Rechercher dans le manuel MySQL
25.39.17 The INFORMATION_SCHEMA INNODB_FT_INDEX_CACHE Table
The INNODB_FT_INDEX_CACHE
table
provides token information about newly inserted rows in a
FULLTEXT
index. To avoid expensive index
reorganization during DML operations, the information about newly
indexed words is stored separately, and combined with the main
search index only when OPTIMIZE
TABLE
is run, when the server is shut down, or when the
cache size exceeds a limit defined by the
innodb_ft_cache_size
or
innodb_ft_total_cache_size
system
variable.
This table is empty initially. Before querying it, set the value
of the innodb_ft_aux_table
system
variable to the name (including the database name) of the table
that contains the FULLTEXT
index; for example
test/articles
.
For related usage information and examples, see Section 15.14.4, “InnoDB INFORMATION_SCHEMA FULLTEXT Index Tables”.
The INNODB_FT_INDEX_CACHE
table has
these columns:
WORD
A word extracted from the text of a newly inserted row.
FIRST_DOC_ID
The first document ID in which this word appears in the
FULLTEXT
index.LAST_DOC_ID
The last document ID in which this word appears in the
FULLTEXT
index.DOC_COUNT
The number of rows in which this word appears in the
FULLTEXT
index. The same word can occur several times within the cache table, once for each combination ofDOC_ID
andPOSITION
values.DOC_ID
The document ID of the newly inserted row. This value might reflect the value of an ID column that you defined for the underlying table, or it can be a sequence value generated by
InnoDB
when the table contains no suitable column.POSITION
The position of this particular instance of the word within the relevant document identified by the
DOC_ID
value. The value does not represent an absolute position; it is an offset added to thePOSITION
of the previous instance of that word.
Notes
This table is empty initially. Before querying it, set the value of the
innodb_ft_aux_table
system variable to the name (including the database name) of the table that contains theFULLTEXT
index; for exampletest/articles
. The following example demonstrates how to use theinnodb_ft_aux_table
system variable to show information about aFULLTEXT
index for a specified table.- body TEXT,
- ('MySQL Tutorial','DBMS stands for DataBase ...'),
- ('How To Use MySQL Well','After you went through a ...'),
- ('Optimizing MySQL','In this tutorial we will show ...'),
- ('1001 MySQL Tricks','1. Never run mysqld as root. 2. ...'),
- ('MySQL vs. YourSQL','In the following database comparison ...'),
- ('MySQL Security','When configured properly, MySQL ...');
- +------------+-----------+--------+----------+
- +------------+-----------+--------+----------+
- | 1001 | 1 | 4 | 0 |
- | comparison | 1 | 5 | 44 |
- | configured | 1 | 6 | 20 |
- +------------+-----------+--------+----------+
You must have the
PROCESS
privilege to query this table.Use the
INFORMATION_SCHEMA
COLUMNS
table or theSHOW COLUMNS
statement to view additional information about the columns of this table, including data types and default values.For more information about
InnoDB
FULLTEXT
search, see Section 15.6.2.4, “InnoDB FULLTEXT Indexes”, and Section 12.9, “Full-Text Search Functions”.
Traduction non disponible
Le manuel MySQL n'est pas encore traduit en français sur l'infobrol. Seule la version anglaise est disponible pour l'instant.
Document créé le 26/06/2006, dernière modification le 26/10/2018
Source du document imprimé : https://www.gaudry.be/mysql-rf-innodb-ft-index-cache-table.html
L'infobrol est un site personnel dont le contenu n'engage que moi. Le texte est mis à disposition sous licence CreativeCommons(BY-NC-SA). Plus d'info sur les conditions d'utilisation et sur l'auteur.
Références
Ces références et liens indiquent des documents consultés lors de la rédaction de cette page, ou qui peuvent apporter un complément d'information, mais les auteurs de ces sources ne peuvent être tenus responsables du contenu de cette page.
L'auteur de ce site est seul responsable de la manière dont sont présentés ici les différents concepts, et des libertés qui sont prises avec les ouvrages de référence. N'oubliez pas que vous devez croiser les informations de sources multiples afin de diminuer les risques d'erreurs.