-XX:[+|-]UseCompressedOops (Java option used for the compressed object pointer functionality)
- Organization of this page
Format
- -XX:+UseCompressedOops
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This specification enables the compressed object pointer functionality.
- -XX:-UseCompressedOops
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This specification disables the compressed object pointer functionality.
Description
This option specifies whether to enable the compressed object pointer functionality. This functionality manages Java objects by compressing their size. By using this functionality, the usage of the Java heap area and Explicit heap area can be reduced during Java VM execution.
Note that the Explicit heap area is available only if the Explicit Memory Management functionality is enabled. This functionality can be enabled when the following condition is met:
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The total value of the sizes specified for the Java heap area, metaspace area, and Explicit heap area is less than 32 GB.
When a Java VM starts, if the total value of the sizes specified for the Java heap area, metaspace area, and Explicit heap area is 32 GB or more, the Java VM disables the compressed object pointer functionality and outputs the following message to the standard output:
Java HotSpot(TM) 64-Bit Server VM warning: Max heap size too large for Compressed Oops
- Default value
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-XX:-UseCompressedOops
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