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Do like queries use indexes?
When you do LIKE ‘%text%’ it can’t use the index because there can be a variable number of characters before text.
Does SQL like use index?
Indexing LIKE Filters. The SQL LIKE operator very often causes unexpected performance behavior because some search terms prevent efficient index usage. That means that there are search terms that can be indexed very well, but others can not. It is the position of the wild card characters that makes all the difference.
What are alternatives to operators?
You could create a FULLTEXT index. To my knowledge there’s no alternative to like or contains (full text search feature) which would give better performance. What you can do is try to improve performance by optimising your query. To do that, you need to know a bit about your users & how they’ll use your system.
Are there less used indexes on the database?
However, it’s not so simple as it appears: These may be the less used indexes on the database, but when the most used ones have numbers like 100.000 seeks, it will not be difficult to find the less used ones with numbers such as 10.000 .
When is the index not being used in XML?
However, analysing the query plan XML you will discover the index is most being used for updates, meaning the index is being updated when a record is updated. The plans where the index is being used for update are not needed for us on this query, they are exactly what create problems for performance.
What does it mean when an index is not being used?
It means the index tree is being used to go directly to the records we need. Index Scan: Not so good as an index seek, so it could be better. However, sometimes even an index scan is good, a non clustered index scan means the pages of that index are smaller an better for a scan than the pages of the clustered index.
How to know if index columns are being used?
Your can then query on: KM. KM. In my experience the first %-sign will make any index useless, but one at the end will use the index. To answer the metrics part of your question: The type of index/table scan/seek being performed is a good indicator for knowing if an index is being (properly) used.