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We've been nibbling away at removing uses of "long" for a long time, since its width is platform-dependent. Here's one more: change the remaining "long" fields in Plan nodes to Cardinality, since the three surviving examples all represent group-count estimates. The upstream planner code was converted to Cardinality some time ago; for example the corresponding fields in Path nodes are type Cardinality, as are the arguments of the make_foo_path functions. Downstream in the executor, it turns out that these all feed to the table-size argument of BuildTupleHashTable. Change that to "double" as well, and fix it so that it safely clamps out-of-range values to the uint32 limit of simplehash.h, as was not being done before. Essentially, this is removing all the artificial datatype-dependent limitations on these values from upstream processing, and applying just one clamp at the moment where we're forced to do so by the datatype choices of simplehash.h. Also, remove BuildTupleHashTable's misguided attempt to enforce work_mem/hash_mem_limit. It doesn't have enough information (particularly not the expected tuple width) to do that accurately, and it has no real business second-guessing the caller's choice. For all these plan types, it's really the planner's responsibility to not choose a hashed implementation if the hashtable is expected to exceed hash_mem_limit. The previous patch improved the accuracy of those estimates, and even if BuildTupleHashTable had more information it should arrive at the same conclusions. Reported-by: Jeff Janes <jeff.janes@gmail.com> Author: Tom Lane <tgl@sss.pgh.pa.us> Reviewed-by: David Rowley <dgrowleyml@gmail.com> Discussion: https://postgr.es/m/CAMkU=1zia0JfW_QR8L5xA2vpa0oqVuiapm78h=WpNsHH13_9uw@mail.gmail.com
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/devel/. In particular, information about building PostgreSQL from the source code can be found at https://www.postgresql.org/docs/devel/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/.