@JING00XU Please check the Platform Support Guide

As long as the vendor is supported, you can use the vendor's own lifecycle.

I have pasted the items of intersted below:

Support Lifecycle

The support Lifecycle of a database depends on vendor Lifecycle and is not tied to a Pega Platform release. Approximately a year after a vendor releases a new version of a database, Pega extensively tests the database version against the latest Pega Platform release. All releases that are in Standard and Extended Support and all subsequent releases support the database version until the vendor end-of-support date. If a release reaches the end of Extended Support before the vendor end-of-support date, the database version is also not supported for that release after the end of Extended Support. For more information about Standard and Extended Support, see Pega Extended Support program.

Oracle Database 19c is the next “Long-Term” release. Pega Platform versions 8.4 and later have been certified with this release. Older Pega Platform releases have not been certified with 19c, in accordance with our forward-looking platform support policy. However, our testing of 19c (and 18c previously) uncovered zero compatibility issues; therefore, we have every reason to believe a system upgraded from 12c to 19c will be successful. Pega will support any Pega Platform system that has upgraded from Oracle 12c to 19c, regardless of the Pega Platform version.

We would urge you to update your Pega Platform as per the Pega Infinity Patch Calendar