在上一篇中,我们详细介绍了InnoDB 层的锁、事务、及其相关的统计信息字典表,本期我们将为大家带来系列第七篇《InnoDB 层全文索引字典表 | 全方位认识 information_schema》。
| INNODB_FT_CONFIG
该表提供查询有关InnoDB表的FULLTEXT索引和关联的元数据信息
下面是该表中存储的信息内容
root@localhost : test 11:58:58> SELECT * FROM INFORMATION_SCHEMA.INNODB_FT_CONFIG;
+---------------------------+-------+
| KEY | VALUE |
+---------------------------+-------+
| optimize_checkpoint_limit | 180 |
| synced_doc_id | 0 |
| stopword_table_name | |
| use_stopword | 1 |
+---------------------------+-------+
4 rows in set (0.00 sec)
字段含义如下:
PS:
| INNODB_FT_BEING_DELETED
该表仅在OPTIMIZE TABLE语句执行维护操作期间作为INNODB_FT_DELETED表的快照数据存放使用。运行OPTIMIZE TABLE语句时,会先清空INNODB_FT_BEING_DELETED表中的数据,保存INNODB_FT_DELETED表中的快照数据到INNODB_FT_BEING_DELETED表,并从INNODB_FT_DELETED表中删除DOC_ID。由于INNODB_FT_BEING_DELETED表中的内容通常生命周期较短,因此该表中的数据对于监控或者调试来说用处并不大
下面是该表中存储的信息内容
# 设置innodb_ft_aux_table系统参数
root@localhost : test 11:50:16> SET GLOBAL innodb_ft_aux_table = 'test/test';
Query OK, 0 rows affected (0.00 sec)
# 创建全文索引
root@localhost : test 11:26:30> select * from test;
+------+---------+
| id | test |
+------+---------+
| 1 | a b c d |
| 1 | a b c d |
| 2 | a b c d |
+------+---------+
3 rows in set (0.00 sec)
root@localhost : test 11:51:06> alter table test add fulltext i_test(test);
Query OK, 0 rows affected, 1 warning (0.13 sec)
Records: 0 Duplicates: 0 Warnings: 1
# 删除表中的数据
root@localhost : test 11:55:09> delete from test where id=1;
Query OK, 2 rows affected (0.06 sec)
# 查询INNODB_FT_DELETED表和INNODB_FT_BEING_DELETED表中的数据,可以发现INNODB_FT_BEING_DELETED为空值,而INNODB_FT_DELETED表存放着被删除的全文索引值
root@localhost : test 11:56:12> select * from information_schema.INNODB_FT_DELETED;
+--------+
| DOC_ID |
+--------+
| 2 |
| 3 |
+--------+
2 rows in set (0.00 sec)
root@localhost : test 11:57:10> select * from information_schema.INNODB_FT_BEING_DELETED;
Empty set (0.00 sec)
# 执行optimize table语句,然后再次查询INNODB_FT_BEING_DELETED和INNODB_FT_DELETED表,如果表中数据够大,在执行optimize table语句期间,可以发现INNODB_FT_DELETED表为空值,INNODB_FT_BEING_DELETED表存放着之前被删除的全文索引值
root@localhost : test 11:57:15> optimize table test;
+-----------+----------+----------+-------------------------------------------------------------------+
| Table | Op | Msg_type | Msg_text |
+-----------+----------+----------+-------------------------------------------------------------------+
| test.test | optimize | note | Table does not support optimize, doing recreate + analyze instead |
| test.test | optimize | status | OK |
+-----------+----------+----------+-------------------------------------------------------------------+
2 rows in set (0.08 sec)
root@localhost : test 11:58:50> select * from information_schema.INNODB_FT_DELETED;
Empty set (0.00 sec)
