# Limits and Quotas By respecting the Managed ClickHouse® restrictions and quotas, you can improve the security and productivity of your service workloads. ## Limitations From the information about restrictions on using Managed ClickHouse, you can draw conclusions on how to get your service to operate closer to its full potential. Use **Recommended approach** as guidelines on how to work around specific restrictions.
Name Description Recommended approach
Backups - one snapshot a day Since Managed ClickHouse service takes a single snapshot a day only:
  • Point-in-time recovery is not supported. A database can be restored to one of the daily backup states only.
  • When creating a database fork, you can only create a fork that matches the state of one of the backups.
  • Any data inserted before the next snapshot is lost if all nodes in a given shard malfunction and need to be replaced. This limitation doesn't apply to patches, migrations, or scaling, which are handled safely and automatically.
 N/A
Table engines support
  • Some special table engines are not supported in Managed ClickHouse.
  • Some engines are remapped to their Replicated alternatives, for example, MergeTree > ReplicatedMergeTree.
Use the available table engines listed in Supported table engines in Managed ClickHouse.
Log table engine support Log engine is not supported in Managed ClickHouse. For storing data, use a supported MergeTree family engine, which is what the Log family is usually standing in for in small tables. If what you need is to absorb many small inserts, put a Buffer table in front of a MergeTree table: Buffer is not a storage engine, it holds rows in memory and flushes them into a destination table that must already exist, and its contents are lost if the service restarts.
Kafka table engine support The Kafka table engine cannot be created directly in SQL. N/A
Cloud availability Managed ClickHouse® runs in Exoscale zones (its own European cloud), not on AWS, GCP or Azure. Choose an available Exoscale zone.
Querying all shards at once If you have a sharded plan, you must use a distributed table on top of your MergeTree table to query all the shards at the same time, and you should use it for inserts too. Use a distributed table with sharded plans. See Query data across shards.
Creating or deleting a database using SQL
  • Only the avnadmin user can create databases in SQL.
  • You can create a database in SQL with the Replicated database engine only.
  • By default, only the avnadmin user can delete a database. The avnadmin user can grant the permission to delete a database to another user.
 Create and drop databases in SQL as avnadmin, as shown in Manage Managed ClickHouse® databases and tables. Unlike Managed MySQL and Managed PostgreSQL, the DBaaS API and CLI expose no database-level operations for ClickHouse, so there is no API workaround.
Maximum number of databases per service Your Managed ClickHouse service can support up to 400 databases simultaneously. Instead of creating multiple databases of the same structure for isolation purposes, it's recommended to create one database where you add an extra column to filter by it. Consider including this column into the primary key or partitioning by it. You can also limit scope of data on which SQL queries can be run by using the additional_table_filters query setting.
