I was just reading that yesterday. What does that exactly mean "indexed".
Once again, I am a self taught user, and while I am fairly computer savey, I
am no professional. Right now all of my tables have a primary key that is
indexed, is that all I am looking for?
Not really!
An "Index" is a datastructure within a database which Access uses to make
finding and sorting records faster. A Primary Key is one type of index; if you
use the Relationships window to define a relationship between two tables,
Access creates another Index on the joining field in the "many" side table.
You can also select any field (except for Memo or OLE fields) in a table and
use the field properties window on the lower left of the screen to create an
Index. This can be "unique" (if you want the field to be restricted so that no
value in it ever occurs twice) or not as appropriate.
You can also use the Indexes tool - looks like lightening hitting a datasheet
- to create indexes, either on single fields, or a single index covering
multiple fields.
Indexes make it faster to retrieve records by searching, and make sorting
records on the indexed field faster. They can also enforce uniqueness and are
used in joined-table queries (hence their automatic creation).
The downside is that though they make data retrieval faster, they can make
data updating slower (Access must populate both the table and the index when
you add or edit a record). They also make the database larger, and there is a
limit of 32 indexes on any one table. It can be sort of a black art to
determine which fields should be indexed and when the index should be omitted,
but proper indexing is very important to a well designed database; as a rule
of thumb, fields that you'll routinely use for searching and sorting should be
indexed - e.g. you might want a three-field index on LastName, FirstName and
MiddleName if you'll usually be sorting names in that order; or separate
indexes on LastName and FirstName if you'll often be sorting or searching on
either name.