My Oracle Support Banner

Hang may occur if IS JSON STRICT WITH UNIQUE KEYS is used (Doc ID 2771814.1)

Last updated on APRIL 26, 2021

Applies to:

Oracle Database - Enterprise Edition - Version and later
Information in this document applies to any platform.


'library cache lock' contention is observed and a DDL hangs if a check constraint is created with "is json strict with unique keys" option.

The following DDL hangs:

The hanganalyze shows that the blocker process is consuming high CPU and PGA memory.

alter table add check (jo_content is json) - this works
alter table add check (jo_content is json strict) - this works
alter table add check (jo_content is json strict with unique keys) - this hangs

Clean shutdown of the instance also hangs after that.


To view full details, sign in with your My Oracle Support account.

Don't have a My Oracle Support account? Click to get started!

In this Document

My Oracle Support provides customers with access to over a million knowledge articles and a vibrant support community of peers and Oracle experts.