## Limits Service limits are determined by a plan that this service uses. For the number of VMs, CPU per VM, RAM per VM, storage details per plan, see [Plans & pricing](https://www.exoscale.com/pricing/#dbaas). ### Plans > [!NOTE] > Disk figures are per node: allocated is the provisioned volume, usable excludes the 10% > reserved for the OS. The API `disk_space` figure corresponds to the usable disk multiplied > by the number of shards. List the plans at any time with `exo dbaas type show clickhouse --plans`. > Plans marked `Request only` are available via [our support](https://www.exoscale.com/contact/). > > The figures in the tables are binary units (GiB), while the CLI and the API report the same > quantities in decimal units (GB). A `startup-16` service therefore shows 17 GB of RAM and > 386 GB of disk in `exo dbaas type show clickhouse --plans`, which is the very same 16 GiB > and 360 GiB listed here. > [!IMPORTANT] > During early access, plan availability is granted per organization, so the plans listed > below are not all creatable on every account. List them with their `authorized` flag and > check it against your own organization before choosing a plan: > > ```bash > exo dbaas type show clickhouse --plans > ``` > > On a test account in `ch-gva-2` in July 2026, only `startup-8`, `startup-16` and > `startup-32` reported `authorized: true`; `startup-64`, `startup-128`, `startup-225`, > `startup-320` and every `premium-*` plan were listed with `authorized: false`. Contact > [our support](https://www.exoscale.com/contact/) to have a plan enabled for your > organization. **Standard plans** | Plan | Nodes | vCPU/node | RAM/node (GiB) | Allocated disk/node (GiB) | Usable disk/node (GiB) | Catalog tier | |---|---|---|---|---|---|---| | `startup-8` | 1 | 4 | 8 | 200 | 180 | Public | | `startup-16` | 1 | 4 | 16 | 400 | 360 | Public | | `startup-32` | 1 | 8 | 32 | 400 | 360 | Public | | `startup-64` | 1 | 12 | 64 | 400 | 360 | Public | | `startup-128` | 1 | 16 | 128 | 800 | 720 | Public | | `startup-225` | 1 | 24 | 225 | 800 | 720 | Public | | `startup-320` | 1 | 40 | 320 | 3200 | 2880 | Public | | `business-8` | 3 | 4 | 8 | 300 | 270 | Public | | `business-16` | 3 | 4 | 16 | 600 | 540 | Public | | `business-32` | 3 | 8 | 32 | 600 | 540 | Public | | `business-64` | 3 | 12 | 64 | 600 | 540 | Public | | `business-128` | 3 | 16 | 128 | 1200 | 1080 | Public | | `business-225` | 3 | 24 | 225 | 1200 | 1080 | Public | | `business-320` | 3 | 40 | 320 | 3200 | 2880 | Public | | `premium-6x-16` | 6 | 4 | 16 | 800 | 720 | Public | | `premium-6x-32` | 6 | 8 | 32 | 800 | 720 | Public | | `premium-6x-64` | 6 | 12 | 64 | 800 | 720 | Public | | `premium-6x-128` | 6 | 16 | 128 | 1600 | 1440 | Request Only | | `premium-6x-225` | 6 | 24 | 225 | 1600 | 1440 | Request Only | | `premium-6x-320` | 6 | 40 | 320 | 15360 | 13824 | Request Only | | `premium-9x-16` | 9 | 4 | 16 | 800 | 720 | Public | | `premium-9x-32` | 9 | 8 | 32 | 800 | 720 | Public | | `premium-9x-64` | 9 | 12 | 64 | 800 | 720 | Public | | `premium-9x-128` | 9 | 16 | 128 | 1600 | 1440 | Request Only | | `premium-9x-225` | 9 | 24 | 225 | 1600 | 1440 | Request Only | | `premium-9x-320` | 9 | 40 | 320 | 15360 | 13824 | Request Only | | `premium-12x-16` | 12 | 4 | 16 | 800 | 720 | Public | | `premium-12x-32` | 12 | 8 | 32 | 800 | 720 | Public | | `premium-12x-64` | 12 | 12 | 64 | 800 | 720 | Public | | `premium-12x-128` | 12 | 16 | 128 | 1600 | 1440 | Request Only | | `premium-12x-225` | 12 | 24 | 225 | 1600 | 1440 | Request Only | | `premium-12x-320` | 12 | 40 | 320 | 15360 | 13824 | Request Only | | `premium-15x-16` | 15 | 4 | 16 | 800 | 720 | Public | | `premium-15x-32` | 15 | 8 | 32 | 800 | 720 | Public | | `premium-15x-64` | 15 | 12 | 64 | 800 | 720 | Public | | `premium-15x-128` | 15 | 16 | 128 | 1600 | 1440 | Request Only | | `premium-15x-225` | 15 | 24 | 225 | 1600 | 1440 | Request Only | | `premium-15x-320` | 