How do you handle timestamp/versioning to detect stale data in the IndexedDB cache?

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ICSM Computer · Answer

To detect stale data in IndexedDB during synchronization with a remote server, the most common and reliable technique is to use timestamps or versioning metadata on each record. Here’s how to handle it effectively: 1. Add a lastModified or version Field per Record Every record stored in IndexedDB and on the server should include one of: lastModified: A UTC timestamp (e.g., ISO 8601 or Unix Epoch).version: A monotonically increasing number (e.g., int or UUID/ETag). Example Record: 2. Compare Timestamps during Sync During sync: Fetch latest server records (with their lastModified or version).Compare with the corresponding IndexedDB record.If the local version is older, update from the server.If the local version is newer, push to server.If both changed, trigger conflict resolution. Example (timestamp comparison): 3. Batch Versioning for Sync Tokens If you want to track updates more efficiently: Maintain a global lastSyncTimestamp.During sync, fetch records from the server with lastModified &gt; lastSyncTimestamp.Apply changes and update local IndexedDB.Then update lastSyncTimestamp. 4. Handle Clock Skew (if using timestamps) Rely on server-generated timestamps whenever possible.On client-side creation, mark them as “pending” until server confirmation. 5. Optional: Use Hashing for Change Detection For large documents: Generate a hash (e.g., SHA-256) of the content.Store this alongside the record and compare it during sync.More accurate than timestamps alone. Dexie.js Example Summary Field Purpose Format lastModified Detect stale updates ISO Date or Unix Timestamp version Optional alternative to timestamps Integer or UUID syncStatus Optional (e.g., pending, synced, conflict) String

How do you handle timestamp/versioning to detect stale data in the IndexedDB cache?

1 Answers

1. Add a `lastModified` or `version` Field per Record

Example Record:

2. Compare Timestamps during Sync

Example (timestamp comparison):

3. Batch Versioning for Sync Tokens

4. Handle Clock Skew (if using timestamps)

5. Optional: Use Hashing for Change Detection

Dexie.js Example

Summary

Field	Purpose	Format
`lastModified`	Detect stale updates	ISO Date or Unix Timestamp
`version`	Optional alternative to timestamps	Integer or UUID
`syncStatus`	Optional (e.g., `pending`, `synced`, `conflict`)	String

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How do you handle timestamp/versioning to detect stale data in the IndexedDB cache?

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1 Answers

1. Add a lastModified or version Field per Record

Example Record:

2. Compare Timestamps during Sync

Example (timestamp comparison):

3. Batch Versioning for Sync Tokens

4. Handle Clock Skew (if using timestamps)

5. Optional: Use Hashing for Change Detection

Dexie.js Example

Summary

1. Add a `lastModified` or `version` Field per Record