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TNS-12520 connecting via the Listener and Service shows as "Blocked" and Oracle SQL Tuning Advisor is running (Doc ID 1934932.1)

Last updated on FEBRUARY 10, 2020

Applies to:

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


When attempting to connect to the Database instance via the Listener, you receive a TNS-12520 or TNS-12519 error.

A check of the listener status or services shows that the Service is "Blocked"


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