f92c854cf4
Currently in pg_stat_io view, IOs are counted as blocks of size BLCKSZ. There are two limitations with this design: * The actual number of I/O requests sent to the kernel is lower because I/O requests may be merged before being sent. Additionally, it gives the impression that all I/Os are done in block size, which shadows the benefits of merging I/O requests. * Some patches are under work to extend pg_stat_io for the tracking of operations that may not be linked to the block size. For example, WAL read IOs are done in variable bytes and it is not possible to correctly show these IOs in pg_stat_io view, and we want to keep all this data in a single system view rather than spread it across multiple relations to ease monitoring. WaitReadBuffers() can now be tracked as a single read operation worth N blocks. Same for ExtendBufferedRelShared() and ExtendBufferedRelLocal() for extensions. Three columns are added to pg_stat_io for reads, writes and extensions for the byte calculations. op_bytes, which was always hardcoded to BLCKSZ, is removed. IO backend statistics are updated to reflect these changes. Bump catalog version. Author: Nazir Bilal Yavuz Reviewed-by: Bertrand Drouvot, Melanie Plageman Discussion: https://postgr.es/m/CAN55FZ0oqxBaaHAEsj=xFqkzE3n5P=3RA1V_igXwL-RV7QRzyw@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/.