4feba03d8b
9aea73fc61 has added support for backend statistics, relying on
PgStat_EntryRef->pending for its data pending for flush. This design
lacks in flexibility, because the pending list does some memory
allocation, making it unsuitable if incrementing counters in critical
sections.
Pending data of backend statistics is reworked so the implementation
does not depend on PgStat_EntryRef->pending anymore, relying on a static
area of memory to store the counters that are flushed when stats are
reported to the pgstats dshash. An advantage of this approach is to
allow the pending data to be manipulated in critical sections; some
patches are under discussion and require that.
The pending data is tracked by PendingBackendStats, local to
pgstat_backend.c. Two routines are introduced to allow IO statistics to
update the backend-side counters. have_static_pending_cb and
flush_static_cb are used for the flush, instead of flush_pending_cb.
Author: Bertrand Drouvot, Michael Paquier
Discussion: https://postgr.es/m/66efowskppsns35v5u2m7k4sdnl7yoz5bo64tdjwq7r5lhplrz@y7dme5xwh2r5PostgreSQL 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.
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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.
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