What Is a Full-Text Indexes in Microsoft SQL Server?
An inverted token index is maintained by the full-text engine with language-specific word breakers, stemming, and stoplists.
How the Full-Text Indexes Algorithm Works
An inverted token index is maintained by the full-text engine with language-specific word breakers, stemming, and stoplists.
When to Use Full-Text Indexes
Word and linguistic searches using CONTAINS or FREETEXT.
How to Create a Microsoft SQL Server Full-Text Indexes
Review data quality, existing structures, feature support, build time, and deployment requirements before creating an index on a production table.
CREATE FULLTEXT CATALOG ProductCatalog AS DEFAULT;
CREATE FULLTEXT INDEX ON dbo.Products(Description LANGUAGE 1033) KEY INDEX PK_Products;Full-Text Indexes Query Example
This example demonstrates the matching query shape. Check the execution plan to confirm that the engine can use the index.
SELECT ProductId FROM dbo.Products WHERE CONTAINS(Description, '"database indexing"');Queries Supported by Full-Text Indexes
Word and linguistic searches using CONTAINS or FREETEXT. A similar-looking predicate may not use the same access path; operators, expressions, key order, and data type all matter.
Read Performance, Storage, and Write Costs
Population/change tracking adds separate storage and latency; semantics differ from LIKE. Indexes reduce some search work but require storage and add maintenance to writes.
Full-Text Indexes Limitations and Common Mistakes
Requires a suitable unique key index; language, stoplist, and population state affect results.
Do not assume that an index being present means the optimizer chose it or that the query became selective.
How to Measure and Tune Full-Text Indexes
Monitor population and test language/query mode; combine with relational indexes where needed.
Compare representative plans and timings before and after, including concurrent writes and realistic data volumes.
Full-Text Indexes Questions
Will the database always use this index?
No. The optimizer weighs selectivity, estimated costs, statistics, cache state, and the amount of data returned.
What should I verify before production?
Confirm version support, query compatibility, write overhead, build/rollback procedures, and index behavior during backup and recovery.
Official Microsoft SQL Server Index Documentation
Check Microsoft Learn: SQL Server Indexes for release-specific requirements and supported operators.