Nobody can answer that question, you have to test in your particular situation. Filters are very efficient to use once created, can be created once and used often, etc.
Adding a special value to stand for an empty field is conceptually simple, and queries are straight forward. Unless you can demonstrate that there are speed issues, which method you choose is largely a matter of taste. Spending valuable programming time improving query response time by 0.000001% is...er...less than a good expenditure of time. Best Erick On 7/24/07, testn <[EMAIL PROTECTED]> wrote:
Would it be more efficient to create an additional inverted field where I assign a value to that field only when the field I would like to search is NULL? daniel rosher wrote: > > Perhaps you can use a filter in the following way. > > -Create a filter (via QueryFilter) that would contain all document that > do not have null values for the field > -flip the bits of the filter so that it now contains documents that have > null values for a field > -Use the filter in conjunction with subsequent queries. > > This would also help with performance as filters are simply bitsets and > can cheaply be stored, generated once and used often. > > Dan > > On Mon, 2007-07-23 at 13:57 -0700, Jay Yu wrote: >> If you want performance, a better way might be to assign some special >> string/value (if it's easy to create) to the missing field of docs and >> index the field without tokenizing it. Then you may search for that >> special value to find the docs. >> >> Jay >> >> Les Fletcher wrote: >> > Does this particular range query have any significant performance >> issues? >> > >> > Les >> > >> > Erik Hatcher wrote: >> >> >> >> On Jul 23, 2007, at 11:32 AM, testn wrote: >> >>> Is it possible to search for the document that specified field >> >>> doesn't exist >> >>> or such field value is null? >> >> >> >> This is from Solr, so I'm not sure off the top of my head if this mojo >> >> applies by itself, but a search for -fieldname:[* TO *] will result in >> >> all documents that do not have the specified field. >> >> >> >> Erik >> >> >> >> >> >> --------------------------------------------------------------------- >> >> To unsubscribe, e-mail: [EMAIL PROTECTED] >> >> For additional commands, e-mail: [EMAIL PROTECTED] >> >> >> > >> > --------------------------------------------------------------------- >> > To unsubscribe, e-mail: [EMAIL PROTECTED] >> > For additional commands, e-mail: [EMAIL PROTECTED] >> >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: [EMAIL PROTECTED] >> For additional commands, e-mail: [EMAIL PROTECTED] >> >> >> >> <<This email has been scanned for virus and spam content>> > Daniel Rosher > Developer > > > d: 0207 3489 912 > t: 0870 2020 121 > f: 0870 2020 131 > m: > http://www.hotonline.com/ > > > > > > > - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - > - - - - - - - - - - - - - - - - - - > This message is sent in confidence for the addressee only. It may contain > privileged > information. The contents are not to be disclosed to anyone other than the > addressee. > Unauthorised recipients are requested to preserve this confidentiality and > to advise > us of any errors in transmission. Thank you. > > hotonline ltd is registered in England & Wales. Registered office: One > Canada Square, > Canary Wharf, London E14 5AP. Registered No: 1904765. > > > This message has been scanned for viruses by BlackSpider MailControl - > www.blackspider.com > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > > > -- View this message in context: http://www.nabble.com/Search-for-null-tf4130600.html#a11762894 Sent from the Lucene - Java Users mailing list archive at Nabble.com. --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
