgresql.org/download See the file INSTALL for instructions on how to build and install PostgreSQL. That file also lists supported operating systems and hardware platforms and contains information regarding any other software packages that are required to build or run the PostgreSQL system. Copyright and license information can be found in the file COPYRIGHT. A comprehensive documentation set is included in this distribution; it can be read as described in the installation instructions. The latest version of this software may be obtained at https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.