In the worst case, the LIKE pattern will have leading wildcards requiring each index key to be checked. If the column is indexed, matching can be done against the index keys, but with much less efficient than most index searches. If you apply it to a non-indexed column, the database will use a full scan to find matches. However, the MySQL LIKE statement may not be useful in some circumstances. This means that LIKE is 100% accurate when searching for a phrase. A high recall rate means fewer relevant results are overlooked. High LIKE operator precision means that fewer false results are displayed. Thus, you can easily understand the intricacies of the work of each method. I'll talk about this in the next subsection.Ī synonym for the LIKE operator is precision, for full-text input it is flexibility. But the LIKE operator alone is not as useful as FTS. The relevance value is a non-negative floating-point number.įull-Text Search is not a complex tool, it is almost as simple as the LIKE operator. When you use the MATCH () command in a WHERE clause, the result column rows are automatically sorted by relevance. Relevance value is how similar the search string and the text in the string are.Įnter fullscreen mode Exit fullscreen mode The MATCH () command returns the relevance value for each row in a column. The search string is specified with an argument in the AGAINST () expression. By content I mean the combination of one or more columns included in the FULLTEXT index. It compares a string to the text content. The MATCH () function executes a language search. That is why indexes are usually added later. Large amounts of data are loaded into the table much faster if no index is added. However, you should refrain from adding the FULLTEXT index right away when creating the table. You can also add indexes later using the ALTER TABLE or CREATE INDEX commands. When you create a table using the CREATE TABLE command, you can create these indexes on the VARCHAR and TEXT columns. InnoDB support has been added since version 5.6.4. Mysql supports full-text indexes on MyISAM tables. To use full-text search in MySQL you need to use full-text indexes and the MATCH () function.
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