--- title: "When Column Names Lie: Bringing External Catalogs to NL2SQL++" url: https://daily.dev/posts/when-column-names-lie-bringing-external-catalogs-to-nl2sql--nprdiakbm source_url: https://www.couchbase.com/blog/when-column-names-lie-bringing-external-catalogs-to-nl2sql type: article source: "Couchbase" published: 2026-08-03T20:49:29.883Z updated: 2026-08-03T20:49:54.055Z tags: ["llm", "vector-search", "couchbase"] reading_time: 9 upvotes: 0 comments: 0 language: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # When Column Names Lie: Bringing External Catalogs to NL2SQL++ **[Couchbase](https://daily.dev/sources/couchbase)** · 9 min read · 0 upvotes · 0 comments ## Summary Hardcoding schema into NL2SQL prompts fails when column names are opaque, misleading, or near-duplicate — a common reality in enterprise data. This project connects external data catalogs (DataHub, OpenMetadata) to Couchbase so that column descriptions, not just names, inform SQL++ generation. Column descriptions are embedded as 384-dimension vectors and stored in Couchbase; at query time, vector search retrieves semantically relevant columns, which are then passed to a Claude model on AWS Bedrock to generate correct SQL++. A pluggable provider pattern means switching catalogs is a config change. Two concrete examples show how schema-only approaches silently return wrong results — correct SQL that filters on invented string values or picks the wrong near-duplicate column — while catalog-enhanced queries get the right answer because the encoding or tolerance clause is in the description. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [Medium](https://daily.dev/posts/medium-ie9499vpq) · Medium · 0 upvotes · 0 comments - [Snowflake’s Catalog-Linked Databases, Simplifying Data Estates](https://daily.dev/posts/snowflake-s-catalog-linked-databases-simplifying-data-estates-zfrpuewti) · Snowflake Community · 0 upvotes · 0 comments - [Interoperability Series: Snowflake & Databricks: External-First CLD](https://daily.dev/posts/interoperability-series-snowflake-databricks-external-first-cld-mpsiptp39) · Snowflake Community · 0 upvotes · 0 comments --- Tags: [#llm](https://daily.dev/tags/llm), [#vector-search](https://daily.dev/tags/vector-search), [#couchbase](https://daily.dev/tags/couchbase) [View this post on daily.dev](https://daily.dev/posts/when-column-names-lie-bringing-external-catalogs-to-nl2sql--nprdiakbm)