---
title: "Configuration"
id: jit-configuration
pg_version: "20devel"
---

<a id="jit-configuration"></a>

## 30.3. Configuration

The configuration variable [`jit` (`boolean`)](runtime-config-query.md#guc-jit) determines whether JIT compilation is enabled or disabled. If it is enabled, the configuration variables [`jit_above_cost` (`floating point`)](runtime-config-query.md#guc-jit-above-cost), [`jit_inline_above_cost` (`floating point`)](runtime-config-query.md#guc-jit-inline-above-cost), and [`jit_optimize_above_cost` (`floating point`)](runtime-config-query.md#guc-jit-optimize-above-cost) determine whether JIT compilation is performed for a query, and how much effort is spent doing so. 

[`jit_provider` (`string`)](runtime-config-client.md#guc-jit-provider) determines which JIT implementation is used. It is rarely required to be changed. See [Section 30.4.2](jit-extensibility.md#jit-pluggable). 

For development and debugging purposes a few additional configuration parameters exist, as described in [Section 19.17](runtime-config-developer.md).