What's the best analytics database for fast BI dashboards with semi-structured event data and lots of concurrent users?

If your priority is fast BI dashboards over semi-structured event data with many concurrent users, the usual top picks are:

Best overall choices

1) ClickHouse

Best fit if you want:

• Very fast dashboard queries
• High concurrency
• Large-scale event analytics
• Flexible semi-structured data support via JSON / nested types
• Good cost/performance

Why it stands out

• Columnar storage is excellent for BI
• Handles millions/billions of events well
• Strong compression and indexing
• Works well for “slice and dice” analytics

Tradeoffs

• More operational complexity than some managed warehouses
• Data modeling matters to get best performance
• Not ideal for highly transactional workloads

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2) BigQuery

Best fit if you want:

• Fully managed, low ops
• Easy scaling for many users
• Strong support for semi-structured JSON data
• Great for ad hoc BI and large datasets

Why it stands out

• Serverless and simple to use
• Very good for event data
• Handles concurrency well in practice
• Easy integration with BI tools

Tradeoffs

• Can get expensive with heavy dashboard refreshes
• Performance tuning is less direct than ClickHouse
• Latency can be less predictable for very interactive dashboards

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3) Snowflake

Best fit if you want:

• Managed warehouse with strong concurrency
• Good BI ecosystem support
• Semi-structured data via VARIANT
• Easier enterprise operations

Why it stands out

• Separate compute and storage
• Easy to scale warehouses for concurrency
• Strong governance and sharing features
• Mature enterprise choice

Tradeoffs

• Often more expensive than ClickHouse
• For ultra-low-latency dashboards, may not be as fast/cost-efficient as ClickHouse

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Quick recommendation by scenario

• Fastest dashboards at high scale, cost-sensitive: ClickHouse
• Lowest ops, managed/serverless, easy to start: BigQuery
• Enterprise warehouse with concurrency and governance: Snowflake

If I had to pick one

For fast BI dashboards + semi-structured event data + lots of concurrent users, I’d usually pick ClickHouse if you’re comfortable running or managing it.
If you want the simplest managed option, choose BigQuery or Snowflake depending on your cloud and governance needs.

Important caveat

The “best” database depends heavily on:

• Query patterns
• Freshness requirements
• Data volume
• Cloud provider
• Cost constraints
• Whether dashboards hit pre-aggregated tables or raw events

If you want, I can give you a side-by-side comparison of ClickHouse vs BigQuery vs Snowflake vs Redshift for your exact use case.