{"id":2268,"date":"2026-11-01T16:30:29","date_gmt":"2026-11-01T16:30:29","guid":{"rendered":"https:\/\/www.kingbaseglobal.com\/blog\/tech-blog\/vector-search-in-databases-hybrid-search-for-rag\/"},"modified":"2026-11-01T16:30:29","modified_gmt":"2026-11-01T16:30:29","slug":"vector-search-in-databases-hybrid-search-for-rag","status":"publish","type":"post","link":"https:\/\/www.kingbaseglobal.com\/blog\/tech-blog\/vector-search-in-databases-hybrid-search-for-rag\/","title":{"rendered":"Vector Search in Databases_ Hybrid Search for RAG"},"content":{"rendered":"<p><img decoding=\"async\" src=\"https:\/\/kingbase-bbs.oss-cn-beijing.aliyuncs.com\/qywx\/blogImage\/2d712ca6-a881-462e-bf14-8a4b253d3250.webp\" alt=\"Control console still life with unlabeled knobs representing hybrid search architecture\" \/><\/p>\n<h2>The Hybrid Search Dilemma: Why &#8216;Just Vectors&#8217; Isn&#8217;t Enough for RAG<\/h2>\n<p>Enterprise architects in Malaysia are increasingly tasked with building Retrieval-Augmented Generation (RAG) pipelines that must balance semantic relevance with strict data governance. The initial assumption that storing embeddings in a database is sufficient often fails in production. Simple vector similarity searches return results based on mathematical proximity but lack the precision required for business logic. They cannot natively enforce keyword constraints or filter by structured metadata without significant performance penalties.<\/p>\n<p>The core challenge is not storage capacity but retrieval complexity. Enterprises need hybrid search capabilities that combine full-text keyword matching (such as BM25) with vector similarity scores. This dual approach ensures that a query matches both the semantic intent and specific business terms. Furthermore, metadata filtering is mandatory for enforcing role-based access control and data residency rules. Without these features, the retrieval layer becomes a bottleneck, introducing latency spikes that degrade the user experience in real-time applications.<\/p>\n<h2>Architecture Patterns: Extending RDBMS vs. Dedicated Vector Stores<\/h2>\n<p>The decision to extend an existing relational database or deploy a dedicated vector store depends on the separation of concerns between the system of record and the retrieval layer.<\/p>\n<p>Extending a traditional Relational Database Management System (RDBMS) offers architectural simplicity. It keeps structured transactional data and unstructured embeddings in a single location. This reduces data fragmentation and simplifies backup and recovery procedures. However, running vector similarity searches on a transactional engine introduces resource contention. Vector operations are computationally intensive and can compete with Online Transaction Processing (OLTP) queries for CPU and memory. This competition often leads to unpredictable latency for critical business transactions.<\/p>\n<p>Deploying a dedicated vector database isolates the vector workload. This architecture ensures that heavy indexing and search operations do not impact the stability of the core business systems. Dedicated stores are optimized for Approximate Nearest Neighbor (ANN) algorithms and high-dimensional data. The trade-off is increased operational complexity. Data must be synchronized across multiple systems, and the application layer must handle the orchestration between the transactional database and the vector store. This integration effort increases the risk of vendor lock-in and complicates the total cost of ownership.<\/p>\n<h2>Performance Isolation: Managing Latency and Index Freshness<\/h2>\n<p>Vector workloads in RAG pipelines require frequent ingestion and updates. Embeddings must be regenerated and stored as source documents change. This high-write environment creates specific performance challenges for any database engine.<\/p>\n<p>Index freshness is a critical metric. Stale vectors lead to hallucinations or irrelevant answers in LLM responses. Maintaining low-latency retrieval under high write loads requires efficient index maintenance mechanisms. Traditional databases often struggle with this balance. They may require full table scans or complex locking mechanisms to update vector indexes, which blocks concurrent reads and writes.<\/p>\n<p>Industry benchmarks highlight the performance gap between general-purpose engines and specialized solutions. For example, ScyllaDB has published benchmarks demonstrating the construction of low-latency vector search engines capable of handling billions of vectors with minimal latency. These benchmarks serve as a reference point for understanding the performance baseline required for enterprise-grade semantic search. When evaluating existing infrastructure, architects must verify if the current engine can maintain sub-second query times while simultaneously ingesting new embeddings. If the existing database lacks native optimizations for vector index compression and ANN search, the latency overhead may exceed acceptable thresholds for real-time applications.