MySQL 参数预配置 索引参数
1 全文索引
全文索引有以下几个参数.
mysql> show variables like 'ft_%';
+--------------------------+----------------+
| Variable_name | Value |
+--------------------------+----------------+
| ft_boolean_syntax | + -><()~*:""&| |
| ft_max_word_len | 84 |
| ft_min_word_len | 4 |
| ft_query_expansion_limit | 20 |
| ft_stopword_file | (built-in) |
+--------------------------+----------------+
2 [ft_max_word_len]
| Property | Value |
|---|---|
| Command-Line Format | --ft-max-word-len=# |
| System Variable | [ft_max_word_len] |
| Scope | Global |
| Dynamic | No |
| [SET_VAR] Hint Applies | No |
| Type | integer |
| Minimum Value | 10 |
对于MyISAM 表,此参数设置为索引中最大的字符串长度.
::: alert-info
Note
如果更改了选项,myisam 表上全文索引,需要使用REPAIR TABLE *`tbl_name`*QUICK 重新生成索引.
:::
3 [ft_min_word_len]
| Property | Value |
|---|---|
| Command-Line Format | --ft-min-word-len=# |
| System Variable | [ft_min_word_len] |
| Scope | Global |
| Dynamic | No |
| [SET_VAR] Hint Applies | No |
| Type | integer |
| Default Value | 4 |
| Minimum Value | 1 |
| 对于myisam 的全文索引最小字符串长度 |
::: alert-info
Note
更改此变量后,需要用REPAIR TABLE *`tbl_name`*QUICK 重建myisam 索引.
:::
4 [ft_query_expansion_limit]
| Property | Value |
|---|---|
| Command-Line Format | --ft-query-expansion-limit=# |
| System Variable | [ft_query_expansion_limit] |
| Scope | Global |
| Dynamic | No |
| [SET_VAR] Hint Applies | No |
| Type | integer |
| Default Value | 20 |
| Minimum Value | 0 |
| Maximum Value | 1000 |
使用全文索引和WITH QUERY EXPANSION的最大匹配数.
查询括展时取最相关的几个值用作二次查询
5 [ft_stopword_file]
| Property | Value |
|---|---|
| Command-Line Format | --ft-stopword-file=file_name |
| System Variable | [ft_stopword_file] |
| Scope | Global |
| Dynamic | No |
| [SET_VAR] Hint Applies | No |
| Type | file name |
对于全文索引，MySQL会从 ft_stopword_file 变量指定的文件中读取不进行全文索引的过滤词表, 一行一个。若将该变量设置为空字符串(”)则禁用过滤词表。对于过滤的词表请参照storage/myisam/ft_static.c源代码
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
:::alert-warning
Note
更改ft_stopword_file 变量之后,对于MyISAM 表必须使用REPAIR TABLE *`tbl_name`* QUICK 重建全文索引.
:::
6 RTREE 索引
have_rtree_keys={YES|NO}
mysqld支持RTREE索引则为YES，否则为NO。RTREE索引用于MyISAM表的空间索引