Configurations, multiple indexes

Recoll supports defining multiple indexes, each defined by its own configuration directory, in which several configuration files describe what should be indexed and how.

When recoll or recollindex is first executed, it creates a default configuration directory. This configuration is the one used for indexing and querying when no specific configuration is specified. It is located in $HOME/.recoll/ for Unix-like systems and %LOCALAPPDATA% on Windows (typically C:\Users\[me]\Appdata\Local).

All configuration parameters have defaults, defined in system-wide files. Without further customisation, the default configuration will process your complete home directory, with a reasonable set of defaults. It can be changed to process a different area of the file system, select files in different ways, and many other things.

In some cases, it may be useful to create additional configuration directories, for example, to separate personal and shared indexes, or to take advantage of the organization of your data to improve search precision.

A plausible usage scenario for the multiple index feature would be for a system administrator to set up a central index for shared data, that you choose to search or not in addition to your personal data. Of course, there are other possibilities. for example, there are many cases where you know the subset of files that should be searched, and where narrowing the search can improve the results. You can achieve approximately the same effect with the directory filter in advanced search, but multiple indexes may have better performance and may be worth the trouble in some cases.

A more advanced use case would be to use multiple index to improve indexing performance, by updating several indexes in parallel (using multiple CPU cores and disks, or possibly several machines), and then merging them, or querying them in parallel.

See the section about configuring multiple indexes for more detail