Sentence Embedding Optimizer

# My OpenAI Key
import os

os.environ["OPENAI_API_KEY"] = "INSERT OPENAI KEY"

Setup

from llama_index import download_loader

WikipediaReader = download_loader("WikipediaReader")

loader = WikipediaReader()
documents = loader.load_data(pages=["Berlin"])
from llama_index import VectorStoreIndex

index = VectorStoreIndex.from_documents(documents)
<class 'llama_index.readers.schema.base.Document'>
INFO:root:> [build_index_from_documents] Total LLM token usage: 0 tokens
INFO:root:> [build_index_from_documents] Total embedding token usage: 18390 tokens

Compare query with and without optimization for LLM token usage, Embedding Model usage on query, Embedding model usage for optimizer, and total time.

import time
from llama_index import VectorStoreIndex
from llama_index.indices.postprocessor import SentenceEmbeddingOptimizer

print("Without optimization")
start_time = time.time()
query_engine = index.as_query_engine()
res = query_engine.query("What is the population of Berlin?")
end_time = time.time()
print("Total time elapsed: {}".format(end_time - start_time))
print("Answer: {}".format(res))

print("With optimization")
start_time = time.time()
query_engine = index.as_query_engine(
    node_postprocessors=[SentenceEmbeddingOptimizer(percentile_cutoff=0.5)]
)
res = query_engine.query("What is the population of Berlin?")
end_time = time.time()
print("Total time elapsed: {}".format(end_time - start_time))
print("Answer: {}".format(res))

print("Alternate optimization cutoff")
start_time = time.time()
query_engine = index.as_query_engine(
    node_postprocessors=[SentenceEmbeddingOptimizer(threshold_cutoff=0.7)]
)
res = query_engine.query("What is the population of Berlin?")
end_time = time.time()
print("Total time elapsed: {}".format(end_time - start_time))
print("Answer: {}".format(res))
Without optimization
INFO:root:> [query] Total LLM token usage: 3545 tokens
INFO:root:> [query] Total embedding token usage: 7 tokens
Total time elapsed: 2.8928110599517822
Answer: 
The population of Berlin in 1949 was approximately 2.2 million inhabitants. After the fall of the Berlin Wall in 1989, the population of Berlin increased to approximately 3.7 million inhabitants.

With optimization
INFO:root:> [optimize] Total embedding token usage: 7 tokens
INFO:root:> [query] Total LLM token usage: 1779 tokens
INFO:root:> [query] Total embedding token usage: 7 tokens
Total time elapsed: 2.346346139907837
Answer: 
The population of Berlin is around 4.5 million.
Alternate optimization cutoff
INFO:root:> [optimize] Total embedding token usage: 7 tokens
INFO:root:> [query] Total LLM token usage: 3215 tokens
INFO:root:> [query] Total embedding token usage: 7 tokens
Total time elapsed: 2.101111888885498
Answer: 
The population of Berlin is around 4.5 million.