Searching the text of a collection of documents or free text fields in a database to find those containing a word or combination of words.

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12
votes
3answers
3k views

How is LIKE implemented?

Can anyone explain how the LIKE operator is implemented in current database systems (e.g. MySQL or Postgres)? or point me to some references that explain it? The naive approach would be to inspect ...
3
votes
1answer
5k views

Mysql fulltext search my.cnf optimization

I have open a question on http://serverfault.com/questions/353888/mysql-full-text-search-cause-high-usage-cpu Some user recommended asking here. We built a news site. Every day we will input tens of ...
5
votes
1answer
963 views

MySQL EXPLAIN doesn't show 'use index' for FULLTEXT

I have a basic table : create table fullTextTest ( id INT(11) NOT NULL, superText CHAR(255) NOT NULL, superLongText TEXT NOT NULL, primary key (`id`), FULLTEXT KEY `superText` ...
3
votes
1answer
1k views

FULLTEXT index ignored in BOOLEAN MODE with 'number of words' conditional

fulltext match is ignoring its index when I add a number of words conditional for its boolean mode. The selects are as follows: explain select * from seeds WHERE MATCH(text) AGAINST ("mount ...
6
votes
1answer
1k views

Can I have an InnoDB master and MyISAM slaves with Full-Text for searching?

I'd like to use InnoDB on the master, for its transactional ability, but MyISAM on the slaves for the full-text search ability. Is this possible?
6
votes
2answers
2k views

Why does MyISAM support FULLTEXT Searching and InnoDB does not?

I know the basic differences between the MyISAM and InnoDB engines. In MySQL 5.6 beta, InnoDB will support fulltext search. But, I wonder why previous versions of InnobDB didn't support FTS? My guess ...
1
vote
1answer
246 views

MySQL FullText search on string shorter than 3 chars returns no rows

I have a MySQL table with some addresses in it. Let's say I have the following 2 rows: "10 Fake Street" "101 Fake Street" I'm trying to use fulltext search with MATCH() AGAINST(). I have set ...
0
votes
1answer
752 views

PostgreSQL FTS and Trigram-similarity Query Optimization

I have recently started working on PostgreSQL and I have around 12M rows to handle in which I want to apply Full Text Search. I don't have any prior experience in handling such databases. I have tried ...
3
votes
3answers
2k views

slow query with fulltext and left join

I have 3 tables about 250,000 records. table1 is MyISAM, add fullindex with title and content, add index with pid. table2 and table3 are InnoDB, add index with pid. Only query table3, just cost ...
30
votes
5answers
8k views

What database technologies do big search engines use? [closed]

Does anybody knows how Google or Yahoo perform searches for keywords against very very huge amounts of data? What sort of database or technologies do they employ for this? It takes few milliseconds, ...
5
votes
1answer
5k views

Why full-text-search returns less rows than LIKE

I don't get full-text-search working as I want it to, and I don't understand the differences in the resultlists. Example statements: SELECT `meldungstext` FROM `artikel` WHERE `meldungstext` LIKE ...
7
votes
3answers
485 views

Full text search results in a large amount of time spent in 'FULLTEXT initialization'

I'm currently trying to run some queries against a data dump of Stack Overflow's comments. Here's what the schema looks like: CREATE TABLE `socomments` ( `Id` int(11) NOT NULL, `PostId` int(11) ...
5
votes
1answer
301 views

MySQL fulltext selection performance

I have 1.5M rows in a table. Following is the table create code: CREATE TABLE `jobs` ( `id` INT(8) NOT NULL AUTO_INCREMENT, `job_id` VARCHAR(50) NOT NULL DEFAULT '', `title` VARCHAR(255) ...
12
votes
5answers
5k views

SQL Server 2008 Full Text Index Never Seems to Complete

Our website has a SQL Server 2008 R2 Express Edition database with full-text indexing for our website search. Each time a new record is added or updated in one of the indexed tables, the indexing ...
6
votes
2answers
2k views

Slow ORDER BY with LIMIT

I have this query: SELECT * FROM location WHERE to_tsvector('simple',unaccent2("city")) @@ to_tsquery('simple',unaccent2('wroclaw')) order by displaycount I'm happy with it: "Sort ...
4
votes
2answers
1k views

maintaining full text index on large table

I'm on SQL Server 2008 and have a table, for reporting purposes, with 500,000 records that will easily reach the millions. The table will employ a full text index for rapid searching on a handful of ...
4
votes
3answers
767 views

Full Text Search With PostgreSQL

i have a table with this rows: Stickers ------------------------------------------------------ ID | Title |Keywords (ts_vector) ------------------------------------------------------ ...
2
votes
2answers
718 views

MySQL Full Text index issue

I Have a table articles with following data mysql> select * from articles; +----+-----------------------+------------------------------------------+ | id | title | body ...
5
votes
1answer
12k views

Why is LIKE more than 4x faster than MATCH…AGAINST on a FULLTEXT index in MySQL?

