FAQ - Databases
Can Daisy Change Data in a Database?
No!
Daisy has been designed this way, so that there is no way that an important database can be corrupted.
Remember that Daisy should always be run on a snapshot or copy of your data, as it locks other users from the database. Daisy applies the lock, as it looks at the whole database, and any chart would be invalid, if any data were to be changed.
How Can I Check the Right Database is Open?
The easiest way is to use Database Properties command in the File menu.
This will list all details of the open database, including all of the fields.
How Can I Make a Subset of the Current Database?
Most versions of Daisy can make a subset of the current database, using the Save command in the File menu.
Various subsets of the database can be chosen.
What Databases Can Daisy Access?
Daisy can access data from the following database and other programs directly.
What Databases does Daisy Prefer?
With complicated analyses the amount of time reading the database is much more significant than actually spent processing it.
For this reason, it is recommended that the large databases are copied to a comma-separated file or Microsoft Excel.
What is the Format of the Daisy Comma-Separated-File?
This is the standard input form for Daisy.
Take a look at the file, newmark.txt, on the directory where you installed Daisy. This is the file, that is used as input to the Newmarket Winners Example.
"Date","Time","Race","Race_Type","Dist",...
"April 14, 1992","14:00","Constant Security ...
"April 14, 1992","14:35","Stechworth Stakes","...
"April 14, 1992","15:10","Nell Gwyn Stakes",...
Note the field names in the first record in the file.
All files and databases created by Daisy have this format.
Note that the format has quotes everywhere. These can be eliminated, if the text does not contain a comma, but it is probably best to always use them. Note too, that newlines are allowed in the data.
Note that all of the files in the examples were produced by exporting the data from Microsoft Access.
What is the Largest Size of Database that Can be Mapped with Daisy?
The size of problem that can be handled by Daisy depends more on the number of nodes created, than the number of records in the database.
There are two basic limits. No database can contain more than 300 fields and Daisy cannot map a database to more than 30,000 nodes.
The maximum number of records depends more on your computer and the response that you find acceptable. A practical limit for a ten to twenty field database is probably about 100,000 records. However, on fast computers, numbers in excess of 1,000,000 records, can be mapped within a time frame of about two minutes.
Note that smaller versions of Daisy have limits to the number of records they can access in a Daisy Chart at any one time.