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The design of the data structures which allow storage of the per-worker memory during parallel seq scans were not ideal. The work done in 56788d215 required an additional data structure to allow workers to remember the range of pages that had been allocated to them for processing during a parallel seqscan. That commit added a void pointer field to TableScanDescData to allow heapam to store the per-worker allocation information. However putting the field there made very little sense given that we have AM specific structs for that, e.g. HeapScanDescData. Here we remove the void pointer field from TableScanDescData and add a dedicated field for this purpose to HeapScanDescData. Previously we also allocated memory for this parallel per-worker data for all scans, regardless if it was a parallel scan or not. This was just a wasted allocation for non-parallel scans, so here we make the allocation conditional on the scan being parallel. Also, add previously missing pfree() to free the per-worker data in heap_endscan(). Reported-by: Andres Freund Reviewed-by: Andres Freund Discussion: https://postgr.es/m/20210317023101.anvejcfotwka6gaa@alap3.anarazel.de
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/.