2fa989e6a3
Avoid issuing a separate SQL UPDATE command for each column when directly manipulating pg_attribute contents in binary upgrade mode. With the separate updates, we triggered a relcache invalidation with each update. For a table with N columns, that causes O(N^2) relcache bloat in txn_size mode because the table's newly-created relcache entry can't be flushed till end of transaction. Reducing the number of commands should make it marginally faster as well as avoiding that problem. While at it, likewise avoid issuing a separate UPDATE on pg_constraint for each inherited constraint. This is less exciting, first because inherited (non-partitioned) constraints are relatively rare, and second because the backend has a good deal of trouble anyway with restoring tables containing many such constraints, due to MergeConstraintsIntoExisting being horribly inefficient. But it seems more consistent to do it this way here too, and it surely can't hurt. In passing, fix one place in dumpTableSchema that failed to use ONLY in ALTER TABLE. That's not a live bug, but it's inconsistent. Also avoid silently casting away const from string literals. Per report from Justin Pryzby. Back-patch to v17 where txn_size mode was introduced. Discussion: https://postgr.es/m/ZqEND4ZcTDBmcv31@pryzbyj2023
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.
Copyright and license information can be found in the file COPYRIGHT.
General documentation about this version of PostgreSQL can be found at https://www.postgresql.org/docs/17/. In particular, information about building PostgreSQL from the source code can be found at https://www.postgresql.org/docs/17/installation.html.
The latest version of this software, and related software, may be obtained at https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.