1
for example:
CREATE INDEX idx_user_username ON user (username (6));
idx_user_username is the name of the index, does this name need to be written or reflected in the program
or will the database itself do it without our management?
2
how to measure the retrieval speed after adding an index
index generally does not need to display the specified index, but if you are not satisfied with the result of database automatic optimization, you can also specify to use the index
such as
select * from user force index (idx_user_username); the most common way to view index usage is explain
such as
explain select * from user force index (idx_user_username);
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like this SELECT * FROM material WHERE {key:value} limit 1 ...
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Table structure ...
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