DolphinDB Limits
This section describes the common usage limits of DolphinDB, including the number and size limits for user and permission management, network connections, database objects, data types, queries and transactions, as well as system resources.
| Item | Upper Limit |
|---|---|
| Number of users | Unlimited |
| Number of user groups | Unlimited |
| Number of users per group | Unlimited |
| Number of connections | Constrained by maxConnections (when modified via
setMaxConnection, the upper limit is
65,536) |
| Number of variables per session | Unlimited |
| Number of shared variables | 65,536 |
| Number of function views | Unlimited |
| Number of scheduled jobs | Unlimited |
| Number of databases | Unlimited |
| Number of tables | Unlimited |
| Number of partitioning columns per COMPO domain | 3 |
| Number of partitions | Unlimited |
| Rows per partition | 2,147,483,648 |
| Rows per table |
In-memory table: 2,147,483,648 Others: Unlimited |
| Columns per table | Unlimited |
| Length of STRING type |
DFS table: 65,536 bytes (64KB) OLTP table: when specified as an indexed field, the upper limit is 4,096 bytes In-memory table: Unlimited |
| Length of BLOB type |
DFS table: 67,108,864 bytes (64MB) Others: Unlimited |
| Length of SYMBOL type |
DFS table: 256 bytes Others: Unlimited |
| Number of distinct values for a SYMBOL column per partition | 2,097,152 |
| Size of a SQL query result |
DFS table: 80% of total memory Others: Unlimited |
| Number of partitions for a SQL query | Constrained by maxPartitionNumPerQuery |
| Execution time for a transaction | Unlimited |
| Execution time for a query | Unlimited |
| Usable memory size | Constrained by license, available memory, and the configuration parameter maxMemSize |
| Usable CPU cores | Constrained by license, CPU cores, and the configuration parameter workerNum |
| Number of nodes in the cluster | Constrained by license |