I'm not getting this. I've got a table with these indexes PRIMARY post_id INDEX topic_id FULLTEXT post_text Table has (only) 346 000 rows. I am trying to perform 2 queries. SELECT ...
5
votes
2answers
15k views

Why does simple ALTER TABLE command take so long on table with full-text index?

I have a large (~67 million rows) name-value table that has full-text indexing on the value column (DataValue). My question is: If I try to run the following sql command: ALTER TABLE VisitorData ...
4
votes
2answers
7k views

How to set full text catalog location SQL Server 2008/2012

I want to upgrade my SQL Server 2005 database to SQL Server 2012. In SQL Server 2005 you can set the location of the full text catalog when you create it. But in SQL Server 2012 (and in SQL Server ...
3
votes
2answers
287 views

Slow fulltext search due to wildly innacurate row estimates

Fulltext queries against this database (storing RT tickets) seem to be taking a very long time to execute. The attachments table (containing the fulltext data) is about 15GB. The database schema is ...
3
votes
1answer
282 views

Can underscore be forced as a word splitter without a full-text parser plugin?

Is there any way in MySQL to force underscore to become a word splitter character (like space or dash) without having to use a fulltext parser plugin? If not, does such a plugin already exist or do I ...
3
votes
2answers
783 views

SQL Server 2005: Full-text search space requirements

Is there a way to calculate the physical drive space required for a full-text search catalog? Space is cheap, but I'd like to know what I'm getting into. I'm looking at a table of about 200 articles ...
2
votes
1answer
1k views

Reorganize full text catalog is offline or online?

I need to schedule a Full Text Search Maintenance and I was reading this link: http://msdn.microsoft.com/en-us/library/ms176095.aspx. Reading this documentation I am supposing that I need to ...
1
vote
1answer
45 views

Full text search on multiple joined tables

I'm trying to set up a full text search in PostgreSQL but coming across the problem that the more tables I join to the query the fewer the results I get back. The tables I am trying to join are: ...
1
vote
1answer
346 views

MySQL FULLTEXT search not returning any results

I'm wondering why my fulltext search isn't returning any results. To me this seems pretty straightforward, but alas it's not working. I'm far from a DBA, but looking at the EXPLAINed query, I see ...
1
vote
2answers
137 views

Mysql might have too many indexes

I am using the php framework Laravel for my application, together with mysql 5.6, in order to have full-text search with innoBD. But I am not sure if I have too many indexes. My application allows ...
1
vote
2answers
212 views

Mysql fulltext index search returning weird result

I have ingredient table. I want all those recipes which have certain ingredients. Below is my table structure. Table(ingredient) - Applied fulltext index on ingredient column. ...
1
vote
1answer
124 views

“Wrong affix file formate for flag” while loading dictionaries from LibreOffice in PostgreSQL 9.3

Trying to get good TEXT SEARCH results out of PostgreSQL in English, German and Dutch made that I downloaded proofing tools of LibreOffice (tried of version 4.3 and 3.3) and iSpell. I placed the files ...
1
vote
1answer
2k views

Why does MATCH() give Score 0, if there are less rows in the database?

I followed this example from the Mysql Documentation: CREATE TABLE articles ( id INT UNSIGNED AUTO_INCREMENT NOT NULL PRIMARY KEY, title VARCHAR(200), body TEXT, FULLTEXT ...
0
votes
1answer
14 views

Full text search on two tsvector columns

I'm trying to do a full text search across two columns of two separate tables in PostgreSQL 9.4.2. The tables and columns are: article.article_title keyword.keyword Where there is a many-to-many ...
0
votes
1answer
59 views

Searching through lots of applications

Google search has instant search feature. While you are typing, it finds the pages. Apple.com search box. StackExchange ask question part finds similar questions while you are typing question title. ...