from_existing_index

Get instance of an existing Lantern store.This method will return the instance of the store without inserting any new embeddings

Postgres connection string is required "Either pass it as connection_string parameter or set the LANTERN_CONNECTION_STRING environment variable.

• connection_string is a postgres connection string.
• embedding is :class:Embeddings that will be used for embedding the text sent. If none is sent, then the multilingual Tensorflow Universal Sentence Encoder will be used.
• collection_name is the name of the collection to use. (default: langchain)
  • NOTE: This is the name of the table in which embedding data will be stored The table will be created when initializing the store (if not exists) So, make sure the user has the right permissions to create tables.
• ids row ids to insert into collection.
• pre_delete_collection if True, will delete the collection if it exists. (default: False)
  • Useful for testing.
• distance_strategy is the distance strategy to use. (default: EUCLIDEAN)
  • EUCLIDEAN is the euclidean distance.
  • COSINE is the cosine distance.
  • HAMMING is the hamming distance.