Introduction
In today’s digital landscape, searching for information is integral to our daily lives, whether for education, research, work, or shopping. However, as the volume and complexity of data kept growing, traditional search methods faced more and more challenges in providing accurate and relevant results. That’s where vector search comes in. We’re already seeing Google changing its search engine to empower the vector search (RankBrain, BERT, Neural matching), and expecting even greater incorporation of AI tools to improve search experience. Let’s explore the differences between traditional (keyword) search and vector search to understand how these technologies are shaping our search experiences, and how this impacts the discoverability of any content you might produce.
Traditional (keyword) search
Traditional search performs exact keyword matching from user queries to the data to retrieve relevant results. For example, searching for “programming languages” with traditional search will list every source containing those words. A more advanced version can also incorporate additional rules to enhance search results, such as:
- keyword frequency (how often the term “programming languages” is used within the result text),
- the presence of related terms (e.g. “Java”, “Python”, “C++” versus “cooking”, “gardening”),
- or location (results closer to your location are favored).
While this approach has served us well, it struggles with ambiguous language, synonyms as well as the impact of SEO strategies, often resulting in less accurate or less valuable search results. This can be especially frustrating for businesses who are trying to get their content seen by the right people. For example, a business that publishes a blog post about “sustainable fashion tips” might miss out on potential customers who are searching for “eco-friendly clothing recommendations” or “green clothing ideas,” simply because their keywords don’t exactly match.
Vector (semantic) search
On the other hand, vector search takes a different approach by seeking out related objects that share similar characteristics or semantics. You can think of it as finding results based on meaning or understanding rather than just exact wording. For example, searching for “programming languages” with vector search will not only find sources mentioning those exact words but also identify specific languages like “Python” or “Java” as well as related concepts such as “coding tutorials” or“development frameworks”.
To do a vector search, first of all, the content, such as texts, images, audio files, or videos, needs to be represented as vectors/embeddings (also often called vector embeddings) by AI models. These embeddings represent data in a multidimensional vector space. Vectors capture the essence or semantics of the data they represent while remaining computationally efficient.
Once these vector representations are generated, they are basically sets of numbers, and therefore easy to compute with. For instance, instead of searching for a specific word in text, we aim to find the closest vector (from the text embeddings) to the query vector (representing the word we’re searching for). This process relies on well-established vector computing methods, such as calculating the distance between vectors or minimizing the angle between them (Cosine similarity).
Comparison
Let’s now compare different aspects of searching to understand the main differences between traditional search and vector search (also summarized in Table).
- Search Approach
In traditional search, the approach relies on matching keywords directly from the user query to the content. Vector search uses vector embeddings to catch the semantics of the data to perform a meaning-based approach. - Ambiguity handling
Therefore, vector search shines when it comes to handling ambiguity. It is superior for handling synonyms, ambiguous language, and broad or fuzzy queries compared to traditional search. This also automatically influences the relevance of the search results. - Search relevance calculation
The metrics used for search relevance calculations are different. The traditional search uses term frequency-inverse document frequency (TF-IDF) and BM25, while vector search uses Jaccard Similarity, Cosine Similarity, and L2 Distance (or Euclidean). - Speed and Implementation
Traditional search is easy to implement, straightforward in usage, and fast for simple queries. Vector search may be slower for simple queries and more complicated to implement, once it comes to huge datasets. However, the implementation of approximate nearest neighbor techniques (ANN) allows to significantly speed up the process. - Scalability
Continuous expansion of content, challenges the scalability of traditional search, while for vector search scalability is one of the advantages. - Cost
While traditional search may have lower computational requirements, the superior performance and accuracy of vector search often justify the investment in additional computing power. Furthermore, the computational costs for vector search can be significantly reduced with the use of ANN.
Conclusions
In summary, both traditional search and vector search offer distinct advantages and drawbacks. Vector search excels in handling ambiguity, correcting typos, enhancing relevance, and managing extensive datasets. Traditional search remains advantageous for straightforward queries, exact matches, or smaller datasets. Historically, limited computational resources, particularly for on-device computation (i.e. Edge Computing), favored traditional search. However, the landscape is evolving rapidly with the introduction of the first edge vector database solution by ObjectBox. This innovation promises to revolutionize the scenario by optimizing vector search for devices with constrained resources, extending the benefits of semantic search to the Edge.