Chaining Indexes

With ISYS you can create as many indexes as you like. You may prefer one large index that contains all the files, emails, database entries and other documents that you want to search across, but there are advantages to breaking it down into smaller ‘chunks’. These benefits include :

• Updates will be much quicker (although the total time may be longer)

• When you run a query on a chained index, it queries all of the indexes in the chain’s list

• Searches can be made on one or more specific indexes to restrict the results returned

• Indexes can be distributed (e.g., to other offices), with incremental revisions distributed later and ‘chained’ on

• Corruption in one index will not affect searches on other indexes

There are two types of chains: dynamic and static chains.

A Dynamic chain is very simple to make; just click the ‘Open an ISYS Index’ button on the toolbar
(or File > Open an ISYS Index from the menu). Then perform a multi-select by holding down the Ctrl key and clicking all the indexes you want to search. Click OK and then perform your query.

A Static chain is really just a list that links multiple indexes together. When you query the chained index, it searches all the indexes that are listed within it.

To set it up, open ISYS Utilities and go Tools > Multiple index action.

Select the ninth option which is to Create a static chain. You will then be asked to select the indexes that will make up the chain. Click on the ‘Select’ button and perform a multi-select on all the indexes you want to search. Click OK. Click Next.

You will need to give the chain a name and choose the path on where it will be saved. Once this is done, click Next. You will be presented with a Confirmation screen. If all the details are correct, click Finish.

Display results

Your results can come from any of the indexes included in the chain. The list of words found (on the right of the Query window) might show multiples of the same word (once for each index which contains it).

Other points to know:

• Each chain can contain links to 32 indexes.

• A static chain can contain other chained indexes, giving you chains of chains.

• All indexes must have been created with the same version of ISYS.

• Static chains are searched in the order in which they are listed in the ISYS.CFG file.

• The paths specified must be available from all machines that will access them.

• Static chains can be used in ISYS:desktop and ISYS:web.

Don’t forget, if you have any questions regarding Tech Tips you can e-mail support@isys-search.com