Indexes During a sorted index build, the page cleaner thread is signaled periodically to flush dirty pages to ensure that the checkpoint operation can be processed quickly. Normally, the page cleaner thread flushes dirty pages when the number of clean pages falls below a set threshold. For sorted index builds, dirty pages are flushed promptly to reduce checkpoint overhead and to parallelize I/O and CPU activity. Sorted index builds may result in optimizer statistics that differ from those generated by the previous method of index creation. The difference in statistics, which is not expected to affect workload performance, is due to the different algorithm used to populate the index. Full-text indexes are created on text-based columns ( CHAR ,  VARCHAR , or  TEXT  columns) to speed up queries and DML operations on data contained within those columns. A full-text index is defined as part of a  CREATE TABLE  statement or added to an existing table using ALTER TABLE  or  CREATE INDEX . Full-text search is performed using  MATCH() ... AGAINST  syntax. For usage information, see Section 12.10, “Full-Text Search Functions” . InnoDB  full-text indexes are described under the following topics in this section: InnoDB  full-text indexes have an inverted index design. Inverted indexes store a list of words, and for each word, a list of documents that the word appears in. To support proximity search, position information for each word is also stored, as a byte offset. When an  InnoDB  full-text index is created, a set of index tables is created, as shown in the following example: 3044 mysql>  CREATE TABLE opening_lines ( id INT UNSIGNED AUTO_INCREMENT NOT NULL PRIMARY KEY, opening_line TEXT(500), author VARCHAR(200), title VARCHAR(200), FULLTEXT idx (opening_line) ) ENGINE=InnoDB; mysql>  SELECT table_id, name, space from INFORMATION_SCHEMA.INNODB_TABLES Sorted Index Builds and Optimizer Statistics 15.6.2.4 InnoDB Full-Text Indexes InnoDB Full-Text Index Design InnoDB Full-Text Index Tables •InnoDB Full-Text Index Design •InnoDB Full-Text Index Tables •InnoDB Full-Text Index Cache •InnoDB Full-Text Index DOC_ID and FTS_DOC_ID Column •InnoDB Full-Text Index Deletion Handling •InnoDB Full-Text Index Transaction Handling •Monitoring InnoDB Full-Text Indexes