This topic describes the limits of global tables.
A global table consists of a group of replica tables that have the same name across multiple regions. Each replica is a data table that uses the wide table model. Therefore, the limits on tables, rows, columns, and operations for global tables are the same as the limits of the wide table model.
The following table describes the limits for other features of global tables.
Limitations | Limitations | Description |
Data table | Row mode | Data tables must be in row mode. You cannot create global tables from data tables that are in column mode. |
Number of replicas | 10 | A single global table supports a maximum of 10 regions. |
Auto-increment primary key column | Not supported | Auto-increment primary key columns are scoped to a single region. Cross-region replication is not supported for these columns. |
BYOK-encrypted table | Not supported | BYOK-encrypted tables require you to specify an encryption configuration for data synchronization. This is not currently supported. |
Time series table | Not supported | You cannot create global tables from time series tables. |
Time to live (TTL) | Not supported | The TTL must be set to -1, which means data never expires. |
Predefined column | Direct modification not supported | To modify the predefined columns of a global table, detach the global table to its base tables. Then, modify the predefined columns, delete the extra replica tables, and create the global table again. |
Secondary index | Synchronization not supported | Secondary indexes and search indexes on replicas are managed independently. The creation and deletion of indexes are not synchronized between replicas. |
Search index | Synchronization not supported | |
Multiple data versions and custom versions | Not supported | To ensure eventual consistency, the max versions for a global table must be set to 1. Custom versions are not supported. |
Cross-border data replication | Not supported | Global tables do not support cross-border data replication due to reasons such as data compliance. |