9aea73fc61
This adds a new variable-numbered statistics kind in pgstats, where the object ID key of the stats entries is based on the proc number of the backends. This acts as an upper-bound for the number of stats entries that can exist at once. The entries are created when a backend starts after authentication succeeds, and are removed when the backend exits, making the stats entry exist for as long as their backend is up and running. These are not written to the pgstats file at shutdown (note that write_to_file is disabled, as a safety measure). Currently, these stats include only information about the I/O generated by a backend, using the same layer as pg_stat_io, except that it is now possible to know how much activity is happening in each backend rather than an overall aggregate of all the activity. A function called pg_stat_get_backend_io() is added to access this data depending on the PID of a backend. The existing structure could be expanded in the future to add more information about other statistics related to backends, depending on requirements or ideas. Auxiliary processes are not included in this set of statistics. These are less interesting to have than normal backends as they have dedicated entries in pg_stat_io, and stats kinds of their own. This commit includes also pg_stat_reset_backend_stats(), function able to reset all the stats associated to a single backend. Bump catalog version and PGSTAT_FILE_FORMAT_ID. Author: Bertrand Drouvot Reviewed-by: Álvaro Herrera, Kyotaro Horiguchi, Michael Paquier, Nazir Bilal Yavuz Discussion: https://postgr.es/m/ZtXR+CtkEVVE/LHF@ip-10-97-1-34.eu-west-3.compute.internal
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/.