mysql全文索引之停止词(stopword)

本文IT技术学习网将给大家讲述什么是mysql全文索引中的停止词（stopword也有的翻译做停止字）。

stopword

在全文索引中，如果一个词被认为是太普通或者太没价值，那么它将会被搜索索引和搜索查询忽略。innodb和myisam分别有两组不同的设置，控制着对应的stopword。

全文检索时，停止词列表将会被读取和检索，在不同的字符集和排序方式下（character_set_server and collation_server 系统变量），可能会导致在搜索时的停止词的不匹配。

停止词是否大小写敏感，取决于不同的排序方式，比如：latin1_swedish_ci下停止词是大小写敏感的，latin1_general_cs 或 latin1_bin下停止词是大小写不敏感的。

innodb的索引停止词

innodb的默认停止词列表很短。查询INFORMATION_SCHEMA.INNODB_FT_DEFAULT_STOPWORD表来查看默认的innodb停止词表。

mysql> SELECT * FROM INFORMATION_SCHEMA.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)

myisam索引的停止词

myisam索引的停止词列表与innodb不同，默认的myisam停止词列表是直接在mysql程序源码中已写入。设置ft_stopword_file系统变量来指定停止词文件，从而覆盖默认设置。

在mysql源程序的 storage/myisam/ft_static.c file文件中，你可以找到默认的myisam停止词列表：

a's able about above according

 

accordingly across actually after afterwards

 

again against ain't all allow

 

allows almost alone along already

 

also although always am among

 

amongst an and another any

 

anybody anyhow anyone anything anyway

 

anyways anywhere apart appear appreciate

 

appropriate are aren't around as

 

aside ask asking associated at

 

available away awfully be became

 

because become becomes becoming been

 

before beforehand behind being believe

 

below beside besides best better

 

between beyond both brief but

 

by c'mon c's came can

 

can't cannot cant cause causes

 

certain certainly changes clearly co

 

com come comes concerning consequently

 

consider considering contain containing contains

 

corresponding could couldn't course currently

 

definitely described despite did didn't

 

different do does doesn't doing

 

don't done down downwards during

 

each edu eg eight either

 

else elsewhere enough entirely especially

 

et etc even ever every

 

everybody everyone everything everywhere ex

 

exactly example except far few

 

fifth first five followed following

 

follows for former formerly forth

 

four from further furthermore get

 

gets getting given gives go

 

goes going gone got gotten

 

greetings had hadn't happens hardly

 

has hasn't have haven't having

 

he he's hello help hence

 

her here here's hereafter hereby

 

herein hereupon hers herself hi

 

him himself his hither hopefully

 

how howbeit however i'd i'll

 

i'm i've ie if ignored

 

immediate in inasmuch inc indeed

 

indicate indicated indicates inner insofar

 

instead into inward is isn't

 

it it'd it'll it's its

 

itself just keep keeps kept

 

know known knows last lately

 

later latter latterly least less

 

lest let let's like liked

 

likely little look looking looks

 

ltd mainly many may maybe

 

me mean meanwhile merely might

 

more moreover most mostly much

 

must my myself name namely

 

nd near nearly necessary need

 

needs neither never nevertheless new

 

next nine no nobody non

 

none noone nor normally not

 

nothing novel now nowhere obviously

 

of off often oh ok

 

okay old on once one

 

ones only onto or other

 

others otherwise ought our ours

 

ourselves out outside over overall

 

own particular particularly per perhaps

 

placed please plus possible presumably

 

probably provides que quite qv

 

rather rd re really reasonably

 

regarding regardless regards relatively respectively

 

right said same saw say

 

saying says second secondly see

 

seeing seem seemed seeming seems

 

seen self selves sensible sent

 

serious seriously seven several shall

 

she should shouldn't since six

 

so some somebody somehow someone

 

something sometime sometimes somewhat somewhere

 

soon sorry specified specify specifying

 

still sub such sup sure

 

t's take taken tell tends

 

th than thank thanks thanx

 

that that's thats the their

 

theirs them themselves then thence

 

there there's thereafter thereby therefore

 

therein theres thereupon these they

 

they'd they'll they're they've think

 

third this thorough thoroughly those

 

though three through throughout thru

 

thus to together too took

 

toward towards tried tries truly

 

try trying twice two un

 

under unfortunately unless unlikely until

 

unto up upon us use

 

used useful uses using usually

 

value various very via viz

 

vs want wants was wasn't

 

way we we'd we'll we're

 

we've welcome well went were

 

weren't what what's whatever when

 

whence whenever where where's whereafter

 

whereas whereby wherein whereupon wherever

 

whether which while whither who

 

who's whoever whole whom whose

 

why will willing wish with

 

within without won't wonder would

 

wouldn't yes yet you you'd

 

you'll you're you've your yours

 

yourself yourselves zero