Field Type Example title string "Vector DBs 101"tags list[string] ["ml", "db"]score number 0.95published boolean truetimestamp number (unix) 1716067200
Note: Pinecone doesn't enforce a schema. Enforce one in your application layer for filter consistency.
index.upsert( vectors = [{ "id" : "doc1" , "values" : [ ... ], "metadata" : { "source" : "wiki" , "page" : 12 , "tags" : [ "ml" ]}, }])
Example: Partial Update
index.update( id = "doc1" , set_metadata = { "views" : 42 })
Op Effect set_metadataMerge (overwrite per-key) Upsert Full replace
Example: Validation
ALLOWED = ( str , int , float , bool ) def valid (md): for k, v in md.items(): if isinstance (v, list ): if not all ( isinstance (x, str ) for x in v): return False elif not isinstance (v, ALLOWED ): return False return True
Limit Value Per vector 40 KB total List items Counted in total size Nested objects Not supported
Pattern Use Categorical filters category, language, status Temporal filters created_at, expires_at Access control owner_id, visibility Source tracking doc_id, chunk_index
7. Implementing Version Tracking
Example: Version Field
index.upsert( vectors = [{ "id" : "doc1" , "values" : [ ... ], "metadata" : { "version" : 3 , "embedding_model" : "text-embedding-3-small" }, }])
8. Adding Timestamps
Format Recommendation Unix epoch (int) Best for range filters ISO 8601 string Human-readable; no range queries
9. Storing Document References
Example: Doc References
{ "id" : "chunk_abc_3" , "metadata" : { "doc_id" : "abc" , "chunk_index" : 3 , "source_url" : "https://example.com/abc" , "text_snippet" : "..." , }, }
Warning: Nested objects are not supported. Flatten with dot notation or store JSON-as-string (no filtering).
Strategy Example Flatten keys author.name → author_nameStringify JSON raw_json: "{...}" (not filterable)External lookup Store doc ID; fetch full record from DB