Patches to apply before upgrading Oracle GI and DB to 12.2 , 18c and 19c

Patches to apply before upgrading Oracle GI and DB to 12.2.0.1 (Doc ID 2180188.1)

https://support.oracle.com/epmos/faces/DocumentDisplay?parent=DOCUMENT&sourceId=2308775.1&id=2180188.1&_adf.ctrl-state=cb554i83i_143&_afrLoop=78350518288050

Patches to apply before upgrading Oracle GI and DB to 18c or downgrading to previous release (Doc ID 2414935.1)

https://support.oracle.com/epmos/faces/DocumentDisplay?_afrLoop=78295018483823&id=2414935.1&displayIndex=2&_afrWindowMode=0&_adf.ctrl-state=cb554i83i_253

Patches to apply before upgrading Oracle GI and DB to 19c or downgrading to previous release (Doc ID 2539751.1)

https://support.oracle.com/epmos/faces/DocumentDisplay?_afrLoop=78293517180665&id=2539751.1&displayIndex=1&_afrWindowMode=0&_adf.ctrl-state=cb554i83i_212