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
