Tag is a special character string parameter which can be assigned to a set of documents to group them into a logical subsection of the search database. At search time you can specify a tag value to limit searches to only a desired group. You can also pass the tag limit to indexer to have it re-crawl only the given group of the documents, or perform any other actions on the group, like watching statistics for the group, deleting the documents belonging to the group and so on.
Use the Tag command in indexer.conf to assign a tag value to a site, a site part, or a group of sites. For example:
Tag cars Server http://www.ford.com/ Server http://www.toyota.com/ Tag computers Server http://www.sun.com/ Server http://www.apple.com/
When sending a search query, you can specify a tag value
to limit searches to the desired subsection of the database
with help of the
You may find useful to add a SELECT
search form variable into the search form
Search through: <SELECT NAME="t"> <OPTION VALUE="">All sites</OPTION> <OPTION VALUE="cars">Cars</OPTION> <OPTION VALUE="computers">Computers</OPTION> </SELECT>Take a look into Tag, indexer.conf-dist and search.htm-dist for more details and examples.
Starting from the version 3.1.x, tags are stored in the database as character strings and support patterns with help of SQL LIKE operator with _ and % wildcards and thus support substring searches on tags.
Nested tagsSQL LIKE patterns also make possible to have nested tag. For example, the documents with the tag value computers-hardware can be found using any of the following tag patters: computers-%, computers-hardware, %-hardware.
Playing with LIKE wildcards you can make a document match multiple tag selections. For example, the tag ABCDE will match all of the following patterns:
_BCDE A_CDE AB_DE ABC_E ABCD_
To limit an indexer action to a
desired tag use the
-t command line option.
indexer -t cars -Swill display statistics for the documents associated with the tag cars.
You can also
-t options. For example:
indexer -t cars -t computers -amwill mark all documents from the tags cars and computers as expired and will re-crawl to these documents forcing full update information about the documents.
-t command line option also understands
SQL LIKE patterns.
indexer -t "c%" -Cwill delete information about all documents associated with any tag starting with the letter c from the search database.