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Yes, MySQL can use multiple index for a single query. The optimizer will determine which indexes will benefit the query. You can use EXPLAIN to obtain information about how MySQL executes a statement. You can add or ignore indexes using hints like so: SELECT * FROM t1 USE INDEX (i1) IGNORE INDEX FOR ORDER BY (i2) ORDER BY a;
Use EXPLAIN and read the results to find out when MySQL uses your indices. If a table has six columns and all of them are searchable, should i index all of them or none of them? Indexing all six columns isn't always the best practice.
4 sty 2023 · Using indexes in MySQL has multiple benefits. The most common are speeding up WHERE conditional queries (with exact match conditions and comparisons), sorting data with ORDER BY clauses more quickly, and enforcing value uniqueness. However, using indexes may degrade peak database performance in some circumstances.
12 sty 2024 · In this action-packed tutorial, you’ll navigate the intricacies of MySQL indexes with practical, hands-on examples that will transform you into an indexing maestro. Keep reading and master the art of optimizing database management!
MySQL uses indexes for these operations: To find the rows matching a WHERE clause quickly. To eliminate rows from consideration. If there is a choice between multiple indexes, MySQL normally uses the index that finds the smallest number of rows (the most selective index).
MySQL is capable of doing an INDEX MERGE which allows MySQL to search on both indexes and merge the results. Of course, the MySQL Query Optimizer is the arbitrator of this process. From my perspective, just looking at your query and its WHERE clause, I would create a compound index on your table and an additional index.
MySQL uses indexes to rapidly locate rows with specific column values. Without an index, MySQL must scan the entire table to find the relevant rows. The larger the table, the slower the search becomes.
