Redundant Indexes

The next script, gets redundant indexes, in a given database.
I run it in the query Analyzer, one statement at a time.

PLEASE: review the output, before drop any index.


USE ....

-- step 1
-- gets an tab,idx,col,order view
create view listaidxcols as
select SO.name as tabname,
SI.name as idxname,
IK.keyno as keyno,
SC.name as colname
from sysindexkeys IK,
syscolumns SC,
sysindexes SI,
sysobjects SO
where -- Link syscolumns
IK.id=SC.id
and IK.colid=SC.colid
-- Link sysindexes
and IK.id=SI.id
and IK.indid=SI.indid
-- Link sysObjects (tables)
and IK.id=SO.id
and SO.xtype='U'
-- no internal indexes
and SI.name not like '_WA_Sys_%'
and SI.name not like 'hind_%'

--step 2: view to get # of columns per index
create view cantcolsidx
as select tabname,
idxname,
count(*) as numllaves
from listaidxcols
group by tabname,idxname


-- step 3
-- the redundant index list
select A.tabname as tabla,A.idxname as Aidx, B.idxname as Bidx
from cantcolsidx A, cantcolsidx B
where A.tabname = B.tabname
and A.numllaves < B.numllaves
and A.idxname <> B.idxname
and A.numllaves in (
select count(*)
from listaidxcols C, listaidxcols D
where C.tabname=A.tabname
and C.idxname=A.idxname
and D.tabname=B.tabname
and D.idxname=B.idxname
and C.idxname<>D.idxname
and C.colname=D.colname
and C.keyno =D.keyno
)

--clean up
drop view listaidxcols;
drop view cantcolsidx;