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Message Posted: Fri, 09 Dec 2005 @ 15:07:09 GMT


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Subj:		Re: Index Type

From:		Dieter Noeth

David Clough wrote:

Can anyone tell me what the difference is between types 'O' and 'V' is, as well as the difference between 'S' and 'H' from the statement below, which is derived from dbc.Indices:

          > CASE IndexType
          > WHEN 'S' THEN 'Secondary'
          > WHEN 'U' THEN 'Unique Constraint'
          > WHEN 'V' THEN 'Value Ordered'
          > WHEN 'J' THEN 'Join Index'
          > WHEN 'N' THEN 'Hash Index'

     WHEN 'O' THEN 'Value Ordered Secondary (All)'
     WHEN 'H' THEN 'Hash Ordered Secondary (All)'
     when 'K' then 'Primary Key'
     when '1' then 'Compressed Join Index (fixed part)'
     when '2' then 'Compressed Join Index (repeating group)'
     when 'I' then 'Value Ordered (ordering column)'

ELSE IndexType END (TITLE 'Type')

Basically I want to highlight any Join Indexes or any type of secondary index on a specified table, but I'm unclear what the 'O's and 'H's are.

There's an ALL option in "create index", it's about case sensitivity for char columns.

'aa', 'Aa', 'aA', 'AA' -> one index row without ALL, but 4 with ALL

Check the DDL manual for "create index"/"create join index" for a bit more details, but i have to admit, i never really understood *why* it's needed for covering...

Dieter


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