Multiple indexes

Multiple Recoll indexes can be created by using several configuration directories which are typically set to index different areas of the file system.

A specific index can be selected by setting the RECOLL_CONFDIR environment variable or giving the -c option to recoll and recollindex.

The recollindex program, used for creating or updating indexes, always works on a single index. The different configurations are entirely independant (no parameters are ever shared between configurations when indexing).

All the search interfaces (recoll, recollq, the Python API, etc.) operate with a main configuration, from which both configuration and index data are used, and can also query data from multiple additional indexes. Only the index data from the latter is used, their configuration parameters are ignored. This implies that some parameters should be consistent among index configurations which are to be used together.

When searching, the current main index (defined by RECOLL_CONFDIR or -c) is always active. If this is undesirable, you can set up your base configuration to index an empty directory.

Index configuration parameters can be set either by using a text editor on the files, or, for most parameters, by using the recoll index configuration GUI. In the latter case, the configuration directory for which parameters are modified is the one which was selected by RECOLL_CONFDIR or the -c parameter, and there is no way to switch configurations within the GUI.

See the configuration section for a detailed description of the parameters

Some configuration parameters must be consistent among a set of multiple indexes used together for searches. Most importantly, all indexes to be queried concurrently must have the same option concerning character case and diacritics stripping, but there are other constraints. Most of the relevant parameters affect the term generation.

Using multiple configurations implies a small level of command line or file manager usage. The user must explicitely create additional configuration directories, the GUI will not do it. This is to avoid mistakenly creating additional directories when an argument is mistyped. Also, the GUI or the indexer must be launched with a specific option or environment to work on the right configuration.

In practise: creating and using an additional index

Initially creating the configuration and index:

mkdir /path/to/my/new/config

Configuring the new index can be done from the recoll GUI, launched from the command line to pass the -c option (you could create a desktop file to do it for you), and then using the GUI index configuration tool to set up the index.

recoll -c /path/to/my/new/config

Alternatively, you can just start a text editor on the main configuration file:

someEditor /path/to/my/new/config/recoll.conf

Creating and updating the index can be done from the command line:

recollindex -c /path/to/my/new/config

or from the File menu of a GUI launched with the same option (recoll, see above).

The same GUI would also let you set up batch indexing for the new index. Real time indexing can only be set up from the GUI for the default index (the menu entry will be inactive if the GUI was started with a non-default -c option).

The new index can be queried alone with

recoll -c /path/to/my/new/config

Or, in parallel with the default index, by starting recoll without a -c option, and using the PreferencesExternal Index Dialog menu.