Weaviate: Tailoring Your Data Retrieval with Property Selection
Weaviate, a powerful vector search engine, empowers you to efficiently retrieve relevant data from your knowledge graph. But what if you don't need the entire dataset for each retrieved object? This is where the ability to specify which properties to return comes into play, significantly enhancing your data retrieval experience.
Imagine searching for information about a book. You might be interested in the title and author, but not necessarily the entire synopsis or publication date. By specifying which properties to return in your Weaviate query, you can focus on retrieving only the data that matters, saving valuable bandwidth and processing time.
Why Should You Specify Properties to Return?
1. Improved Performance: Fetching only the necessary properties drastically reduces the amount of data transferred between your application and Weaviate. This results in faster query responses, a crucial aspect for any data-driven application.
2. Reduced Data Load: Retrieving fewer properties alleviates the burden on your application by minimizing the data it needs to process and manage. This is particularly important for handling large datasets or high-volume queries.
3. Enhanced Security: When retrieving sensitive data, limiting the returned properties provides a layer of security by ensuring only authorized information is exposed.
How to Specify Properties in Weaviate Queries
Weaviate offers several ways to specify the properties you want to retrieve:
1. Using the include Parameter:
This is the most common method, directly specifying the properties you want to include in the results.
Example:
const results = await weaviate.graphql.get({
query: `
query {
GetBooks {
items {
title
author {
name
}
}
}
}
`,
include: ["title", "author.name"]
});
console.log(results);
This query will fetch only the title and author.name properties for each retrieved book.
2. Using GraphQL Fields:
Weaviate's GraphQL integration offers a more structured way to define the properties you want to retrieve.
Example:
const results = await weaviate.graphql.get({
query: `
query {
GetBooks {
items {
title
author {
name
}
}
}
}
`
});
console.log(results);
This query implicitly retrieves only the title and author.name properties.
3. Using the properties Parameter:
This method can be used in combination with the include parameter to control property retrieval at different levels.
Example:
const results = await weaviate.graphql.get({
query: `
query {
GetBooks {
items {
... on Book {
title
author {
name
}
}
}
}
}
`,
properties: ["title", "author.name"]
});
console.log(results);
This query uses the properties parameter to specifically indicate the properties you want to retrieve.
4. Using a custom function:
You can create a custom function within Weaviate that determines the properties to return based on specific conditions.
Example:
// Example custom function to return only properties based on specific conditions
function returnRelevantProperties(book) {
if (book.rating >= 4.5) {
return ["title", "author.name", "rating"];
} else {
return ["title", "author.name"];
}
}
const results = await weaviate.graphql.get({
query: `
query {
GetBooks {
items {
... on Book {
returnRelevantProperties(book)
}
}
}
}
`
});
console.log(results);
This custom function dynamically selects the properties to retrieve based on the book's rating.
Tips for Optimizing Property Selection
1. Identify Essential Properties: Carefully analyze your data and application needs to determine the properties that are truly essential. Avoid unnecessary retrieval to maximize performance.
2. Leverage Object-Oriented Properties: When dealing with nested objects, use the dot notation (author.name) to specify properties within the nested structure.
3. Consider Data Integrity: If you rely on specific properties for downstream processing, ensure they are included in your queries to maintain data integrity.
4. Experiment with Different Techniques: Don't be afraid to try different methods for specifying properties to find the most efficient approach for your particular use case.
5. Use the Weaviate API Documentation: The Weaviate API documentation provides comprehensive guidance on property selection, including examples and code snippets to help you get started.
Conclusion
Specifying which properties to return is a powerful technique for optimizing your data retrieval experience in Weaviate. By carefully selecting the properties you need, you can enhance performance, reduce data load, and improve security. Embrace the flexibility Weaviate offers to tailor your queries and ensure you're getting only the data you need.