15 | 40 | 320 | 15360 | 13824 | Request Only | | `premium-18x-16` | 18 | 4 | 16 | 800 | 720 | Public | | `premium-18x-32` | 18 | 8 | 32 | 800 | 720 | Public | | `premium-18x-64` | 18 | 12 | 64 | 800 | 720 | Public | | `premium-18x-128` | 18 | 16 | 128 | 1600 | 1440 | Request Only | | `premium-18x-225` | 18 | 24 | 225 | 1600 | 1440 | Request Only | | `premium-18x-320` | 18 | 40 | 320 | 15360 | 13824 | Request Only | | `premium-21x-16` | 21 | 4 | 16 | 800 | 720 | Public | | `premium-21x-32` | 21 | 8 | 32 | 800 | 720 | Public | | `premium-21x-64` | 21 | 12 | 64 | 800 | 720 | Public | | `premium-21x-128` | 21 | 16 | 128 | 1600 | 1440 | Request Only | | `premium-21x-225` | 21 | 24 | 225 | 1600 | 1440 | Request Only | | `premium-21x-320` | 21 | 40 | 320 | 15360 | 13824 | Request Only | | `premium-24x-16` | 24 | 4 | 16 | 800 | 720 | Public | | `premium-24x-32` | 24 | 8 | 32 | 800 | 720 | Public | | `premium-24x-64` | 24 | 12 | 64 | 800 | 720 | Public | | `premium-24x-128` | 24 | 16 | 128 | 1600 | 1440 | Request Only | | `premium-24x-225` | 24 | 24 | 225 | 1600 | 1440 | Request Only | | `premium-24x-320` | 24 | 40 | 320 | 15360 | 13824 | Request Only | | `premium-27x-16` | 27 | 4 | 16 | 800 | 720 | Public | | `premium-27x-32` | 27 | 8 | 32 | 800 | 720 | Public | | `premium-27x-64` | 27 | 12 | 64 | 800 | 720 | Public | | `premium-27x-128` | 27 | 16 | 128 | 1600 | 1440 | Request Only | | `premium-27x-225` | 27 | 24 | 225 | 1600 | 1440 | Request Only | | `premium-27x-320` | 27 | 40 | 320 | 15360 | 13824 | Request Only | | `premium-30x-16` | 30 | 4 | 16 | 800 | 720 | Public | | `premium-30x-32` | 30 | 8 | 32 | 800 | 720 | Public | | `premium-30x-64` | 30 | 12 | 64 | 800 | 720 | Public | | `premium-30x-128` | 30 | 16 | 128 | 1600 | 1440 | Request Only | | `premium-30x-225` | 30 | 24 | 225 | 1600 | 1440 | Request Only | | `premium-30x-320` | 30 | 40 | 320 | 15360 | 13824 | Request Only | **Memory-optimized plans** | Plan | Nodes | vCPU/node | RAM/node (GiB) | Allocated disk/node (GiB) | Usable disk/node (GiB) | Catalog tier | |---|---|---|---|---|---|---| | `mo-startup-16` | 1 | 2 | 16 | 400 | 360 | Public | | `mo-startup-32` | 1 | 4 | 32 | 400 | 360 | Public | | `mo-startup-64` | 1 | 8 | 64 | 400 | 360 | Public | | `mo-startup-128` | 1 | 12 | 128 | 800 | 720 | Request Only | | `mo-business-16` | 3 | 2 | 16 | 600 | 540 | Public | | `mo-business-32` | 3 | 4 | 32 | 600 | 540 | Public | | `mo-business-64` | 3 | 8 | 64 | 600 | 540 | Public | | `mo-business-128` | 3 | 12 | 128 | 1200 | 1080 | Request Only | | `mo-premium-6x-16` | 6 | 2 | 16 | 800 | 720 | Public | | `mo-premium-6x-32` | 6 | 4 | 32 | 800 | 720 | Public | | `mo-premium-6x-64` | 6 | 8 | 64 | 800 | 720 | Public | | `mo-premium-6x-128` | 6 | 12 | 128 | 1600 | 1440 | Request Only | | `mo-premium-9x-16` | 9 | 2 | 16 | 800 | 720 | Request Only | | `mo-premium-9x-32` | 9 | 4 | 32 | 800 | 720 | Request Only | | `mo-premium-9x-64` | 9 | 8 | 64 | 800 | 720 | Request Only | | `mo-premium-9x-128` | 9 | 12 | 128 | 1600 | 1440 | Request Only | | `mo-premium-12x-16` | 12 | 2 | 16 | 800 | 720 | Request Only | | `mo-premium-12x-32` | 12 | 4 | 32 | 800 | 720 | Request Only | | `mo-premium-12x-64` | 12 | 8 | 64 | 800 | 720 | Request Only | | `mo-premium-12x-128` | 12 | 12 | 128 | 1600 | 1440 | Request Only | | `mo-premium-15x-16` | 15 | 2 | 16 | 800 | 720 | Request Only | | `mo-premium-15x-32` | 15 | 4 | 32 | 800 | 720 | Request Only | | `mo-premium-15x-64` | 15 | 8 | 64 | 800 | 720 | Request Only | | `mo-premium-15x-128` | 15 | 12 | 128 | 1600 | 1440 | Request Only | | `mo-premium-18x-16` | 18 | 2 | 16 | 800 | 720 | Request Only | | `mo-premium-18x-32` | 