CLEAR CACHE

Clears the content of various caches on the engine the command is executed on. This command is useful for performance testing. There is no need to call this during normal operation. Firebolt automatically evicts entries from caches that haven’t been accessed for some time. To view the current state of the cache, refer to the information_schema.engine_caches view.

Syntax

CLEAR [<cache_name>] CACHE

If a cache name is specified, clears this cache. Otherwise, clears all caches, including the caches for all tables and indexes.

CLEAR CACHE FOR [<table_or_index_name>]

Clears the cache for a specific table or index. With this, all data of the table or index needs to be fetched from object storage again. The performance will be similar to the performance on an engine that was just started.

Parameters

Parameter	Description
`<cache_name>`	The name of the cache to clear.
`<table_or_index_name>`	The name of a table or index to clear all cached data from.

Available Caches

Cache Name	Description
`EXTERNAL DATA`	Cache for external data like metadata or data files of Iceberg tables.
`QUERY`	Subresult and result cache.
`PARQUET STATISTICS`	Cache for parsed column statistics from parquet footers.
`AUTOMATED COLUMN STATISTICS`	Cache for automated column statistics.
`HISTORY BASED STATISTICS`	Cache for history-based statistics.
`VECTOR INDEX`	Clears the vector search index cache.

Example 1

The following example clears all caches on the engine the command is executed on:

CLEAR CACHE

Example 2

The following example clears the query cache on the engine the command is executed on:

CLEAR QUERY CACHE

USE ENGINE

CANCEL QUERY

⌘I

Overview

Performance and Observability

Security

Self-Managed

Managed service

Guides

SQL reference

Release notes

API reference

Legal

Syntax

Parameters

Available Caches

Example 1

Example 2

​Syntax

​Parameters

​Available Caches

​Example 1

​Example 2

Syntax

Parameters

Available Caches

Example 1

Example 2