BigQuery NL2SQL Without Hallucinations? Querio Has the Guardrails

Business Intelligence

Jul 26, 2025

Querio tackles AI hallucinations in SQL queries, ensuring accurate BigQuery analytics through validation, governance, and security measures.

AI-generated SQL queries can go wrong, but Querio solves this problem.

Querio ensures accurate and secure BigQuery analytics by embedding validation checks, enforcing data governance rules, and offering enterprise-grade security. This prevents errors like "AI hallucinations", where queries reference nonexistent database elements, leading to flawed insights or compliance risks.

Key takeaways:

  • AI Hallucinations Risk: Models generate SQL queries that look correct but reference invalid or missing data.

  • Querio’s Solution: Built-in validation, governance layers, and security measures reduce errors and ensure compliance.

  • Enterprise Features: SOC 2 Type II certification, 99.9% uptime, and centralized data rules for consistent results.

  • Pricing: Starts at $14,000/year with modular add-ons and unlimited viewers.

Querio bridges the gap between natural language and accurate SQL, empowering teams to access reliable insights without needing SQL expertise.

What NL2SQL Hallucinations Are and Why They're Dangerous

What Are NL2SQL Hallucinations?

NL2SQL hallucinations happen when an AI generates SQL queries that look correct but include elements that don't actually exist in the database. As Gatha Varma, PhD, explains:

"An AI hallucination is a confident response by the model that cannot be grounded in any of its training data." [3]

These issues occur because large language models create text based on patterns they've learned, not an actual understanding of the database schema [3]. For instance, imagine a BigQuery database with a sales table that only includes product_id, units_sold, and sale_date. If asked for regional product performance, an NL2SQL system might produce:

SELECT product_name, revenue
FROM sales
WHERE region = 'EMEA';

While this query is syntactically correct, columns like product_name, revenue, and region don't exist in the schema. The system essentially "makes up" these elements, likely because they are commonly seen in sales-related queries [3].

Business Impact of Wrong Query Results

Incorrectly generated queries can lead to bad insights, poor decisions, and even compliance issues [5]. The problem is compounded because most end users can't verify the accuracy of SQL queries before using the results. This increases the risk of decisions based on flawed data. For example, current LLM-based Text-to-SQL models achieve an execution accuracy of about 73% on the BIRD benchmark [5], meaning nearly 1 in 4 queries could be wrong.

Errors like these aren't just inconvenient - they can result in serious consequences. Organizations subject to regulations like SOX or GDPR could face audit failures or penalties if inaccurate data is used [2]. Teams across the company are affected, from finance to sales to executives, all of whom depend on reliable data for tasks like budgeting, forecasting, and reporting. When an AI system delivers incorrect results, decision-makers could unknowingly act on misleading information.

When Hallucinations Happen Most Often

A 2024 Gartner survey revealed that reasoning errors caused by hallucinations are a major concern for AI systems, with 59% of respondents citing this as a key risk [6]. These errors often arise when user queries are vague or unclear, forcing the AI to "fill in the blanks." For example, a query like "show me our best products" could leave the model guessing whether "best" means highest revenue, most units sold, best profit margins, or top customer reviews.

Even advanced models struggle with consistency. ChatGPT, for instance, has a contradiction rate of 14.3% [4]. The most dangerous hallucinations occur when the system generates queries that execute successfully but produce incorrect data. Decision-makers may trust these results without realizing they are flawed, leading to potentially harmful outcomes.

These risks underscore the importance of rigorous validation processes - something that tools like Querio aim to address.

Write queries in BigQuery using Duet AI | Duet AI for BigQuery

BigQuery

How Querio Prevents Wrong SQL Queries in BigQuery

Querio

Querio minimizes the risk of incorrect NL2SQL (natural language to SQL) conversions by combining automated query checks, a strong data governance framework, and enterprise-level security. These features ensure every query is thoroughly validated before it runs, addressing potential risks proactively.

Built-in Query Validation

Querio integrates BigQuery’s native validation tools with additional, more advanced checks. When you input a question in plain English, Querio converts it into SQL and then subjects it to a series of rigorous validation processes.

The platform performs both syntactic and semantic checks to confirm that the SQL is correctly structured, all referenced tables and columns exist, and data types align properly [7][8].

Querio also takes advantage of BigQuery’s "dry run" feature, which allows validation without actually executing the query. This method ensures that syntax, table and column existence, data type compatibility, and access permissions are verified without incurring any costs [7].

Data Governance Controls

Querio’s context layer empowers data teams to establish and enforce organizational rules, such as defining table joins, standardizing metric calculations, and mapping business terms to technical equivalents. This structured approach reduces errors caused by misinterpretation or ambiguity.

For instance, data teams can create a centralized glossary that connects business terms to their technical implementations. If a user asks about "monthly recurring revenue", Querio knows exactly which tables to query, how to handle date ranges, and what calculations to apply. This ensures consistent outcomes across teams and departments.

Additionally, Querio enforces strict access controls. By connecting directly to your BigQuery instance using read-only, encrypted credentials, the platform protects sensitive data while enabling self-service analytics.

