mssql-server

name

mssql-server

description

Writes, optimizes, and debugs T-SQL queries. Explains SQL Server internals, troubleshoots performance issues, and guides database administration tasks including backup/restore, high availability, security, and index design. Use when the user asks about T-SQL syntax, SQL Server administration, query performance, stored procedures, indexes, locking, transactions, backup/restore, high availability, security, or any MSSQL-related topic — even without saying 'SQL Server' explicitly. Also trigger on terms like SSMS, tempdb, bcp, sqlcmd, MSSQL, sp_executesql, NOLOCK, columnstore, Hekaton, RCSI, param sniffing, or execution plan.

MSSQL Server Skill

How to use this skill

1. Identify the topic using the routing table below (keyword → file mapping).
2. Read the relevant reference file(s). Never answer from memory alone when a reference file covers the topic.
3. Cross-cutting questions — identify ALL matching rows and read each file. Check "See Also" sections for additional files.
4. Ambiguous keywords — read the "Disambiguation" column. When in doubt, load both files.
5. Response format: Lead with code/pattern, follow with caveats in admonition blocks, end with source links.

Quick Examples

-- Basic filtered query with pagination
SELECT CustomerName, Email
FROM Customer
WHERE Status = 'Active'
ORDER BY CustomerName
OFFSET 0 ROWS FETCH NEXT 25 ROWS ONLY;

-- Create a covering index
CREATE NONCLUSTERED INDEX IX_Customer_Status
ON Customer(Status) INCLUDE (CustomerName, Email);

---

Routing Table

Keywords / Triggers	File	Scope	Disambiguation
CREATE TABLE, ALTER TABLE, DROP, schema, sequence, synonym, computed column	references/01-syntax-ddl.md	DDL syntax reference
SELECT, JOIN, subquery, UNION, INTERSECT, EXCEPT, window function, PIVOT, UNPIVOT, APPLY, OFFSET FETCH, pagination	references/02-syntax-dql.md	DQL / query syntax
INSERT, UPDATE, DELETE, MERGE, OUTPUT clause, upsert	references/03-syntax-dml.md	DML syntax & patterns
CTE, WITH, recursive CTE, anchor member, MAXRECURSION	references/04-ctes.md	CTEs (recursive & non-recursive)
VIEW, indexed view, SCHEMABINDING, partitioned view, WITH CHECK OPTION	references/05-views.md	Views
stored procedure, param sniffing, TVP, output param, EXECUTE AS user, impersonation, security context	references/06-stored-procedures.md	Stored procedures	OPTION RECOMPILE: here for proc-level usage; see also 32 for query-level hint. EXECUTE AS: here for proc context; see also 15 for server/db principals
function, scalar UDF, inline TVF, multi-statement TVF, determinism, UDF inlining	references/07-functions.md	User-defined functions
index, clustered, nonclustered, covering index, include columns, fill factor, fragmentation, heap, forwarded record, rebuild, reorganize, B-tree structure	references/08-indexes.md	Index design & maintenance	missing index: here for DMV queries and index design; see also 32 for broader perf diagnostics
columnstore, delta store, rowgroup, batch mode, tuple mover, segment elimination	references/09-columnstore-indexes.md	Columnstore indexes
partition, partition function, partition scheme, partition switching, sliding window, STATISTICS_INCREMENTAL	references/10-partitioning.md	Table partitioning
user-defined type, CLR type, table type, alias type, spatial, geometry, geography, sparse column	references/11-custom-data-types.md	Custom data types
CHECK constraint, DEFAULT constraint, UNIQUE constraint, foreign key, cascade, referential integrity, functional constraint, cross-database constraint, cross-schema, computed column index