dev: addressing code review

Author: milancermak

rig-postgres/README.md

@@ -6,8 +6,7 @@
     </picture>
     <span style="font-size: 48px; margin: 0 20px; font-weight: regular; font-family: Open Sans, sans-serif;"> + </span>
     <picture>
-        <source media="(prefers-color-scheme: dark)" srcset="https://www.postgresql.org/media/img/about/press/elephant.png">
-        <source media="(prefers-color-scheme: light)" srcset="https://www.postgresql.org/media/img/about/press/elephant.png">
+        <source srcset="https://www.postgresql.org/media/img/about/press/elephant.png">
         <img src="https://www.postgresql.org/media/img/about/press/elephant.png" width="200" alt="SQLite logo">
     </picture>
 </div>
@@ -30,8 +29,8 @@ rig-postgres = "0.1.0"
 
 You can also run `cargo add rig-core rig-postgres` to add the most recent versions of the dependencies to your project.
 
-See the [`/examples`](./examples) folder for usage examples.
+## PostgreSQL usage
 
-## Important Note
+The crate utilizes the [pgvector](https://github.com/pgvector/pgvector) extension, which is available for PostgreSQL version 13 and later. Use any of the [official](https://www.postgresql.org/download/) or alternative methods to install psql. The `pgvector` extension will be automatically installed by the crate if it's not present yet.
 
-The crate utilizes the [pgvector](https://github.com/pgvector/pgvector) PostgreSQL extension. It will automatically install it in your database if it's not yet present.
+The crate relies on [`tokio-postgres`](https://docs.rs/tokio-postgres/latest/tokio_postgres/index.html) to manage its communication with the database. You can connect to a DB using any of the [supported methods](https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNSTRING). See the [`/examples`](./examples) folder for usage examples.

rig-postgres/examples/vector_search_postgres.rs

@@ -37,12 +37,6 @@ impl PostgresVectorStoreTable for Document {
 
 #[tokio::main]
 async fn main() -> Result<(), anyhow::Error> {
-    // tracing_subscriber::fmt().with_env_filter(
-    //     tracing_subscriber::EnvFilter::from_default_env()
-    //         .add_directive(tracing::Level::DEBUG.into())
-    //         .add_directive("hyper=off".parse().unwrap())
-    // ).init();
-
     // set up postgres connection
     let database_url = std::env::var("DATABASE_URL").expect("DATABASE_URL not set");
     let db_config: tokio_postgres::Config = database_url.parse()?;

rig-postgres/src/lib.rs

@@ -149,8 +149,11 @@ impl<E: EmbeddingModel + 'static, T: PostgresVectorStoreTable + 'static> Postgre
                 .collect::<Vec<_>>()
                 .into();
 
-            let values = doc.column_values();
-            let params: Vec<&(dyn ToSql + Sync)> = values
+            // building the parameters we use in the query:
+            // first, we select only the values from the column_values() tuples
+            // and then append the embedding vector as the last parameter for the insert query
+            let column_values = doc.column_values();
+            let params: Vec<&(dyn ToSql + Sync)> = column_values
                 .iter()
                 .map(|(_, v)| &**v)
                 .chain(std::iter::once(&embedding_vector as &(dyn ToSql + Sync)))