Contact Manager - Filtered Indexes

Databases get large. They get cumbersome. Rarely ever will you want to look at every record in your database. Most of the time you will want to break it down into smaller pieces so that it is easier to manage. You might need to look at all the records in a particular state, or a particular zip code, or any number of other categories. The means by which these records are grouped is called a Filter. Filters are very powerful tools. Without them, you would have to sort through every record in your database trying to find the records you want to look at. Filters do this for you. They look at every record in your database and see which ones meet the criteria you have set aside for a group. Sometimes however, it can take a little time to process that much information. After all you are looking analyzing every record in the database, even if you aren't looking at all of them.

The way a filter works is pretty simple. When you create a filter, you establish some criteria that determine what records you want to view. For example, state = "TX". The filter looks at the first record in the database and checks the state field to see if it equals "TX." If it does it includes that record in the filter. If it does not equal "TX," then it ignores the record and goes on to the next one and checks it. This process happens quite fast, but can still take anywhere from a few seconds to a couple of minutes, depending on the size of the database. Now, there's another factor here. Earlier, we referred to the "next record" in the database. What that record is can vary. What determines the "next record" is the Index.

The index is how your database will be sorted. If your index is on the state field, then all the records in your database will be organized alphabetically by state. Wouldn't it be great if you could combine a filter, with an index so that all your "TX" records were together and the program wouldn't have to look through the entire database in order to filter out only those records? Well you can. They are called Filtered Indexes.

Combining indexes with filters can dramatically improve the access time when using filters in the contact manager, or when generating reports and quick lists. It does this by grouping together the records that are going to be filtered. That way, when TeleMagic looks at the "next record" in the filter, they are already sorted. In our example of filtering on "TX," all the Texas records will be together. It includes all these records. When it gets to the "next record" that is not in the filter, it stops looking. That way it doesn't have to look at the entire database.

There are a couple of criteria for the filters that can be used in conjunction with an index. First, the filter must be a simple filter and second, the fields the filter is using must be on the same level you are indexing on. When you create an index, you will have an option to attach a filter to it. That list will show you which filters can be selected. You can also edit an existing index and attach a filter to it. For additional help on creating filters and filtered indexes, see your online documentation

-- End of FAQ #550

FAQ ID #550

Product Related: TeleMagic 4.x

Last Updated:
March 20, 2000