## Issue
- Explicit filtering was being done after search by the bi-encoder
but before re-ranking by the cross-encoder
- This limited the quality of results being returned for queries with explicit filters.
The bi-encoder returned results which were going to be excluded.
So the burden of improving those limited results post filtering was on the
cross-encoder, by re-ranking the remaining results to best match the query
## Fix
- Given that the entry and its embedding are at the same index in their respective lists.
We know which entries map to which embedding tensors.
So we can run the filter for blocked, required words before the bi-encoder search.
And limit entries, embeddings being considered for the current query
## Result
- Semantic search by the bi-encoder returns the most relevant results
for the query, knowing that the results aren't going to be filtered out after.
So the cross-encoder shoulders less of the burden of improving the results
## Corollary
- This pre-filtering technique allows us to apply other explicit filters
on entries relevant for the current query, before calling search
- E.g limit search to entries within date/time specified in query
Semantic Search
Allow natural language search on user content like notes, images, transactions using transformer ML models
User can interface with semantic-search via the API or Emacs. All search is done locally*
Demo
Setup
1. Clone
git clone https://github.com/debanjum/semantic-search && cd semantic-search
2. Configure
- [Required] Update docker-compose.yml to mount your images, org-mode notes and beancount directories
- [Optional] Edit application configuration in sample_config.yml
3. Run
docker-compose up -d
Note: The first run will take time. Let it run, it's mostly not hung, just generating embeddings
Use
-
Semantic Search via API
-
Semantic Search via Emacs
- Install semantic-search.el
- Run
M-x semantic-search <user-query>
Run Unit tests
pytest
Upgrade
docker-compose build --pull
Troubleshooting
-
Symptom: Errors out with "Killed" in error message
- Fix: Increase RAM available to Docker Containers in Docker Settings
- Refer: StackOverflow Solution, Configure Resources on Docker for Mac
-
Symptom: Errors out complaining about Tensors mismatch, null etc
- Mitigation: Delete content-type > image section from docker_sample_config.yml
Miscellaneous
-
The experimental chat API endpoint uses the OpenAI API
- It is disabled by default
- To use it add your
openai-api-keyto config.yml
Development Setup
Setup on Local Machine
1. Install Dependencies
- Install Python3 [Required]
- Install Conda [Required]
-
Install Exiftool [Optional]
sudo apt-get -y install libimage-exiftool-perl
2. Install Semantic Search
git clone https://github.com/debanjum/semantic-search && cd semantic-search
conda env create -f config/environment.yml
conda activate semantic-search
3. Configure
- Configure files/directories to search in
content-typesection ofsample_config.yml -
To run application on test data, update file paths containing
/data/totests/data/insample_config.yml- Example replace
/data/notes/*.orgwithtests/data/notes/*.org
- Example replace
4. Run
Load ML model, generate embeddings and expose API to query notes, images, transactions etc specified in config YAML
python3 -m src.main -c=config/sample_config.yml -vv
Upgrade On Local Machine
cd semantic-search
git pull origin master
conda deactivate semantic-search
conda env update -f config/environment.yml
conda activate semantic-search
Acknowledgments
- MiniLM Model for Asymmetric Text Search. See SBert Documentation
- OpenAI CLIP Model for Image Search. See SBert Documentation
- Charles Cave for OrgNode Parser
- Sven Marnach for PyExifTool