-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Brion Vibber Sent: Thursday, March 7, 2013 9:59 PM To: Wikimedia developers Subject: Re: [Wikitech-l] Indexing non-text content in LuceneSearch
On Thu, Mar 7, 2013 at 11:45 AM, Daniel Kinzler <[email protected]> wrote: > 1) create a specialized XML dump that contains the text generated by > getTextForSearchIndex() instead of actual page content. That probably makes the most sense; alternately, make a dump that includes both "raw" data and "text for search". This also allows for indexing extra stuff for files -- such as extracted text from a PDF of DjVu or metadata from a JPEG -- if the dump process etc can produce appropriate indexable data. > However, that only works > if the dump is created using the PHP dumper. How are the regular dumps > currently generated on WMF infrastructure? Also, would be be feasible > to make an extra dump just for LuceneSearch (at least for wikidata.org)? The dumps are indeed created via MediaWiki. I think Ariel or someone can comment with more detail on how it currently runs, it's been a while since I was in the thick of it. > 2) We could re-implement the ContentHandler facility in Java, and > require extensions that define their own content types to provide a > Java based handler in addition to the PHP one. That seems like a > pretty massive undertaking of dubious value. But it would allow maximum > control over what is indexed how. Nooooo don't do it :) > 3) The indexer code (without plugins) should not know about Wikibase, > but it may have hard coded knowledge about JSON. It could have a > special indexing mode for JSON, in which the structure is deserialized > and traversed, and any values are added to the index (while the keys > used in the structure would be ignored). We may still be indexing > useless interna from the JSON, but at least there would be a lot fewer false > negatives. Indexing structured data could be awesome -- again I think of file metadata as well as wikidata-style stuff. But I'm not sure how easy that'll be. Should probably be in addition to the text indexing, rather than replacing. -- brion I agree with Brion. Here are my 5 shenekel's worth. To indexing non-mwdumps with LuceneSearch I would: 1. modify the demon to read the custom/dump format or update the xml dump to support json dump. 2. it uses the MWdumper codebase to do this now. 3. add a lucene analyzer to handle the new data type, say a json analyzer. 4. add a Lucenedoc per Json based Wikidata schema 5. update the queries parser to handle the new queries and the modified Lucene documents. 6. for bonus points modify spelling correction and write a wiki data ranking algoritm But this would only solve reading static dumps used to bootstrap the index, I would then have to Change how MWSearch periodically polls Brion's OAIRepository to pull in updated pages. I've been coding some analytics from MWDumps from WMF/Wikia Wikis for research project I can say this: 1. Most big dumps (e.g. historic) inherit the isses of wikitext namely unescaped tags and entities which crash modern XML java libraries - so escape your data and validate the xml! 2. The god old SAX code in the MWDumper still works fine - so use it. 3. Use lucene 2.4 with the deprecated old APIs 4. Ariel is doing a great job (e.g. the 7Z compression and the splitting of the dumps) but these are things MWdumper does not handle yet. Finally based on my work with i18n team, TranslateWiki search that indexing JSON data with Solar + Solarium requires no Search Engine coding at all. You define the document schema, and use solarium to push JSON and get results too. I could do a demo of how to do this at a coming Hakathon if there is any interest, however when I offered to replace LuceneSearch like this last October the idea was rejected out of hand. -- oren _______________________________________________ Wikitech-l mailing list [email protected] https://lists.wikimedia.org/mailman/listinfo/wikitech-l _______________________________________________ Wikitech-l mailing list [email protected] https://lists.wikimedia.org/mailman/listinfo/wikitech-l