root@localhost : test 11:58:55> select * from information_schema.INNODB_FT_BEING_DELETED;
Empty set (0.00 sec)
字段含义如下:
| INNODB_FT_DELETED
该表提供查询从InnoDB表的FULLTEXT索引中删除的行信息。它的存在是为了避免在InnoDB FULLTEXT索引的DML操作期间进行昂贵的索引重组操作,新删除的全文索引中单词的信息将单独存储在该表中,在执行文本搜索时从中过滤出搜索结果,该表中的信息仅在执行OPTIMIZE TABLE语句时清空
下面是该表中存储的信息内容
# 使用innodb_ft_aux_table 选项指定包含全文索引的Innodb引擎表
root@localhost : test 11:41:01> SET GLOBAL innodb_ft_aux_table = 'test/test';
Query OK, 0 rows affected (0.00 sec)
# 删除表中的行
root@localhost : test 11:41:24> delete from test where id=1;
Query OK, 3 rows affected (0.02 sec)
# 查询INNODB_FT_DELETED表,此时INNODB_FT_DELETED表中就包含了被删除的全文索引的DOC_ID值
root@localhost : test 11:41:29> SELECT * FROM INFORMATION_SCHEMA.INNODB_FT_DELETED;
+--------+
| DOC_ID |
+--------+
| 4 |
| 5 |
| 6 |
| 10 |
| 11 |
| 12 |
| 13 |
+--------+
7 rows in set (0.00 sec)
字段含义如下:
| INNODB_FT_DEFAULT_STOPWORD
该表为默认的全文索引停用词表,提供查询停用词列表值。启用停用词表需要开启参数innodb_ft_enable_stopword=ON,该参数默认为ON,启用停用词功能之后,如果innodb_ft_user_stopword_table选项(针对指定的innodb引擎表中的全文索引生效)自定义了停用词库表名称值,则停用词功能使用innodb_ft_user_stopword_table选项指定的停用词表,如果innodb_ft_user_stopword_table选项未指定,而innodb_ft_server_stopword_table选项(针对所有的innodb引擎表中的全文索引生效)自定义了停用词库表名称值,则同停用词功能使用innodb_ft_server_stopword_table选项指定的停用词表,如果innodb_ft_server_stopword_table选项也未指定,则使用默认的停用词表,即INNODB_FT_DEFAULT_STOPWORD表。
下面是该表中存储的信息内容
# 默认的停用词列表值如下
admin@localhost : information_schema 06:46:38> select * from INNODB_FT_DEFAULT_STOPWORD;
+-------+
| value |
+-------+
| a |
| about |
| an |
| are |
| as |
| at |
| be |
| by |
| com |
| de |
| en |
| for |
| from |
| how |
| i |
| in |
| is |
| it |
| la |
| of |
| on |
| or |
| that |
| the |
| this |
| to |
| was |
| what |
| when |
| where |
| who |
| will |
| with |
| und |
| the |
| www |
+-------+
36 rows in set (0.00 sec)
字段含义如下:
| INNODB_FT_INDEX_CACHE
该表中提供查询包含FULLTEXT索引的innodb存储引擎表中新插入行的全文索引标记信息。它存在的目的是为了避免在DML操作期间进行昂贵的索引重组,新插入的全文索引的单词的信息被单独存储在该表中,直到对表执行OPTIMIZE TABLE语句时、或者关闭服务器时、或者当高速缓存中存放的信息大小超过了innodb_ft_cache_size或innodb_ft_total_cache_size系统配置参数指定的大小才会执行清理
下面是该表中存储的信息内容
# 设置innodb_ft_aux_table选项指定需要记录那个innodb表中的全文索引新插入的值
root@localhost : test 11:41:01> SET GLOBAL innodb_ft_aux_table = 'test/test';
Query OK, 0 rows affected (0.00 sec)
# 执行插入
root@localhost : test 11:40:57> insert into test values(1,'a b dddd');
Query OK, 1 row affected (0.00 sec)
root@localhost : test 11:41:00> insert into test values(1,'a b dddd');
Query OK, 1 row affected (0.01 sec)
root@localhost : test 11:41:01> insert into test values(1,'a b dddd');
Query OK, 1 row affected (0.00 sec)
# 查看INNODB_FT_INDEX_CACHE表中的记录数据
root@localhost : test 11:59:18> SELECT * FROM INFORMATION_SCHEMA.INNODB_FT_INDEX_CACHE;
