57d11ef028
Check the remote relkind before trying to use TABLESAMPLE to acquire sample from the remote relation. Even if the remote server version has TABLESAMPLE support, the foreign table may point to incompatible relkind (e.g. a view or a sequence). If the relkind does not support TABLESAMPLE, error out if TABLESAMPLE was requested specifically (as system/bernoulli), or fallback to random just like we do for old server versions. We currently end up disabling sampling for such relkind values anyway, due to reltuples being -1 or 1, but that seems rather accidental, and might get broken by improving reltuples estimates, etc. So better to make the check explicit. Reported-by: Tom Lane Discussion: https://postgr.es/m/951485.1672461744%40sss.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/.