MySQL Database plus index

To add a normal index:

ALTER TABLE ' cmf_cz_czfjbxx ' ADD INDEX index_xz (' XZ ')
ALTER TABLE ' cmf_cz_czfjbxx ' ADD INDEX index_zzyt (' Zzyt ')
ALTER TABLE ' cmf_cz_czrxx ' ADD INDEX index_zjlx (' ZJLX ')
ALTER TABLE ' cmf_cz_fwjbxx ' ADD INDEX index_tjrid (' Tjrid ')
ALTER TABLE ' cmf_cz_fwjbxx_shjg ' ADD INDEX index_ga_shjg (' GA_SHJG ');
ALTER TABLE ' cmf_cz_fwjbxx_shjg ' ADD INDEX index_xf_shjg (' XF_SHJG ');
ALTER TABLE ' cmf_cz_fwjbxx_shjg ' ADD INDEX index_zj_shjg (' ZJ_SHJG ');
ALTER TABLE ' cmf_cz_fzjbxx ' ADD INDEX index_zjlx (' ZJLX ');
ALTER TABLE ' cmf_cz_fzjbxx ' ADD INDEX index_xz (' XZ ');
ALTER TABLE ' cmf_cz_fwjbxx ' ADD INDEX index_flag (' flag ')

Normal index loading requires fields on the associated field and the so-called criteria above.

But with the subsequent increase in the amount of data, the index has some limitations, the great god see this article, I hope to give a point of view, in the optimization of data query, thank you.

1.PRIMARY key (primary key index)
Mysql>alter TABLE ' table_name ' ADD PRIMARY KEY (' column ')
2.UNIQUE (unique index)
Mysql>alter TABLE ' table_name ' ADD UNIQUE (' column ')
3.INDEX (normal index)
Mysql>alter TABLE ' table_name ' ADD INDEX index_name (' column ')
4.FULLTEXT (full-text index)
Mysql>alter TABLE ' table_name ' ADD fulltext (' column ')
5. Multi-column index
Mysql>alter TABLE ' table_name ' ADD INDEX index_name (' column1 ', ' column2 ', ' column3 ')

MySQL Database plus index