Sema vs Tableau

Sema is a semantic layer for enterprise AI that connects databases and answers business questions in plain English, with governance controls. It maps tables, joins, metrics, and business terms into a typed graph; verified inferred joins can be reused in later answers. It can ask clarifying questions, show the SQL and graph nodes behind an answer, and select a chart. Users can save and schedule reports for email delivery and set metric alerts for thresholds or deviations. Available connectors include PostgreSQL, MySQL, MariaDB, SQLite, and SQLAlchemy URIs; ClickHouse and Amazon Redshift are in beta, while SQL Server, Snowflake, BigQuery, Databricks, and dbt metadata are on the roadmap. Sema can run in a customer VPC or its own environment; self-hosting uses Kubernetes and Helm with customer-provided Postgres and object storage. The free Sandbox costs nothing and limits use to one connector, one user, 100 monthly chat queries, and five saved reports, without scheduled delivery or alerts. Pro costs $49 a month per user, with a three-seat minimum and a 14-day trial.

Tableau is a data analytics platform for dashboards, visualizations, and data apps. It offers hosted cloud and self-hosted server deployments, with hybrid deployment listed. Tableau Creator can connect to any type of data. Users can ask natural-language questions for AI-powered insights, while Tableau Agent provides conversational analytics inside dashboards. A knowledge engine and semantic layer support consistent metrics. Teams can publish, author, share, schedule subscriptions, and send notifications. Tableau Cloud supports secure sharing; row-level security, embedded analytics, and real-time refresh are listed. Viewer includes mobile access. Dashboards and data apps can operate across Slack, Teams, Claude, ChatGPT, CRM, and agent surfaces. Tableau has a free plan and free trial, and Tableau Desktop is free to download. Listed annual-billing prices are $15 a month for Viewer, $42 a month for Explorer, and $75 a month for Creator. Enterprise prices are also listed, while some paid pricing requires contacting sales.