Security Feature

Details

Direct data warehouse connection

✓ Read-only, encrypted credentials

Built-in access controls

✓ Granular permissions

SOC 2 Type II compliance

✓ Certified

Data governance layer

✓ Centralized definitions

Real-time data processing

✓ Live connections

Security and Uptime for US Companies

In addition to validation and governance, Querio delivers robust security and high availability, making it a reliable choice for businesses in regulated industries. The platform guarantees 99.9% uptime and is SOC 2 Type II certified, demonstrating its commitment to safeguarding customer data with strict standards for security, availability, and confidentiality [9].

Security measures include end-to-end encryption, detailed access controls, and regular audits [9]. All connections to BigQuery are encrypted, and query activity logs are maintained to support compliance requirements and audits.

Querio’s 99.9% uptime ensures your analytics workflows are always available, which is crucial for organizations relying on real-time data to make critical decisions. For companies subject to regulations like SOX or GDPR, these comprehensive safeguards ensure that analytics processes remain secure, compliant, and reliable.

Using Querio for Accurate BigQuery Analytics

Querio combines user-friendly query tools with strong governance to simplify BigQuery analytics. It allows users to ask questions in plain language while ensuring SQL queries remain accurate and reliable for quick decision-making.

Ask Questions in Plain English

Querio lets users type questions in everyday language, translating them into precise BigQuery SQL queries. It even formats dates, currency, and numbers according to U.S. conventions.

For instance, if you ask, "What was our revenue last quarter?" Querio ensures proper fiscal alignment and selects the right database tables. If your question includes ambiguous terms, like "customers", and your database has separate tables for "active_customers" and "trial_customers", Querio will prompt you to clarify which group you mean.

The platform is particularly adept at handling complex requests that would normally demand advanced SQL skills. For example, a question like "Show me the month-over-month growth rate for our top 10 products by revenue" is seamlessly converted into an accurate query. However, clarity is key - asking one focused question at a time ensures better results than combining multiple requests into a single query [10].

Querio tackles common NL2SQL (natural language to SQL) challenges by breaking down complex questions into smaller components. It also uses semantic searches to connect business terms with their technical counterparts [1]. This means non-technical users, such as marketing managers or business analysts, can easily access BigQuery data without needing SQL expertise.

This precise query conversion paves the way for creating detailed reports and dashboards with minimal effort.

Create Dashboards and Scheduled Reports

Once queries are validated, they can be directly transformed into visual dashboards or scheduled reports. Querio’s user-friendly interface allows you to build KPI dashboards from these queries, ensuring that executives and teams receive consistent, reliable analytics.

Scheduled reports follow the same validation rules as individual queries. They can run at set intervals, delivering results via email or real-time dashboard updates. This automation eliminates the repetitive work of creating recurring reports while maintaining accuracy with Querio’s built-in safeguards.

Dashboards refresh with live BigQuery data, offering executives real-time insights. Reports can also be tailored for specific stakeholders, ensuring users only see data they’re authorized to access. The same governance that ensures accuracy in individual queries extends to all reports and dashboards, promoting consistent data interpretation across the organization.

Set Up Data Standards Once

Data teams can establish a context layer that maps business terms to technical structures, ensuring Querio’s safeguards apply consistently to all queries. This setup is a one-time effort that enables reliable analytics for all users without requiring manual adjustments for each query [1].

For example, when data engineers define table relationships, standardize calculations, and create a business glossary, questions about "customer lifetime value" automatically reference the right tables, time periods, and account for scenarios like refunds or cancellations. This structure eliminates ambiguity, ensuring all users interpret metrics the same way [1].

This governance framework is scalable. Once the context layer is in place, business users across the organization can ask questions in familiar terms while getting technically accurate results. Data integrity is preserved by enforcing these standards, avoiding the inconsistencies that can arise when different teams interpret metrics differently.

As business needs evolve or new data sources are integrated, data teams can update definitions centrally. This ensures all analytics stay aligned with current business logic without requiring individual updates to reports or dashboards.

Why US Companies Choose Querio

US businesses are under constant pressure to make quick, data-driven decisions while ensuring accuracy and compliance with regulations. Querio tackles these challenges by offering AI-powered analytics paired with clear pricing and governance features that align with US laws.

Fast and Accurate Results

Querio eliminates the need for manual SQL query writing, a common bottleneck in business intelligence workflows. Its built-in validation tools catch errors early and automatically apply correct formats - like MM/DD/YYYY for dates and $ for currency - ensuring the results are both precise and ready for immediate use.

This means business teams don’t have to rely on data analysts for custom queries. Marketing managers can instantly view campaign performance, finance teams can access real-time revenue data, and executives can check updated KPI dashboards - all without delays. This agility gives companies a competitive edge, enabling them to respond more quickly to market shifts and customer demands.

