mysql Multi-table query , The data that is indexed and queried without index are different
CSDN Q & A 2022-02-13 08:28:33 阅读数:249
mysql Multi-table query , The data that is indexed and queried without index are different
What is it like sql And data , Post it to see
Another possibility is , Full text index word segmentation may be similar to like The results are different , I don't know what your situation is
The index has nothing to do with the queried data , But it has something to do with the time when the data is queried , So your question should have nothing to do with the index !
First, it's impossible , Indexing is just a way to improve retrieval efficiency . The result is different, just the appearance ,sql Adding an index leaves out the fields with empty index fields , No, it's all found . If help , Please accept !
Indexes are built on Columns , A data structure that sorts columns . The function is to speed up the query .
There are more data in the table , The index is used only when the data in the column is neat Small tables or fields often change, which is unnecessary .
where There are conditions <> !=
where There are conditions Aggregate functions
Fuzzy query %xxx
There are a lot of duplicate data in the column When the index is invalid ;
Neither will affect the query data Just for efficiency It should be you sql The problem has nothing to do with the index
No plan, no truth , Unless BUG 了 . this ... You first upgrade to the latest version to see .
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