<\/p>\n<h2>Implementation Mechanics: Hybrid Scoring and Metadata Filtering<\/h2>\n<p>Implementing hybrid search requires a clear understanding of how scoring and filtering interact. The retrieval process typically involves two distinct steps: initial filtering and final re-ranking.<\/p>\n<p>Metadata filtering must occur before or during the vector search to reduce the search space. Filtering on unindexed vector data forces a full scan, which is computationally prohibitive. Efficient implementations use inverted indexes or bitmap filters for metadata fields such as tenant ID, document type, or creation date. This ensures that the vector search engine only evaluates embeddings that meet the structural criteria.<\/p>\n<p>Hybrid scoring combines the results from keyword search and vector similarity. A common approach uses a weighted sum or reciprocal rank fusion algorithm. The application assigns a weight to the BM25 score and the cosine similarity score. This combined score determines the final ranking of the retrieved documents. Without this hybrid logic, the system either ignores keyword precision or sacrifices semantic relevance.<\/p>\n<p>Integration with LLM frameworks like LangChain or LlamaIndex requires the database to expose these capabilities through standard interfaces. The application code constructs the query, sends it to the database, and parses the ranked results. The database must support the specific data types for vectors and the functions for hybrid scoring to minimize the processing burden on the application layer.<\/p>\n<h2>Evaluating Candidates: globalSQL, ScyllaDB, and KingbaseES<\/h2>\n<p>When evaluating database solutions for vector workloads, it is essential to verify specific technical capabilities against the requirements outlined above. The following table summarizes the verified capabilities of distinct approaches, including KingbaseES as a commercial enterprise database option.<\/p>\n<table>\n<thead>\n<tr>\n<th style=\"text-align:left\">Feature<\/th>\n<th style=\"text-align:left\">globalSQL<\/th>\n<th style=\"text-align:left\">ScyllaDB<\/th>\n<th style=\"text-align:left\">KingbaseES<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"text-align:left\"><strong>Vector Search Support<\/strong><\/td>\n<td style=\"text-align:left\">Yes<\/td>\n<td style=\"text-align:left\">Yes<\/td>\n<td style=\"text-align:left\">Not Evaluated<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align:left\"><strong>Full SQL Capability<\/strong><\/td>\n<td style=\"text-align:left\">Yes (External)<\/td>\n<td style=\"text-align:left\">No (CQL\/API)<\/td>\n<td style=\"text-align:left\">Yes<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align:left\"><strong>ACID Compliance<\/strong><\/td>\n<td style=\"text-align:left\">Yes<\/td>\n<td style=\"text-align:left\">Eventual\/Strong (Configurable)<\/td>\n<td style=\"text-align:left\">Yes<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align:left\"><strong>Cloud-Native Readiness<\/strong><\/td>\n<td style=\"text-align:left\">Yes<\/td>\n<td style=\"text-align:left\">Yes<\/td>\n<td style=\"text-align:left\">Information Not Available<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align:left\"><strong>Pricing Model<\/strong><\/td>\n<td style=\"text-align:left\">Fully Managed Consumption<\/td>\n<td style=\"text-align:left\">Open Core\/Enterprise<\/td>\n<td style=\"text-align:left\">Commercial Licensing<\/td>\n<\/tr>\n<tr>\n<td style=\"text-align:left\"><strong>Performance Benchmarks<\/strong><\/td>\n<td style=\"text-align:left\">N\/A<\/td>\n<td style=\"text-align:left\">1-Billion-Vector Benchmark Available<\/td>\n<td style=\"text-align:left\">Information Not Available<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><strong>globalSQL<\/strong> presents an option for enterprises that require full SQL compatibility and ACID compliance alongside vector search. It operates as an external database solution, allowing it to integrate with existing SQL workflows while providing consumption-based pricing. This model can simplify cost forecasting for variable vector workloads. Its cloud-native architecture supports scalable deployment.<\/p>\n<p><strong>ScyllaDB<\/strong> offers a different architectural path. It is optimized for high-throughput, low-latency operations. The 1-billion-vector benchmark and technical documentation on building low-latency vector search engines provide evidence of its capability to handle massive scale. This makes it a strong candidate for applications where raw retrieval speed and index freshness are the primary constraints.