# Limits

This document provides hard and soft limits in ScyllaDB.

## Cluster and Node Limits

| Component         | Limit        |
|-------------------|--------------|
| Nodes per cluster | Low hundreds |
| Node size         | 4096 CPUs    |

See [Hardware Requirements](https://docs.scylladb.com/manual/master/getting-started/system-requirements.md#system-requirements-hardware) for storage
and memory requirements and limits.

## CQL Limits

| Component                                          | Limit                                                                                                     |
|----------------------------------------------------|-----------------------------------------------------------------------------------------------------------|
| Keyspaces per cluster                              | Thousands (tested with 1000)                                                                              |
| Tables per keyspace                                | Low thousands (tested with 5000)                                                                          |
| Tables per cluster (including indexes)             | Thousands                                                                                                 |
| Tables with CDC enabled                            | No limit. CDC can be enabled for all tables in a cluster.                                                 |
| Materialized views and secondary indexes per table | Low tens                                                                                                  |
| Columns per table                                  | Hundreds                                                                                                  |
| Columns per cluster                                | Tens of thousands                                                                                         |
| Partition size                                     | Gigabytes                                                                                                 |
| Rows per partition                                 | No limit                                                                                                  |
| Row size                                           | Latency-related soft limit:<br/><br/>Hundreds of kilobytes (good latency) or megabytes (mediocre latency) |
| Key length                                         | 65533                                                                                                     |
| Keyspace / Table / View / Index name length        | 192 characters                                                                                            |
| Query parameters in a query                        | 65535 (2^16-1)                                                                                            |
| Statements in a batch                              | 65535 (2^16-1)                                                                                            |
| Fields in a tuple                                  | 32768 (2^15) (just a few fields, such as 2-10, are recommended)                                           |
| Collection (List)                                  | ~2 billion (2^31)                                                                                         |
| Collection (Set)                                   | ~2 billion (2^31)                                                                                         |
| Collection (Map)                                   | Number of keys: 65535 (2^16-1)                                                                            |
| Blob size                                          | 2 GB ( less than 1 MB is recommended)                                                                     |
| Dimension of a vector                              | 16000 (according to OpenSearch limitations)                                                               |