In computing, a persistent data structure or not ephemeral data structure is a data structure that always preserves the previous version of itself when it is modified.

2024年2月28日 · A persistent data structure is a data structure that always preserves the previous version of itself when it is modified. They can be considered as ‘immutable’ as updates are not in-place. A data structure is partially persistent if all versions can be accessed but only the newest version can be modified.

The first lecture covers persistent data structures. First we introduce the pointer machine model, and four levels of persistencies: partial, full, confluent, and functional.

Persistence in the context of data structures refers to the ability to retain the previous versions of a data structure while modifying it. In other words, persistent data structures allow for the efficient storage and retrieval of both past and current versions of the data.

Description: “Persistence”–remembering all past versions of a data structure (“partial persistence”), being able to modify them—forking off new ones (“full persistence”), and merging different versions into one (“confluent persistence”).

2024年8月24日 · Persistent data structures are a crucial tool for any developer working with large amounts of data. By understanding the key concepts and mechanisms that underlie their functionality, developers can create efficient and reliable data structures that meet the demands of modern applications.

Our goal: use simulation to transform any ephemeral data structure into a persistent one. measure of success: time and space cost for each primitive traversal and primitive modification step. We’ll limit to trees. Key principles: analysis via potential function measuring “complexity” of structure.

Persistent Data Structures preserve previous versions of themselves allowing us to revisit and audit any historical version. Depending on the operations allowed on the previous versions, persistence is classified into three categories.

Persistent data structures are really data structures with archaeology. Partial persistence lets you make modifications only to the present data structure but allows queries of any previous version. These previous versions might be accessed via a timestamp.

A persistent data structure is a data structure that always preserves the previous version of itself when it is modified. In more detail, persistent data structures are a key concept in computer science, particularly in functional programming and certain database systems.