full-text-indexing

I have a simple query that relies on two full-text indexed tables, but it runs extremely slow when I have the CONTAINS combined with any additional OR search. As seen in the execution plan, the two full text searches crush the performance. If I query with just 1 of the CONTAINS, or neither, the query is sub-second, but the moment you add OR into the mix the query becomes ill-fated. The two tables are nothing special, they're not overly wide (42 cols in one, 21 in the other; maybe 10 cols are FT indexed in each) or even contain very many records (36k recs in the biggest of the two). I was able

I have a query with a number of test fields something like this: SELECT * FROM some-table WHERE field1 ILIKE "%thing%" OR field2 ILIKE "%thing" OR field3 ILIKE "%thing"; The columns are pretty much all varchar(50) or thereabouts. Now I understand to improve performance I should index the fields upon which the search operates. Should I be considering replacing ILIKE with TSEARCH completely? A full text search setup is not identical to a "contains" like query. It stems words etc so you can match "cars" against "car". If you really want a fast ILIKE then no standard database index or FTS will

I would like to get some frequently occurring phrases with Lucene. I am getting some information from TXT files, and I am losing a lot of context for not having information for phrases e.g. "information retrieval" is indexed as two separate words. What is the way to get the phrases like this? I can not find anything useful on internet, all the advices, links, hints especially examples are appreciated! EDIT: I store my documents just by title and content: Document doc = new Document(); doc.add(new Field("name", f.getName(), Field.Store.YES, Field.Index.NOT_ANALYZED)); doc.add(new Field("text",

I've created an Oracle Text index like the following: create index my_idx on my_table (text) indextype is ctxsys.context; And I can then do the following: select * from my_table where contains(text, '%blah%') > 0; But lets say we have a have another column in this table, say group_id , and I wanted to do the following query instead: select * from my_table where contains(text, '%blah%') > 0 and group_id = 43; With the above index, Oracle will have to search for all items that contain 'blah' , and then check all of their group_id s. Ideally, I'd prefer to only search the items with group_id = 43

Is there a way of keeping the index in RAM instead of keeping it on the hard disk? We want to make searching faster. Narayan Is there a way of keeping the index in RAM instead of keeping it on the hard disk? Using the RAMDirectory class SampleUsage here Also from the Lucene FAQs ImproveSearchingSpeed Generally for faster indexing performance it's best to flush by RAM usage instead of document count and use as large a RAM buffer as you can. Also check this question: EDIT: RE: RamDirectory , As the API says RamDirectory is A memory-resident Directory implementation. , it keeps only those index

This question already has an answer here: Can't find FULLTEXT index matching the column list (indexes is set) 3 answers Iam trying to execute this query in my xampp, but it is not turning up. SELECT pid,description,alttext FROM wp_ngg_pictures WHERE MATCH (description, filename, alttext) AGAINST ('*image2*' IN BOOLEAN MODE) AND exclude != 1 it has returned this error #1191 - Can't find FULLTEXT index matching the column list. can any one help me plz Manju ALTER TABLE table ADD FULLTEXT index_name(column1); Try the above query to add full text index to the columns. 来源： https://stackoverflow.com

I am trying to create FULL TEXT index using Entity Framework Migration by executing custom Sql. My migration class looks like this: public partial class DocumentContentFullTextIndex : DbMigration { public override void Up() { AlterColumn("dbo.Attachments", "ContentType", c => c.String(maxLength: 260)); Sql("CREATE FULLTEXT CATALOG FullTextIndexes AS DEFAULT;", true); Sql(@"CREATE FULLTEXT INDEX ON [Attachments]( Content TYPE COLUMN ContentType Language 'ENGLISH' ) KEY INDEX [PK_dbo.Attachments] ON FullTextIndexes;", true); } public override void Down() { AlterColumn("dbo.Attachments",