Andres Freund <andres@anarazel.de> writes:
> On 2019-04-12 09:51:51 -0400, Tom Lane wrote:
>> Tiffany Thang <tiffanythang@gmail.com> writes:
>>> Can someone explain the use of creating multiple indexes on the same
>>> column?
>> There is none, unless the indexes have different properties (e.g.
>> different opclasses and/or index AMs).
> Well, it can be beneficial to create a new index concurrently, and then
> drop the old one concurrently.
Right, but in that situation there's no intent to keep both indexes
in place. You're just putting up with extra overhead temporarily
as a means to avoid taking an exclusive lock.
regards, tom lane
