HYBRID_READ

2.156 HYBRID_READ_ONLY

HYBRID_READ_ONLY enables or disables hybrid read-only mode for a pluggable database (PDB).

Property	Description
Parameter type	Boolean
Default value	`FALSE`
Modifiable	`ALTER SYSTEM`
Modifiable in a PDB	Yes
Range of values	`TRUE \| FALSE`
Basic	No
Oracle RAC	Different instances can use different values.

Hybrid read-only mode allows a PDB to operate in read/write mode or read-only mode, depending on the type of user that is connected to the PDB. The PDB operates in read/write mode for CDB common users, and read-only mode for application common users and local users. Hybrid read-only mode allows CDB common users to perform patching and maintenance operations on an open PDB, while application common users and local users can use the PDB as if it were open in read-only mode.

To enable hybrid read-only mode for a PDB, connect to the PDB and set HYBRID_READ_ONLY to TRUE. The PDB must be in READ WRITE mode before you enable hybrid read-only mode.
To disable hybrid read-only mode for a PDB, connect to the PDB and set HYBRID_READ_ONLY to FALSE.

You can determine whether a PDB is in hybrid read-only mode by querying the IS_HYBRID_READ_ONLY column of the V$CONTAINER_TOPOLOGY view.

When a PDB is in hybrid read-only mode, the OPEN_MODE column in the V$CONTAINERS and V$PDBS views reflects the mode for the querying user, that is, the OPEN_MODE column returns READ WRITE when queried by a CDB common user, and READ ONLY when queried by an application common user or a local user.

Note:

When you set the value of this parameter in a PDB to TRUE, the TRUE value will not persist when the PDB is closed and reopened. You can remedy this in one of the following ways:

Specify HYBRID READ ONLY when opening the PDB:

ALTER PLUGGABLE DATABASE pdb_name OPEN HYBRID READ ONLY;
After opening the PDB, connect to the PDB and set this parameter to TRUE again:

ALTER SYSTEM SET HYBRID_READ_ONLY = TRUE;

Note:

This parameter is available starting with Oracle AI Database 26ai.