04e72ed617
Commit 7c70996ebf0949b142 introduced an optimization to allow bitmap scans to operate like index-only scans by not fetching a block from the heap if none of the underlying data is needed and the block is marked all visible in the visibility map. With the introduction of table AMs, a FIXME was added to this code indicating that the skip_fetch logic should be pushed into the table AM-specific code, as not all table AMs may use a visibility map in the same way. This commit resolves this FIXME for the current block. The layering violation is still present in BitmapHeapScans's prefetching code, which uses the visibility map to decide whether or not to prefetch a block. However, this can be addressed independently. Author: Melanie Plageman Reviewed-by: Andres Freund, Heikki Linnakangas, Tomas Vondra, Mark Dilger Discussion: https://postgr.es/m/CAAKRu_ZwCwWFeL_H3ia26bP2e7HiKLWt0ZmGXPVwPO6uXq0vaA%40mail.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/.