Is it possible to write a query that returns all tables that have clustered indexes that are not based on an identity key?
If you open the Indexes node under the table name, you will see the new index name ix_parts_id with type Clustered . When executing the following statement, SQL Server traverses the index (Clustered Index Seek) to locate the rows, which is faster than scanning the whole table.
sp_helpindex is a system stored procedure which lists the information of all the indexes on a table or view. This is the easiest method to find the indexes in a table. sp_helpindex returns the name of the index, description of the index and the name of the column on which the index was created.
A clustered index is an index which defines the physical order in which table records are stored in a database. Since there can be only one way in which records are physically stored in a database table, there can be only one clustered index per table. By default a clustered index is created on a primary key column.
Clustered indexes are stored as trees. With clustered index, the actual data is stored in the leaf nodes. This can speed up getting the data when a lookup is performed on the index.
How about this:
SELECT
TableName = t.name,
ClusteredIndexName = i.name,
ColumnName = c.Name
FROM
sys.tables t
INNER JOIN
sys.indexes i ON t.object_id = i.object_id
INNER JOIN
sys.index_columns ic ON i.index_id = ic.index_id AND i.object_id = ic.object_id
INNER JOIN
sys.columns c ON ic.column_id = c.column_id AND ic.object_id = c.object_id
WHERE
i.index_id = 1 -- clustered index
AND c.is_identity = 0
AND EXISTS (SELECT *
FROM sys.columns c2
WHERE ic.object_id = c2.object_id AND c2.is_identity = 1)
OK, this query will list those primary keys that have a column which is not identity, but where there's also additionally a second column in the primary key constraint that IS an IDENTITY
column.
SELECT s.name AS schema_name, o.name AS object_name, i.name AS index_name
FROM sys.indexes i
JOIN sys.objects o ON i.object_id = o.object_id
JOIN sys.schemas s ON o.schema_id = s.schema_id
WHERE i.type = 1 -- Clustered index
--AND o.is_ms_shipped = 0 -- Uncomment if you want to see only user objects
AND NOT EXISTS (
SELECT *
FROM sys.index_columns ic INNER JOIN sys.columns c ON c.object_id = ic.object_id AND c.column_id = ic.column_id
WHERE ic.object_id = i.object_id AND ic.index_id = i.index_id
AND c.is_identity = 1 -- Is identity column
)
ORDER BY schema_name, object_name, index_name;
Sample output (AdventureWorks2008R2):
schema_name object_name index_name
-------------- --------------------------- --------------------------------------------------------------------
HumanResources Employee PK_Employee_BusinessEntityID
HumanResources EmployeeDepartmentHistory PK_EmployeeDepartmentHistory_BusinessEntityID_StartDate_DepartmentID
HumanResources EmployeePayHistory PK_EmployeePayHistory_BusinessEntityID_RateChangeDate
Person BusinessEntityAddress PK_BusinessEntityAddress_BusinessEntityID_AddressID_AddressTypeID
Person BusinessEntityContact PK_BusinessEntityContact_BusinessEntityID_PersonID_ContactTypeID
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