Indexing for Combo Boxes

Indexing for Combo Boxes

Post by Neil Ginsber » Sat, 23 Jun 2001 05:23:13



A couple of questions about indexes with a SQL Server back end and an Access
mdb front end.

1) If a combo box has two columns, one for the primary key of the list
table, and another for another field, such as Description, is a two-field
index needed, or is an index on the primary key enough?

2) Similarly, if a combo box has three columns, one for primary key, along
with two additional ones, and the primary key column is hidden, resulting in
the user entering a value based on the second column, what sort of index
would be useful -- an index based on the second column alone, second and
third, other?

Thanks!

Neil

 
 
 

Indexing for Combo Boxes

Post by Michel Wals » Sat, 23 Jun 2001 21:50:58


Hi,

Probably irrelevant, since the data has already be pumped from the server,
being actually present in the front end application, held in the control.

If the rowSource is  "SELECT F1, F2, F3 FROM somewhere WHERE F4=something"

then, maybe, an index on F4 will be useful. It is unlikely, in general, that
data is send to the server when the end user simply "choose" an item in the
combo box of the form, only when the record is tentatively saved.

Vanderghast, Access MVP


Quote:> A couple of questions about indexes with a SQL Server back end and an
Access
> mdb front end.

> 1) If a combo box has two columns, one for the primary key of the list
> table, and another for another field, such as Description, is a two-field
> index needed, or is an index on the primary key enough?

> 2) Similarly, if a combo box has three columns, one for primary key, along
> with two additional ones, and the primary key column is hidden, resulting
in
> the user entering a value based on the second column, what sort of index
> would be useful -- an index based on the second column alone, second and
> third, other?

> Thanks!

> Neil


 
 
 

Indexing for Combo Boxes

Post by Mary Chipma » Sat, 23 Jun 2001 22:23:20


If the combo box is simply displaying non-key values, then no index is
needed on the other columns. There already is an index on the PK. Take
a look at the Index Tuning Wizard to help you make indexing decisions.

-- Mary
Microsoft Access Developer's Guide to SQL Server
http://www.amazon.com/exec/obidos/ASIN/0672319446

On Thu, 21 Jun 2001 15:23:13 -0500, "Neil Ginsberg"


>A couple of questions about indexes with a SQL Server back end and an Access
>mdb front end.

>1) If a combo box has two columns, one for the primary key of the list
>table, and another for another field, such as Description, is a two-field
>index needed, or is an index on the primary key enough?

>2) Similarly, if a combo box has three columns, one for primary key, along
>with two additional ones, and the primary key column is hidden, resulting in
>the user entering a value based on the second column, what sort of index
>would be useful -- an index based on the second column alone, second and
>third, other?

>Thanks!

>Neil

 
 
 

1. pls help : COMBO box or list box

hi there
i would apprieciate some help please, my problems are
1. i have a database from which i would like to chose a certain record
of a field, these recs should automatically be displayed in an combo
or list box. how do i do this

2. what should i use are combo or a list box, and what difference will
either make?

tia
Thanks In Advance From..
Irfaan Hamid
Kuala Lumpur,
Malaysia.

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