От: Jeffrey Tenny
Тема: Redundant indexes?
Дата: ,
Msg-id: 429790E1.5040308@comcast.net
(см: обсуждение, исходный текст)
Ответы: Re: Redundant indexes?  (Tom Lane)
Список: pgsql-performance

Would I be correct in assuming that the following two indexes are
completely redundant except for the fact that one complains about
uniqueness constraint violations and the other does not?

Or is there are legitimate use for having BOTH indexes?

I'm trying to figure out if it's okay to delete the non-unique index.
(I have a bunch of tables suffering this malady from some problematic
application code).

     Table "public.erf"
      Column |  Type   | Modifiers
      rid    | integer | not null
      cid    | integer | not null
     Indexes: erf_rid_key unique btree (rid),
         erf_rid_idx btree (rid)

     Index "public.erf_rid_idx"
      Column |  Type
      rid    | integer
     btree, for table "public.erf"

     Index "public.erf_rid_key"
      Column |  Type
      rid    | integer
     unique, btree, for table "public.erf"

В списке pgsql-performance по дате сообщения:

От: Tom Lane
Сообщение: Re: Redundant indexes?
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Сообщение: Re: OID vs overall system performances on high load