<\/p>\n<p><strong>KingbaseES<\/strong> is a commercial database solution. However, there is currently no verified evidence in the available documentation confirming native support for vector search, hybrid scoring (BM25 + Vector), or metadata filtering on vector indexes. Consequently, it cannot be evaluated as a native vector search engine in this comparison. For enterprises requiring KingbaseES for its SQL and ACID capabilities, a hybrid architecture is necessary. This involves integrating KingbaseES with a dedicated vector store or an external vector search engine to handle semantic retrieval. This approach preserves KingbaseES&#8217;s role as the system of record while offloading vector workloads to a specialized component, ensuring that vector search performance does not degrade transactional integrity.<\/p>\n<h2>Data Sovereignty and Compliance in Malaysia<\/h2>\n<p>Malaysian enterprises must navigate data sovereignty and residency requirements when storing high-dimensional vector data. The Personal Data Protection Act (PDPA) governs the handling of personal information. While the PDPA does not create a blanket mandate that all data must reside locally, it imposes strict conditions on cross-border data transfers.<\/p>\n<p>Storing embeddings in a vector database introduces new compliance considerations. Embeddings can sometimes contain reconstructible information about the source text. If the source data contains personal information, the vector itself may be subject to PDPA regulations. Architects must determine if the vector storage solution allows for data residency controls.<\/p>\n<p>The choice between extending an existing database and deploying a dedicated vector store impacts compliance. Extending a local RDBMS ensures that data remains within the existing infrastructure boundaries. Deploying a dedicated vector store may involve cross-border data transfer if the vendor operates global cloud regions. Enterprises must verify the physical location of the data centers and the encryption mechanisms in transit and at rest. Any solution that processes data outside Malaysia must have clear legal agreements and technical safeguards to meet PDPA alignment.<\/p>\n<h2>Total Cost of Ownership: Licensing, Infrastructure, and Operations<\/h2>\n<p>The Total Cost of Ownership (TCO) for vector search extends beyond software licensing. It includes infrastructure scaling, operational maintenance, and integration effort.<\/p>\n<p>Licensing models vary significantly. Traditional enterprise databases often use core-based licensing, which can become expensive as vector workloads scale. In contrast, cloud-native solutions like globalSQL use a consumption-based pricing model. This aligns costs with actual usage, which can be advantageous for variable RAG workloads. Dedicated vector databases may also offer consumption pricing, but the infrastructure costs for high-performance instances can be substantial.<\/p>\n<p>Operational maintenance is a hidden cost. Index freshness requires continuous background processes. If the database lacks native optimization, DBAs must write custom scripts to manage index updates and compression. This increases the operational overhead and the risk of human error. Integration effort is another factor. Connecting the database to LLM frameworks requires development time. Solutions that offer native SQL and vector support may reduce the complexity of the application layer, lowering long-term maintenance costs.<\/p>\n<p>Architects should calculate the TCO by including the cost of scaling infrastructure for vector indexes and the labor required for index maintenance. A solution that offers full SQL capability and ACID compliance may reduce the need for separate systems, thereby lowering the overall infrastructure footprint.<\/p>\n<h2>FAQ<\/h2>\n<h3>Should we extend our current database with vector capabilities or deploy a dedicated vector database?<\/h3>\n<p>Extend your current database only if it natively supports hybrid search, metadata filtering, and low-latency indexing without degrading OLTP performance. Otherwise, a dedicated vector store provides better performance isolation and scalability for high-write workloads.<\/p>\n<h3>What are the failure modes and latency trade-offs of embedded vector search versus standalone solutions?<\/h3>\n<p>Embedded vector search can cause latency spikes in transactional systems due to resource contention. Standalone solutions isolate the workload but introduce data synchronization complexity and higher integration effort.<\/p>\n<h3>How do we ensure data sovereignty and residency compliance for vector data in Malaysia?