---
title: "Hierarchical / Paging (core vs archival) · agent retrieval pattern · Agent Fieldbook"
url: https://agentfieldbook.org/memory/retrieval/hierarchical-paging/
description: "Tiered memory, in-context core vs external archival, with data moved between tiers on demand."
section: "Memory · Retrieval"
source: Agent Fieldbook — generated from the published page
---

# Hierarchical / Paging (core vs archival)

Tiered memory, in-context core vs external archival, with data moved between tiers on demand.

Verified against [arxiv.org](https://arxiv.org/abs/2310.08560)

- [arxiv.org](https://arxiv.org/abs/2310.08560)

## How it works

## At a glance

| Field | Value |
| --- | --- |
| Stage | Retrieval |
| Phase | Both |
| Used by | MemGPT· Letta (core / archival memory tiers) |

## Trade-off

Paging and tier-eviction policy add complexity and can evict still-needed data.

## Basis

## Verified against

- [https://arxiv.org/abs/2310.08560](https://arxiv.org/abs/2310.08560)

The corpus does not rewrite vendor documentation. Where copy is quoted verbatim it is marked as such and attributed to its source.