In 19c17, creation of PDBs longer and longer when the number of PDBs increases. Never seen in 12c.

We have migrated our activity from Linux Oracle Enterprise 12.2 to the last 19.17 Linux.

Our activity is to test several scenario by using a lot of PDBs (copies or snapshot) per day: at least 1200 to 1500 pdbs.

The sizing is about 4Gb per pdb, and in 12.2, we created a pdb in 30s, all the times during 3 years without issue.

Now in 19c17 (new created instance and patches on a new Linux Redhat machine):

• At the beginning we created a pdb in 6 s (very fast).
• But gradually, creations beyond 50 PDBS, the time increases exponentially. we go to 1mn, or even exceed 20mns if we exceed 100 pdbs online (never seen in 12c).