Question

I am planning to implement database search through a website – I know there is full-text search offered by mysql, but turns out that it is not supported for innodb engine (which I need for transaction support).
Other options are using sphinx or similar indexing applications. However they require some re factoring of the database structure and may take more time to implement than I have.

So what I decided on was to take each table and concatenate all its relevant columns into a newly added QUERY column. This query column should also recruit from column of other relevant tables.

This accomplished, I will use the ‘like’ clause on query column of the table to be searched to search to return results of specific domains (group of related tables).

Since my database is not expected to be too huge (< 1mn rows in the biggest table), I am expecting reasonable query times.

Does any one agree with this method or have a better idea?

Answer 1

You will not be happy with the solution of using LIKE with wildcards. It performs hundreds or thousands of times slower than using a fulltext search technology.

See my presentation Practical Full-Text Search in MySQL.

Instead of copying the values into a QUERY column, I would recommend copying the values into a MyISAM table where you have a FULLTEXT index defined. You could use triggers to do this.

You don’t need to concatenate the values together, you just need the primary key column and each of your searchable text columns.

CREATE TABLE OriginalTable (
  original_id SERIAL PRIMARY KEY,
  author_id INT,
  author_date DATETIME,
  summary TEXT,
  body TEXT
) ENGINE=InnoDB;

CREATE TABLE SearchTable (
  original_id BIGINT UNSIGNED PRIMARY KEY, -- not auto-increment
  -- author_id INT,
  -- author_date DATETIME,
  summary TEXT,
  body TEXT,
  FULLTEXT KEY (summary, body)
) ENGINE=MyISAM;