---
title: "pg_shmem_allocations"
id: view-pg-shmem-allocations
pg_version: "20devel"
---

<a id="view-pg-shmem-allocations"></a>

## 53.29. pg_shmem_allocations

The pg_shmem_allocations view shows allocations made from the server's main shared memory segment. This includes both memory allocated by PostgreSQL itself and memory allocated by extensions using the mechanisms detailed in [Section 36.10.11](xfunc-c.md#xfunc-shared-addin). 

Note that this view does not include memory allocated using the dynamic shared memory infrastructure. 

**pg_shmem_allocations Columns**

| Column Type | Description | 
| --- | --- |
| `name` `text` | The name of the shared memory allocation. NULL for unused memory and `<anonymous>` for anonymous allocations. |
| `off` `int8` | The offset at which the allocation starts. NULL for anonymous allocations, since details related to them are not known. |
| `size` `int8` | Size of the allocation in bytes |
| `allocated_size` `int8` | Size of the allocation in bytes including padding. For anonymous allocations, no information about padding is available, so the `size` and `allocated_size` columns will always be equal. Padding is not meaningful for free memory, so the columns will be equal in that case also. |

Anonymous allocations are allocations that have been made with `ShmemAlloc()` directly, rather than via `ShmemRequestStruct()` or `ShmemRequestHash()`. 

By default, the pg_shmem_allocations view can be read only by superusers or roles with privileges of the `pg_read_all_stats` role.