layout: global title: CACHE TABLE displayTitle: CACHE TABLE license: | Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file distributed with this work for additional information regarding copyright ownership. The ASF licenses this file to You under the Apache License, Version 2.0 (the “License”); you may not use this file except in compliance with the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
CACHE TABLE
statement caches contents of a table or output of a query with the given storage level. If a query is cached, then a temp view will be created for this query. This reduces scanning of the original files in future queries.
CACHE [ LAZY ] TABLE table_identifier [ OPTIONS ( 'storageLevel' [ = ] value ) ] [ [ AS ] query ]
LAZY
Only cache the table when it is first used, instead of immediately.
table_identifier
Specifies the table or view name to be cached. The table or view name may be optionally qualified with a database name.
Syntax: [ database_name. ] table_name
OPTIONS ( ‘storageLevel’ [ = ] value )
OPTIONS
clause with storageLevel
key and value pair. A Warning is issued when a key other than storageLevel
is used. The valid options for storageLevel
are:
NONE
DISK_ONLY
DISK_ONLY_2
DISK_ONLY_3
MEMORY_ONLY
MEMORY_ONLY_2
MEMORY_ONLY_SER
MEMORY_ONLY_SER_2
MEMORY_AND_DISK
MEMORY_AND_DISK_2
MEMORY_AND_DISK_SER
MEMORY_AND_DISK_SER_2
OFF_HEAP
An Exception is thrown when an invalid value is set for storageLevel
. If storageLevel
is not explicitly set using OPTIONS
clause, the default storageLevel
is set to MEMORY_AND_DISK
.
query
A query that produces the rows to be cached. It can be in one of following formats:
SELECT
statementTABLE
statementFROM
statementCACHE TABLE testCache OPTIONS ('storageLevel' 'DISK_ONLY') SELECT * FROM testData;