How to set table TTL and TTL_GRANULARITY using ALTER TABLE?

[noobgramming]

General Question

Hi, I'm trying to set a row TTL for existing table.

This reference gives example for setting TTL on new table https://en.pingcap.com/blog/managing-you-data-lifecycle-with-time-to-live-tables/

and says You can also use ALTER TABLE to switch an existing table to a row-granularity TTL table. but does not describe how to do it.

I have tried setting like let you configure ENGINE with alter table tbl TTL='30h' and that doesn't work.

syntax reference also says nothing about it https://docs.pingcap.com/tidb/stable/sql-statement-alter-table

Can you kindly link me to documentation on this or just reply how to do it?

[noobgramming]

I can see from #22763 that I'm using proposed syntax correctly... So maybe this just isn't implemented yet

@sunxiaoguang I see you worked on that RFC and the blog post, maybe you can give me a hand on this?

[SunRunAway]

TTL feature is released with TiDB v6.5: https://docs.pingcap.com/tidb/stable/time-to-live#periodically-delete-expired-data-using-ttl-time-to-live

tracking issue: #39262