Or FieldValueFilter - that's probably easier to use. > -----Original Message----- > From: Michael McCandless [mailto:luc...@mikemccandless.com] > Sent: Monday, November 04, 2013 4:37 AM > To: Lucene Users > Subject: Re: Lucene Empty Non-empty Fields > > You can also use FieldCache.getDocsWithField? > > Mike McCandless > > http://blog.mikemccandless.com > > > On Mon, Nov 4, 2013 at 7:33 AM, manoj raj <manojluc...@gmail.com> wrote: > > I did some experiments for finding empty fields, But i want to know > > whether there is any other better method. Have to reduce hard disk space. > > > > > > Method 1: Add "NULL String" in empty fields > > > > We can search with null string for empty column & non empty column > > > > > > Observations: > > > > - Index size will grow. > > - Suppose if we add one new column, then old documents will not have > > null string for that new column in index. > > - While fetching results, more IO will happen because of null string. > > > > > > Method 2: Add one extra field namely NON_EMPTY_COLUMN and add all not > > empty column names in that. > > We can search like NON_EMPTY_COLUMN:Field_Name, for empty column > > documents we have to search with Not of field name > > > > Observations: > > > > - Again Index size will grow > > - Fetching is not costly > > > > > > Method 3: While Searching, iterate through results and check for empty > > column by using doc.get > > > > Observations: > > > > - Iterations will become costly, suppose required results is not present > > in first set of results. > > - Also IO big impact in this. > > --------------------------------------------------------------------- > To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org > For additional commands, e-mail: java-user-h...@lucene.apache.org
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