18 | 4 | 32 | 800 | 720 | Request Only | | `mo-premium-18x-64` | 18 | 8 | 64 | 800 | 720 | Request Only | | `mo-premium-18x-128` | 18 | 12 | 128 | 1600 | 1440 | Request Only | | `mo-premium-21x-16` | 21 | 2 | 16 | 800 | 720 | Request Only | | `mo-premium-21x-32` | 21 | 4 | 32 | 800 | 720 | Request Only | | `mo-premium-21x-64` | 21 | 8 | 64 | 800 | 720 | Request Only | | `mo-premium-21x-128` | 21 | 12 | 128 | 1600 | 1440 | Request Only | | `mo-premium-24x-16` | 24 | 2 | 16 | 800 | 720 | Request Only | | `mo-premium-24x-32` | 24 | 4 | 32 | 800 | 720 | Request Only | | `mo-premium-24x-64` | 24 | 8 | 64 | 800 | 720 | Request Only | | `mo-premium-24x-128` | 24 | 12 | 128 | 1600 | 1440 | Request Only | | `mo-premium-27x-16` | 27 | 2 | 16 | 800 | 720 | Request Only | | `mo-premium-27x-32` | 27 | 4 | 32 | 800 | 720 | Request Only | | `mo-premium-27x-64` | 27 | 8 | 64 | 800 | 720 | Request Only | | `mo-premium-27x-128` | 27 | 12 | 128 | 1600 | 1440 | Request Only | | `mo-premium-30x-16` | 30 | 2 | 16 | 800 | 720 | Request Only | | `mo-premium-30x-32` | 30 | 4 | 32 | 800 | 720 | Request Only | | `mo-premium-30x-64` | 30 | 8 | 64 | 800 | 720 | Request Only | | `mo-premium-30x-128` | 30 | 12 | 128 | 1600 | 1440 | Request Only | | Managed ClickHouse | Startup | Business | Premium | |---|---|---|---| | Maximum concurrent queries | Set by `max_concurrent_queries_for_all_users`, from 100 on the smallest plans | Set by `max_concurrent_queries_for_all_users` | Set by `max_concurrent_queries_for_all_users` | | Maximum concurrent connections | 4000 connections per node | 4000 connections per node | 4000 connections per node | > [!NOTE] > **Query concurrency limits** > > `max_concurrent_queries_for_all_users` is the limit your queries reach first: it caps how many > queries run at once across all users. The server-wide `max_concurrent_queries` setting is > higher, from 147 on the smallest plans, because it reserves extra capacity for monitoring, > backup, and operator queries. Both values are managed by Exoscale and scale with the service > size. For their full ranges, see > [Managed ClickHouse® 25.8 default settings](/product/dbaas/service-specific/clickhouse/reference/25-8-default-settings/). > [!NOTE] > **Total storage with a plan** > > Total storage represents the maximum amount of data you can insert into a service. It does > not grow with the number of replicas, since replicas hold another copy of the same data, but > it does grow with the number of shards. > > The inserted data is replicated on all available nodes. How many times it's replicated > depends on the number of nodes and the number of shards: > > ```math > number_of_data_replication_times = number_of_nodes / number_of_shards > ``` > > **Examples** > > - Service plan with **one shard** > > A `startup-16` plan has 360 GiB of usable disk on its single node. A `business-16` plan has > 540 GiB usable per node across three nodes that replicate the same data, so the effective > capacity remains 540 GiB. > > - Service plan with **two shards** > > A `premium-6x-16` plan has six nodes organized as two shards of three replicas each, with > 720 GiB usable per node; each shard stores its own portion of the data, for 1440 GiB of total > usable capacity. > > [!TIP] > If you need a custom plan with capacity beyond the listed limits, > [contact us](https://www.exoscale.com/contact/). ## Related pages - [Plans and pricing, including the quotas of the Business and Premium tiers](https://www.exoscale.com/pricing/#dbaas) - [Managed ClickHouse® 25.8 default settings](/product/dbaas/service-specific/clickhouse/reference/25-8-default-settings/)