Secondary indexes in SQL Server.

  • Hi all,

    What are secondary indexes in SQL Server and why are they needed.

  • No such thing as a secondary index. Do you mean a secondary XML index?

    Gail Shaw
    Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
    SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability

    We walk in the dark places no others will enter
    We stand on the bridge and no one may pass
  • I can only imagine a writer using the term "secondary indexes" to refer to any indexes other than one on a Primary Key? In that case, such indexes are used to aid or make more efficient the retrieval of data.

  • OTF (1/21/2013)


    I can only imagine a writer using the term "secondary indexes" to refer to any indexes other than one on a Primary Key?

    That would be an incorrect term for them. The only 'secondary' indexes in SQL are secondary XML indexes. Indexes other than the primary key are just clustered/nonclustered indexes.

    Gail Shaw
    Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
    SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability

    We walk in the dark places no others will enter
    We stand on the bridge and no one may pass
  • That would be an incorrect term for them.

    Nevertheless, it's a term I've seen used by some authors to explain the concepts of Indexes.

    I guess only the OP knows whether the term was used as it relates to XML Indexes or Indexes in general.

  • OTF (1/21/2013)


    That would be an incorrect term for them.

    Nevertheless, it's a term I've seen used by some authors to explain the concepts of Indexes.

    I guess only the OP knows whether the term was used as it relates to XML Indexes or Indexes in general.

    It's common and correct for Oracle users to speak that way about indexes, maybe other DBMS' too, but not for SQL Server users. I would hope that an author writing about SQL Server whose work passed through a technical editor did not publish anything discussing "secondary indexes."

    There are no special teachers of virtue, because virtue is taught by the whole community.
    --Plato

  • Hello,

    There's good information on indexes on the MSDN website. Should give you the required background information:-

    http://msdn.microsoft.com/en-us/library/ms189271(v=sql.105).aspx

    Regards,

    Andrew

Viewing 7 posts - 1 through 6 (of 6 total)

You must be logged in to reply to this topic. Login to reply