Clear Pricing and Unlimited Users

Cost predictability is just as important as performance. Querio’s pricing model eliminates the budget uncertainties often associated with enterprise software. Here’s how it breaks down:

  • Core Platform: $14,000/year (includes one connection, 4,000 monthly prompts, and unlimited viewers).

  • Dashboards Add-On: $6,000/year.

  • Extra Database Connections: $4,000 each annually.

  • Data-Pipelines Subscription: $10,000/year for up to three pipelines.

This straightforward structure allows companies to budget with confidence, avoiding unexpected per-user fees as their teams expand. The unlimited viewer model is a standout feature, enabling businesses to share dashboards and reports across entire teams - from executives to front-line managers - without additional licensing costs.

For growing businesses, this modular pricing approach is especially appealing. Startups can begin with the Core Platform and add features as their needs evolve, while larger enterprises can calculate total costs upfront. Querio also offers a monthly billing option (with a 10% surcharge), providing flexibility for companies with seasonal cash flow or those preferring operational expense budgets.

Built for Compliance and Control

In highly regulated industries, compliance is non-negotiable. US companies operate in one of the most tightly governed environments, where lapses can lead to costly penalties. As Deputy Attorney General Lisa O. Monaco emphasized:

"A corporate strategy that puts profits over compliance isn't a path to riches; it's a path to federal prosecution." [11]

Querio’s governance framework helps businesses avoid these pitfalls by offering controlled and auditable data access. Role-based access controls ensure compliance with industry regulations, whether it’s HIPAA for healthcare or SEC rules for financial services.

The platform’s context layer allows data teams to define business rules and access permissions centrally, ensuring consistent standards across departments. This not only supports compliance but also prevents discrepancies in how metrics are interpreted - an issue that can lead to regulatory reporting errors.

Querio’s SOC 2 Type II certification and 99.9% uptime SLA further reassure businesses of its reliability and security. Features like read-only database connections and encrypted credentials protect sensitive data while maintaining high performance.

For companies juggling multiple compliance mandates, Querio’s unified governance approach simplifies the process. By integrating governance, risk management, and compliance (GRC) strategies, businesses can operate more efficiently, make better decisions, and meet the growing demand for transparency from regulators [12].

Conclusion: Reliable AI Analytics with Querio

NL2SQL hallucinations can undermine decision-making and erode trust in data. Querio tackles this issue directly with a robust approach that blends schema grounding, semantic modeling, and iterative validation to ensure every query delivers accurate, actionable insights.

Querio’s safeguards are designed to prevent errors at every step. The platform’s Metadata Definition Language (MDL) creates a clear semantic layer, standardizing data and eliminating ambiguity. By combining a schema-first approach with contextual query routing and step-by-step reasoning, Querio removes the guesswork that often leads to faulty SQL generation. These measures are part of a broader system aimed at supporting strategic business goals.

The impact goes beyond technical accuracy. By leveraging schema grounding, semantic modeling, retrieval augmentation, validation, and transparency, Querio reduces hallucinations by up to 50% [13]. Its validation tools not only sanitize inputs to prevent SQL injection but also ensure every query aligns with your organization’s data governance policies.

For US enterprises, Querio offers strong compliance features to protect sensitive information. Role-based access controls, encrypted credentials, and read-only database connections create a secure environment for data exploration. These features work within Querio’s governance framework to maintain consistency and trust across all queries.

Querio redefines business intelligence by making precise data insights accessible to everyone - whether it’s a marketing manager analyzing campaign performance or an executive monitoring KPIs - all without requiring SQL expertise. Transparent reasoning steps and dry-run validation ensure that plain English queries yield accurate results.

This level of reliability enables teams to make faster, more confident decisions. When data tools are trusted, teams can focus on insights rather than second-guessing, fostering the agility US companies need to stay competitive in fast-paced markets.

FAQs

How does Querio ensure accurate SQL queries without AI hallucinations?

Querio employs sophisticated validation systems and integrated safeguards to maintain the precision of NL2SQL queries. These tools carefully scrutinize and verify the generated SQL to ensure it aligns with the intended logic, minimizing the chance of mistakes or inaccuracies.

By rigorously checking queries before they run, Querio delivers dependable results in BigQuery, empowering you to make quick, informed decisions with peace of mind.

How can AI-generated SQL errors, like hallucinations, impact business decisions and compliance?

AI-generated SQL queries that "hallucinate" can cause major problems, including misleading insights and poor decision-making. These errors could lead to incorrect financial or regulatory reporting, putting compliance at risk, creating potential legal liabilities, and eroding trust with stakeholders.

To avoid these pitfalls, it's crucial to use AI tools that come with strong validation processes and governance features. This helps ensure your data remains accurate and dependable, supporting sound decision-making every step of the way.

How does Querio's pricing adapt to support businesses as their data needs grow?

Querio provides a pricing model that adjusts to fit your business, no matter its size. Whether you're running a small team or managing a growing organization with bigger data needs, Querio's tiered plans are built to meet you where you are.

As your business grows, upgrading is simple. Larger plans offer support for bigger teams, more advanced features, and extra resources, so you always have what you need - without paying for things you won’t use.

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