If you don't use index, order by or group by in a select statement
Axapta will issue an SQL statement with no ORDER BY clause. That means
that no specific ordering of returned rows is guaranteed.
Note that using index HINT only means that statement issued by Axapta
will contain a hint to the database query optimizer telling it to
ACCESS the table using the specified index. For simple queries this
will usually result in the query returning rows in the order specified
by the index. This behavior is, however, NOT guaranteed in general.
If a table has a clustered index the table data will be physically
organized on disk together with the index data. Queries accessing
table using clustered index will run faster, because when leaf of the
index is found all row data is there too so no additional lookup to
find the rest of the row data is necessary, as is the case with
ordinary indexes. So yes, index being a clustered index has nothing to
do with it being unique or not. The name "clustered index" is a bit of
a misnomer, since it applies to how table is organized on disk rather
then the index itseft (the technique is called "index organized table"
in Oracle, which is a better name imo).
--
wlewicki
--- In [email protected], "leganchris" <[EMAIL PROTECTED]>
wrote:
> If you use a select statement in SQL with no Index hint, group by, or
> order by; does the data get returned by the index definition?
> Also is a clustered / nonclustered index the same as unique / non
> unigue?
>
> I don't think they are, but I can only find documentation on the
> unique and nonunique types. I thought clustered / non clustered were
> used to speed up select statements.
>
> Thanks
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