The SYSIDX system view has a column "unique" that classifies the logical index as follows:

Indicates whether the index is a unique index (1), a non-unique index (4), or a unique constraint (2). A unique index prevents two rows in the indexed table from having the same values in the index columns

What does a value of 5 mean? An unique index with the new "CREATE INDEX ... WITH NULLS NOT DISTINCT" clause?

(At least that seems to be the case in my tests...)

asked 22 May '12, 07:58

Volker%20Barth's gravatar image

Volker Barth
accept rate: 34%

edited 23 May '12, 03:22

You are correct. The values are:

  • 1 - index is a unique index
  • 2 - index is for a UNIQUE constraint
  • 3 - reserved
  • 4 - index is not unique
  • 5 - index is WITH NULLS NOT DISTINCT

I will make sure that the documentation is modified appropriately. Thanks for reporting the oversight.

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answered 22 May '12, 17:29

Glenn%20Paulley's gravatar image

Glenn Paulley
accept rate: 43%

I may be hairsplitting but for the docs, I guess the description for values 1 and 5 should be worded differently as both are for unique indizes, such as:

  • 1 - index is a unique index (not declared WITH NULLS NOT DISTINCT)
  • 5 - index is a unique index WITH NULLS NOT DISTINCT

(Apparently, that would only make sense for v12 and above...)

(23 May '12, 03:21) Volker Barth
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question asked: 22 May '12, 07:58

question was seen: 2,335 times

last updated: 23 May '12, 03:22