# Properties reference#

This section describes the most important configuration properties and (where applicable) their corresponding session properties, that may be used to tune Trino or alter its behavior when required. Unless specified otherwise, configuration properties must be set on the coordinator and all worker nodes.

The following pages are not a complete list of all configuration and session properties available in Trino, and do not include any connector-specific catalog configuration properties. For more information on catalog configuration properties, refer to the connector documentation.

## Property value types#

Trino configuration properties support different value types with their own allowed values and syntax. Additional limitations apply on a per-property basis, and disallowed values result in a validation error.

### boolean#

The properties of type boolean support two values, true or false.

### data size#

The properties of type data size support values that describe an amount of data, measured in byte-based units. These units are incremented in multiples of 1024, so one megabyte is 1024 kilobytes, one kilobyte is 1024 bytes, and so on. For example, the value 6GB describes six gigabytes, which is (6 * 1024 * 1024 * 1024) = 6442450944 bytes.

The data size type supports the following units:

• B: Bytes

• kB: Kilobytes

• MB: Megabytes

• GB: Gigabytes

• TB: Terabytes

• PB: Petabytes

### double#

The properties of type double support numerical values including decimals, such as 1.6. double type values can be negative, if supported by the specific property.

### duration#

The properties of type duration support values describing an amount of time, using the syntax of a non-negative number followed by a time unit. For example, the value 7m describes seven minutes.

The duration type supports the following units:

• ns: Nanoseconds

• us: Microseconds

• ms: Milliseconds

• s: Seconds

• m: Minutes

• h: Hours

• d: Days

A duration of 0 is treated as zero regardless of the unit that follows. For example, 0s and 0m both mean the same thing.

Properties of type duration also support decimal values, such as 2.25d. These are handled as a fractional value of the specified unit. For example, the value 1.5m equals one and a half minutes, or 90 seconds.

### integer#

The properties of type integer support whole numeric values, such as 5 and 1000. Negative values are supported as well, for example -7. integer type values must be whole numbers, decimal values such as 2.5 are not supported.

Some integer type properties enforce their own minimum and maximum values.

### string#

The properties of type string support a set of values that consist of a sequence of characters. Allowed values are defined on a property-by-property basis, refer to the specific property for its supported and default values.