How to Optimize Database Queries with LIKE Clauses and Wildcard Characters?

Optimal Indexing for Queries Involving LIKE Clauses

When optimizing database queries involving LIKE clauses, determining the most efficient index strategy can be challenging. In this scenario, we are presented with a complex query that utilizes various operators and contains a LIKE expression.

The LIKE operator, when used with wildcard characters at the beginning of the pattern, prevents the database from leveraging index benefits. However, the second LIKE expression in the given query does not start with a wildcard, making it possible for an index to be utilized.

To optimize this query, we consider several indexing options:

• tags(name, usage_guidance)
• tags(usage_guidance, name)
• tags(name)
• tags(usage_guidance)

The optimal index choice is a composite index on usage_guidance, name. This index will facilitate efficient search operations for the non-wildcard LIKE expression, enabling the query to utilize the index and optimize its execution.

However, it's important to note that the presence of other operators, such as OR and IN, can affect query performance and index effectiveness. Providing the actual table structure and sample data would enable further analysis and potential query optimizations.

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