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Lucy::Index::DeletionsWriter – Apache Lucy Documentation
Apache Lucy™

NAME

Lucy::Index::DeletionsWriter - Abstract base class for marking documents as deleted.

SYNOPSIS

my $polyreader  = $del_writer->get_polyreader;
my $seg_readers = $polyreader->seg_readers;
for my $seg_reader (@$seg_readers) {
    my $count = $del_writer->seg_del_count( $seg_reader->get_seg_name );
    ...
}

DESCRIPTION

Subclasses of DeletionsWriter provide a low-level mechanism for declaring a document deleted from an index.

Because files in an index are never modified, and because it is not practical to delete entire segments, a DeletionsWriter does not actually remove documents from the index. Instead, it communicates to a search-time companion DeletionsReader which documents are deleted in such a way that it can create a Matcher iterator.

Documents are truly deleted only when the segments which contain them are merged into new ones.

ABSTRACT METHODS

delete_by_term

$deletions_writer->delete_by_term(
    field => $field  # required
    term  => $term   # required
);

Delete all documents in the index that index the supplied term.

  • field - The name of an indexed field. (If it is not spec’d as indexed, an error will occur.)
  • term - The term which identifies docs to be marked as deleted. If field is associated with an Analyzer, term will be processed automatically (so don’t pre-process it yourself).

delete_by_query

$deletions_writer->delete_by_query($query);

Delete all documents in the index that match query.

updated

my $bool = $deletions_writer->updated();

Returns true if there are updates that need to be written.

seg_del_count

my $int = $deletions_writer->seg_del_count($seg_name);

Return the number of deletions for a given segment.

  • seg_name - The name of the segment.

INHERITANCE

Lucy::Index::DeletionsWriter isa Lucy::Index::DataWriter isa Clownfish::Obj.