Advanced query parameters

Alternative queries are used when the query parameter is either blank or not specified. Solarium by default sets the query parameter as *:*. Alternative queries can be used to get all documents from an index for faceting purposes.

$dismax->setQueryAlternative('*:*');

For selecting all documents in DisMax/eDisMax, the normal query syntax *:* does not work. To select all documents, set the default query value in Solarium query to empty string. This is required as the default query in Solarium is *:*. Also set the alternative query to *:*. DisMax/eDisMax normal query syntax does not support *:*, but the alternative query syntax does.