NAME

Search::Xapian::WritableDatabase - writable database object

DESCRIPTION

This class represents a Xapian database for indexing. It's a subclass of Search::Xapian::Database, which is used for searching.

METHODS

new <database> or new <path> <mode>

Class constructor. Takes either a database object, or a path and one of DB_OPEN, DB_CREATE, DB_CREATE_OR_OPEN or DB_CREATE_OR_OVERWRITE. These are exported by Search::Xapian with the 'db' option.

clone

Return a clone of this class.

flush

Flush to disk any modifications made to the database.

For efficiency reasons, when performing multiple updates to a database it is best (indeed, almost essential) to make as many modifications as memory will permit in a single pass through the database. To ensure this, Xapian batches up modifications.

Flush may be called at any time to ensure that the modifications which have been made are written to disk: if the flush succeeds, all the preceding modifications will have been written to disk.

If any of the modifications fail, an exception will be thrown and the database will be left in a state in which each separate addition, replacement or deletion operation has either been fully performed or not performed at all: it is then up to the application to work out which operations need to be repeated.

Beware of calling flush too frequently: this will have a severe performance cost.

Note that flush need not be called explicitly: it will be called automatically when the database is closed, or when a sufficient number of modifications have been made.

add_document <document>

Add a new document to the database.

This method adds the specified document to the database, returning a newly allocated document ID.

Note that this does not mean the document will immediately appear in the database; see flush() for more details.

As with all database modification operations, the effect is atomic: the document will either be fully added, or the document fails to be added and an exception is thrown (possibly at a later time when flush is called or the database is closed).

delete_document <doc_id>

Delete a document from the database. This method removes the document with the specified document ID from the database.

Note that this does not mean the document will immediately disappear from the database; see flush() for more details.

As with all database modification operations, the effect is atomic: the document will either be fully removed, or the document fails to be removed and an exception is thrown (possibly at a later time when flush is called or the database is closed).

delete_document_by_term <term>

Delete any documents indexed by a term from the database. This method removes any documents indexed by the specified term from the database.

The intended use is to allow UIDs from another system to easily be mapped to terms in Xapian, although this method probably has other uses.

replace_document <doc_id> <document>

eplace a given document in the database.

This method replaces the document with the specified document ID. Note that this does not mean the document will immediately change in the database; see flush() for more details.

As with all database modification operations, the effect is atomic: the document will either be fully replaced, or the document fails to be replaced and an exception is thrown (possibly at a later time when flush is called or the database is closed).

replace_document_by_term <unique_term> <document>

Replace any documents matching an unique term.

This method replaces any documents indexed by the specified term with the specified document. If any documents are indexed by the term, the lowest document ID will be used for the document, otherwise a new document ID will be generated as for add_document.

The intended use is to allow UIDs from another system to easily be mapped to terms in Xapian, although this method probably has other uses.

Note that this does not mean the document(s) will immediately change in the database; see flush() for more details.

As with all database modification operations, the effect is atomic: the document(s) will either be fully replaced, or the document(s) fail to be replaced and an exception is thrown (possibly at a later time when flush is called or the database is closed).

reopen

Re-open the database. makes sure you have a fresh db handle.

SEE ALSO

Search::Xapian,Search::Xapian::Enquire,Search::Xapian::Database