Reputation: 1049
I need a query to see if a table already has any indexes on it.
Upvotes: 104
Views: 556142
Reputation: 243
Simply you can find index name and column names of a particular table using below command
SP_HELPINDEX 'tablename'
It works for me
Upvotes: 20
Reputation: 31
check this as well This gives an overview of associated constraints across a database. Please also include facilitating where condition with table name of interest so gives information faster.
select
a.TABLE_CATALOG as DB_name,a.TABLE_SCHEMA as tbl_schema, a.TABLE_NAME as tbl_name,a. CONSTRAINT_NAME as constraint_name,b.CONSTRAINT_TYPE
from INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE a
join INFORMATION_SCHEMA.TABLE_CONSTRAINTS b on
a.CONSTRAINT_NAME=b.CONSTRAINT_NAME
Upvotes: 2
Reputation: 2922
Created a stored procedure to list indexes for a table in database in SQL Server
create procedure _ListIndexes(@tableName nvarchar(200))
as
begin
/*
exec _ListIndexes '<YOUR TABLE NAME>'
*/
SELECT DB_NAME(DB_ID()) as DBName,SCH.name + '.' + TBL.name AS TableName,IDX.name as IndexName, IDX.type_desc AS IndexType,COL.Name as ColumnName,IC.*
FROM sys.tables AS TBL
INNER JOIN sys.schemas AS SCH ON TBL.schema_id = SCH.schema_id
INNER JOIN sys.indexes AS IDX ON TBL.object_id = IDX.object_id
INNER JOIN sys.index_columns IC ON IDX.object_id = IC.object_id and IDX.index_id = IC.index_id
INNER JOIN sys.columns COL ON ic.object_id = COL.object_id and IC.column_id = COL.column_id
where TBL.name = @tableName
ORDER BY TableName,IDX.name
end
Upvotes: 5
Reputation: 1117
First you check your table id (aka object_id)
SELECT * FROM sys.objects WHERE type = 'U' ORDER BY name
then you can get the column's names. For example assuming you obtained from previous query the number 4 as object_id
SELECT c.name
FROM sys.index_columns ic
INNER JOIN sys.columns c ON c.column_id = ic.column_id
WHERE ic.object_id = 4
AND c.object_id = 4
Upvotes: 3
Reputation: 36827
On Oracle:
Determine all indexes on table:
SELECT index_name
FROM user_indexes
WHERE table_name = :table
Determine columns indexes and columns on index:
SELECT index_name
, column_position
, column_name
FROM user_ind_columns
WHERE table_name = :table
ORDER BY index_name, column_order
References:
Upvotes: 3
Reputation: 10073
Here is what I used for TSQL which took care of the problem that my table name could contain the schema name and possibly the database name:
DECLARE @THETABLE varchar(100);
SET @THETABLE = 'theschema.thetable';
select i.*
from sys.indexes i
where i.object_id = OBJECT_ID(@THETABLE)
and i.name is not NULL;
The use case for this is that I wanted the list of indexes for a named table so I could write a procedure that would dynamically compress all indexes on a table.
Upvotes: 5
Reputation: 2382
If you just need the indexed columns EXEC sp_helpindex 'TABLE_NAME'
Upvotes: 34
Reputation: 46933
Most modern RDBMSs support the INFORMATION_SCHEMA
schema. If yours supports that, then you want either INFORMATION_SCHEMA.TABLE_CONSTRAINTS
or INFORMATION_SCHEMA.KEY_COLUMN_USAGE
, or maybe both.
To see if yours supports it is as simple as running
select count(*) from INFORMATION_SCHEMA.TABLE_CONSTRAINTS
EDIT: SQL Server does have INFORMATION_SCHEMA
, and it's easier to use than their vendor-specific tables, so just go with it.
Upvotes: 8
Reputation: 8356
On SQL Server, this will list all the indexes for a specified table:
select * from sys.indexes
where object_id = (select object_id from sys.objects where name = 'MYTABLE')
This query will list all tables without an index:
SELECT name
FROM sys.tables
WHERE OBJECTPROPERTY(object_id,'IsIndexed') = 0
And this is an interesting MSDN FAQ on a related subject:
Querying the SQL Server System Catalog FAQ
Upvotes: 134
Reputation: 546333
If you're using MySQL you can run SHOW KEYS FROM table
or SHOW INDEXES FROM table
Upvotes: 44