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From: Anton Shepelev <anton.txt@g{oogle}mail.com>
Newsgroups: comp.databases.ms-sqlserver
Subject: No covering indices for table types?
Date: Fri, 12 Jul 2024 15:15:01 +0300
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Hello, all.

I wanted to create a convenient table-type for storing time
series (with possibly non-uniqe sample marks):

  CREATE TYPE series_t AS TABLE
  (  moment DATETIME NOT NULL,
     value  FLOAT
  )

For efficient querying and joining, I need a covering index
on the [moment] field that includes [value], but the INCLUDE
keyword does not seem to be suported:

  https://learn.microsoft.com/en-us/sql/t-sql/statements/create-type-transact-sql

so that I can only create a simple non-convering column
index:

  CREATE TYPE series_t AS TABLE
  (  moment DATETIME NOT NULL INDEX moment,
     value  FLOAT
  )

or a compound table index for both columns:

  CREATE TYPE series_t AS TABLE
  (  moment DATETIME NOT NULL,
     value  FLOAT
     INDEX Main(moment, value)
  )

What is best practice in cases when a covering index is
required for a tale-type?

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