根据：帮助标签二进制搜索，标签文件在每次查找时搜索二进制(或线性)，因此不需要重新加载文件：
@H_301_7@*tag-binary-search*
Vim uses binary searching in the tags file to find the desired tag quickly
(when enabled at compile time |+tag_binary|). But this only works if the
tags file was sorted on ASCII byte value. Therefore,if no match was found,another try is done with a linear search. If you only want the linear search,reset the 'tagbsearch' option. Or better: Sort the tags file!
Note that the binary searching is disabled when not looking for a tag with a
specific name. This happens when ignoring case and when a regular expression
is used that doesn't start with a fixed string. Tag searching can be a lot
slower then. The former can be avoided by case-fold sorting the tags file.
See 'tagbsearch' for details.
