Merge pull request #264809 from AlicjaKucharczyk/patch-4

maintenance_work_mem fix

Author: prmerger-automator[bot]

articles/postgresql/flexible-server/concepts-server-parameters.md

@@ -143,14 +143,19 @@ To find the minimum `work_mem` value for a specific query, especially one genera
 
 | Attribute            |               Value |
 |:---------------------|--------------------:|
-| Default value        |               211MB |
+| Default value        |               Dependent on server memory |
 | Allowed value        |             1MB-2GB |
 | Type                 |             Dynamic |
 | Level         | Global and granular |
 | Azure-Specific Notes |                     |
 
 #### Description
-`maintenance_work_mem` is a configuration parameter in PostgreSQL that governs the amount of memory allocated for maintenance operations, such as `VACUUM`, `CREATE INDEX`, and `ALTER TABLE`. Unlike `work_mem`, which affects memory allocation for query operations, `maintenance_work_mem` is reserved for tasks that maintain and optimize the database structure. Adjusting this parameter appropriately can help enhance the efficiency and speed of database maintenance operations.
+`maintenance_work_mem` is a configuration parameter in PostgreSQL that governs the amount of memory allocated for maintenance operations, such as `VACUUM`, `CREATE INDEX`, and `ALTER TABLE`. Unlike `work_mem`, which affects memory allocation for query operations, `maintenance_work_mem` is reserved for tasks that maintain and optimize the database structure.
+
+#### Key points
+
+* **Vacuum memory cap**: If you intend to speed up the cleanup of dead tuples by increasing `maintenance_work_mem`, be aware that VACUUM has a built-in limitation for collecting dead tuple identifiers, with the ability to use only up to 1GB of memory for this process.
+* **Separation of memory for autovacuum**: The `autovacuum_work_mem` setting allows you to control the memory used by autovacuum operations independently. It acts as a subset of the `maintenance_work_mem`, meaning that you can decide how much memory autovacuum uses without affecting the memory allocation for other maintenance tasks and data definition operations.
 
 
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