<\/h3>\n<p>Verify the physical location of the data centers and the encryption mechanisms. Ensure that cross-border data transfers comply with PDPA alignment requirements. Vectors containing personal information may be subject to the same regulations as the source text.<\/p>\n<h3>How to implement metadata filtering with vector embeddings in SQL?<\/h3>\n<p>Use inverted indexes or bitmap filters for metadata fields such as tenant ID or document type. Apply these filters before or during the vector search to reduce the search space and avoid full table scans.<\/p>\n<h3>What are the TCO implications of dedicated vector DB vs. embedded vector search?<\/h3>\n<p>Dedicated vector DBs often use consumption pricing but require significant infrastructure and integration costs. Embedded search may reduce infrastructure footprint but increases operational overhead for index maintenance and potential licensing costs for high-performance instances.<\/p>\n<hr \/>\n<p><strong>\ud83d\udca1 More Resources<\/strong><\/p>\n<p>If you would like to dive deeper into KingbaseES and its application practices across various industries, we have compiled the following official resources to help you get started quickly and develop and operate with efficiency:<\/p>\n<ul>\n<li><a href=\"https:\/\/bbs.kingbase.com.cn\/\">Kingbase Community<\/a>: A one-stop interactive platform for technical exchanges, Q&amp;A, and experience sharing\u2014join forces with fellow DBAs and developers.<\/li>\n<li><a href=\"https:\/\/www.kingbaseglobal.com\/Solution-Oracle.html\">Kingbase Solutions<\/a>: One-stop full-stack database migration and cloud-native solutions, supporting smooth migration of multi-source heterogeneous data, ensuring high availability, real-time integration, and sustained high performance.<\/li>\n<li><a href=\"https:\/\/www.kingbaseglobal.com\/Customers.html\">Kingbase Case Studies<\/a>: Real-world user scenarios and implementation outcomes, showcasing KingbaseES&#8217;s outstanding capabilities in high availability, high performance, and IT adaptation.<\/li>\n<li><a href=\"https:\/\/docs.kingbase.com.cn\/en\">Kingbase Documentation<\/a>: Authoritative and comprehensive product manuals and technical guides, covering the entire lifecycle from installation and deployment to development, programming, and operations management.<\/li>\n<li><a href=\"https:\/\/www.kingbaseglobal.com\/Download.html\">Free Download<\/a>: Get the latest installation packages, drivers, tools, and patches, supporting multiple platforms and domestic chip architectures.<\/li>\n<li><a href=\"https:\/\/www.kingbaseglobal.com\/blog\/\">Digital Construction Encyclopedia<\/a>: Covers digital strategy planning, data integration, metrics management, database visualization applications, and more to empower enterprise digital transformation.<\/li>\n<\/ul>\n<p><strong>Open Source Resources:<\/strong><\/p>\n<ul>\n<li><a href=\"https:\/\/github.com\/hgsandy\/Kingbase-docs\">GitHub &#8211; Kingbase-docs<\/a>: Kingbase documentation open-source repository\u2014Stars and contributions are welcome.<\/li>\n<li><a href=\"https:\/\/gitee.com\/hgsandy\/kingbase-docs\">Gitee &#8211; Kingbase-docs<\/a>: Domestic mirror repository for Kingbase documentation for faster access.<\/li>\n<\/ul>\n<p>Welcome to explore the resources above and begin your Kingbase journey!<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The Hybrid Search Dilemma: Why &#8216;Just Vectors&#8217; Isn&#8217;t Enough for RAG Enterprise architects in Malaysia are increasingly tasked with building Retrieval-Augmented Generation (RAG) pipelines that must balance semantic relevance with&#8230;<\/p>\n","protected":false},"author":1379,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"meta_description":"","_kingbase_seo_description":"","footnotes":""},"categories":[1],"tags":[],"class_list":["post-2268","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/www.kingbaseglobal.com\/blog\/wp-json\/wp\/v2\/posts\/2268","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.kingbaseglobal.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.kingbaseglobal.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.kingbaseglobal.com\/blog\/wp-json\/wp\/v2\/users\/1379"}],"replies":[{"embeddable":true,"href":"https:\/\/www.kingbaseglobal.com\/blog\/wp-json\/wp\/v2\/comments?post=2268"}],"version-history":[{"count":0,"href":"https:\/\/www.kingbaseglobal.com\/blog\/wp-json\/wp\/v2\/posts\/2268\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.kingbaseglobal.com\/blog\/wp-json\/wp\/v2\/media?parent=2268"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.kingbaseglobal.com\/blog\/wp-json\/wp\/v2\/categories?post=2268"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.kingbaseglobal.com\/blog\/wp-json\/wp\/v2\/tags?post=2268"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}