diff --git a/doc/src/sgml/glossary.sgml b/doc/src/sgml/glossary.sgml index 63ff4bbdf0..0c88988fa6 100644 --- a/doc/src/sgml/glossary.sgml +++ b/doc/src/sgml/glossary.sgml @@ -48,7 +48,7 @@ Analyze (operation) - The process of collecting statistics from data in + The act of collecting statistics from data in tables and other relations to help the query planner @@ -113,8 +113,12 @@ A set of background processes that routinely perform vacuum - and analyze - operations. + and analyze operations. + The auxiliary process + that coordinates the work and is always present (unless autovacuum + is disabled) is known as the autovacuum launcher, + and the processes that carry out the tasks are known as the + autovacuum workers. For more information, see @@ -123,6 +127,34 @@ + + Auxiliary process + + + A process within an instance + that is in charge of some specific background task for the instance. + The auxiliary processes consist of + + the autovacuum launcher + (but not the autovacuum workers), + the background writer, + the checkpointer, + the logger, + the startup process, + the statistics collector, + the WAL archiver, + the WAL receiver + (but not the WAL senders), + and the WAL writer. + + + + Backend (process) @@ -163,7 +195,8 @@ Background writer (process) - A process that writes dirty + An auxiliary process + that writes dirty data pages from shared memory to the file system. It wakes up periodically, but works only for a short @@ -285,7 +318,9 @@ Checkpointer (process) - A specialized process responsible for executing checkpoints. + An auxiliary process + that is responsible for executing + checkpoints. @@ -778,8 +813,9 @@ Instance - A group of backend and auxiliary processes that communicate using - a common shared memory area. One + A group of backend and + auxiliary processes + that communicate using a common shared memory area. One postmaster process manages the instance; one instance manages exactly one database cluster @@ -881,8 +917,8 @@ Logger (process) - If activated, the process - writes information about database events into the current + An auxiliary process + which, if enabled, writes information about database events into the current log file. When reaching certain time- or volume-dependent criteria, a new log file is created. @@ -1040,8 +1076,9 @@ The very first process of an instance. - It starts and manages the other auxiliary processes and creates - backend processes + It starts and manages the + auxiliary processes + and creates backend processes on demand. @@ -1452,6 +1489,22 @@ + + Startup process + + + An auxiliary process + that replays WAL during crash recovery and in a + physical replica. + + + (The name is historical: the startup process was named before + replication was implemented; the name refers to its task as it + relates to the server startup following a crash.) + + + + SQL object @@ -1514,8 +1567,10 @@ Stats collector (process) - This process collects statistical information about the - instance's activities. + An auxiliary process + which, if enabled, receives statistical information + about the instance's + activities. For more information, see @@ -1856,7 +1911,9 @@ WAL archiver (process) - A process that saves copies of WAL files + An auxiliary process + which, if enabled, saves copies of + WAL files for the purpose of creating backups or keeping replicas current. @@ -1914,11 +1971,44 @@ + + WAL receiver + + + An auxiliary process + that runs on a replica + to receive WAL from the + primary server + for replay by the + startup process. + + + + For more information, see + . + + + + WAL segment + + WAL sender (process) + + + A special backend process + that streams WAL over a network. The receiving end can be a + WAL receiver + in a replica, + , or any other client program + that speaks the replication protocol. + + + + WAL writer (process) diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h index 2e2e9a364a..90a3016065 100644 --- a/src/include/miscadmin.h +++ b/src/include/miscadmin.h @@ -422,6 +422,8 @@ extern ProcessingMode Mode; * Auxiliary-process type identifiers. These used to be in bootstrap.h * but it seems saner to have them here, with the ProcessingMode stuff. * The MyAuxProcType global is defined and set in auxprocess.c. + * + * Make sure to list in the glossary any items you add here. */ typedef enum