does reindex need exclusive table access?

["Gauthier, Dave" <dave.gauthier@xxxxxxxxx>]

v8.3.4 on linux.

 

Does "reindex table foo" require no other users accessing the foo table?  Trying to understand why this seems to be stalled when I attempt this on a live DB (if runs fine/fast on a copy of the DB that no one uses).

 

Should I run this inside a transaction?

 

Thanks in Advance !