+------+--------------+-------------+-----------+--------+----------+
| WORD | FIRST_DOC_ID | LAST_DOC_ID | DOC_COUNT | DOC_ID | POSITION |
+------+--------------+-------------+-----------+--------+----------+
| dddd | 6 | 13 | 8 | 6 | 4 |
| dddd | 6 | 13 | 8 | 7 | 4 |
| dddd | 6 | 13 | 8 | 8 | 4 |
| dddd | 6 | 13 | 8 | 9 | 4 |
| dddd | 6 | 13 | 8 | 10 | 4 |
| dddd | 6 | 13 | 8 | 11 | 4 |
| dddd | 6 | 13 | 8 | 12 | 4 |
| dddd | 6 | 13 | 8 | 13 | 4 |
+------+--------------+-------------+-----------+--------+----------+
8 rows in set (0.00 sec)
字段含义如下:
| INNODB_FT_INDEX_TABLE
该表中提供查询关于innodb表全文索引中用于反向文本查找的倒排索引的分词信息
下面是该表中存储的信息内容
# 启用innodb_optimize_fulltext_only系统配置参数
root@localhost : test 12:28:29> SET GLOBAL innodb_optimize_fulltext_only=ON;
Query OK, 0 rows affected (0.00 sec)
# 执行优化表语句
root@localhost : test 12:28:41> OPTIMIZE TABLE test;
+-----------+----------+----------+----------+
| Table | Op | Msg_type | Msg_text |
+-----------+----------+----------+----------+
| test.test | optimize | status | OK |
+-----------+----------+----------+----------+
1 row in set (0.02 sec)
# 设置innodb_ft_aux_table 系统配置参数为刚刚执行优化的表
root@localhost : test 12:28:48> SET GLOBAL innodb_ft_aux_table = 'test/test';
Query OK, 0 rows affected (0.00 sec)
# 查询INNODB_FT_INDEX_TABLE 表中记录的值
root@localhost : test 12:28:55> select * from information_schema.INNODB_FT_INDEX_TABLE ;
+----------+--------------+-------------+-----------+--------+----------+
| WORD | FIRST_DOC_ID | LAST_DOC_ID | DOC_COUNT | DOC_ID | POSITION |
+----------+--------------+-------------+-----------+--------+----------+
| edf | 9 | 10 | 2 | 9 | 0 |
| edf | 9 | 10 | 2 | 10 | 0 |
| edfa | 9 | 10 | 2 | 9 | 4 |
| edfa | 9 | 10 | 2 | 10 | 4 |
| eeee | 8 | 8 | 1 | 8 | 4 |
| eeeesdf | 9 | 9 | 1 | 9 | 9 |
| eeeesdfs | 10 | 10 | 1 | 10 | 9 |
| dddd | 3 | 5 | 3 | 3 | 4 |
| dddd | 3 | 5 | 3 | 4 | 4 |
| dddd | 3 | 5 | 3 | 5 | 4 |
| ddde | 6 | 6 | 1 | 6 | 4 |
| ddee | 7 | 7 | 1 | 7 | 4 |
+----------+--------------+-------------+-----------+--------+----------+
12 rows in set (0.00 sec)
字段含义如下:与INNODB_FT_INDEX_CACHE表字段含义相同
本期内容就介绍到这里,本期内容参考链接如下:
https://dev.mysql.com/doc/refman/5.7/en/innodb-ft-config-table.html
https://dev.mysql.com/doc/refman/5.7/en/innodb-ft-being-deleted-table.html
https://dev.mysql.com/doc/refman/5.7/en/innodb-ft-deleted-table.html
https://dev.mysql.com/doc/refman/5.7/en/innodb-ft-default-stopword-table.html
https://dev.mysql.com/doc/refman/5.7/en/innodb-ft-index-table-table.html
https://dev.mysql.com/doc/refman/5.7/en/innodb-ft-index-cache-table.html
| 作者简介
《千金良方——MySQL性能优化金字塔法则》、《数据生态:MySQL复制技术与生产实践》作者之一。熟悉MySQL体系结构,擅长数据库的整体调优,喜好专研开源技术,并热衷于开源技术的推广,在线上线下做过多次公开的数据库专题分享,发表过近100篇数据库相关的研究文章。
全文完。