indexed field property

K

Kevin

The Indexed field property offers 3 options:
No
Yes (Duplicates OK)
Yes (No Duplicates)

Is there a "rule-of-thumb" for which property to choose as they relate to
primary key fields? To me "No" and "Yes (Duplicates OK)" wouldn't be much
different. What is the benefit of Indexing a field when duplicates are OK?
Thanks in advance for your thoughts!
 
J

jahoobob via AccessMonster.com

From Access Help:
An index helps Microsoft Access find and sort records faster. Access uses
indexes in a table as you use an index in a book: to find data, it looks up
the location of the data in the index.
So No and Yes (Duplicates OK) are very different but a Primary key should not
allow duplicates as it is the unique identifier of a record.
A primary key would be something like an employee ID number which would be
unique (No Duplicates) to one person but you may have more (Duplicates OK)
than one person with the same date of hire but want to sort or find dates
 
J

jahoobob via AccessMonster.com

You can see the advantage of indexing by sortin a fairly large table on a
field that is not indexed and then indexing it and sorting again. You will
notice a that Access takes some time after you index when you close the
table in design view while it creates the index but each successive sort is
faster.
when you sort on an unindexed field it is akin to indexing everytime you do
it.
So, there is a big difference between No and Yes (Duplicates OK)
From Access Help:
An index helps Microsoft Access find and sort records faster. Access uses
indexes in a table as you use an index in a book: to find data, it looks up
the location of the data in the index.
So No and Yes (Duplicates OK) are very different but a Primary key should not
allow duplicates as it is the unique identifier of a record.
A primary key would be something like an employee ID number which would be
unique (No Duplicates) to one person but you may have more (Duplicates OK)
than one person with the same date of hire but want to sort or find dates
The Indexed field property offers 3 options:
No
[quoted text clipped - 5 lines]
different. What is the benefit of Indexing a field when duplicates are OK?
Thanks in advance for your thoughts!
 
K

Kevin

Great feedback! Thank you very much!

jahoobob via AccessMonster.com said:
You can see the advantage of indexing by sortin a fairly large table on a
field that is not indexed and then indexing it and sorting again. You will
notice a that Access takes some time after you index when you close the
table in design view while it creates the index but each successive sort is
faster.
when you sort on an unindexed field it is akin to indexing everytime you do
it.
So, there is a big difference between No and Yes (Duplicates OK)
From Access Help:
An index helps Microsoft Access find and sort records faster. Access uses
indexes in a table as you use an index in a book: to find data, it looks up
the location of the data in the index.
So No and Yes (Duplicates OK) are very different but a Primary key should not
allow duplicates as it is the unique identifier of a record.
A primary key would be something like an employee ID number which would be
unique (No Duplicates) to one person but you may have more (Duplicates OK)
than one person with the same date of hire but want to sort or find dates
The Indexed field property offers 3 options:
No
[quoted text clipped - 5 lines]
different. What is the benefit of Indexing a field when duplicates are OK?
Thanks in advance for your thoughts!
 

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