If I have a table with Col1 + Col2 as PK. But most of the queries use Col1, Col2, Col3 and Col4 in the queries, should I create another unique index on this combination? If not, my queries do an index scan. Just wondering is there a general rule for this kind of situation as I have a lot of such cases in my database.
View 13 RepliesCurrently we are facing some performance issue while accessing the archive data from the archive tables. the archive table is hugh and it contains around 100,000,000 records and this archive table is being used in few reports and in our commission cycles too. since we are facing performance issues we are rebuilding index once in a week on all the indexes on this archive table.
We have 1 clustered index and 5 non clustered indexes, every time when we rebuild all these indexes on this table it is taking more time, more often rebuilding the clustered index itself is taking approx. 1hr which is consuming more time. wanted to know is there any useful to rebuild clustered indexes or not, if yes then what would be the better way. if not then do we need to rebuild only non clustered indexes.
I have a series of indexes that are showing as statistics. Is it because they are filtered or are defined as constraints?
View 5 Replies View RelatedThis website describes how Merge statements should be optimized by the use of indexes on the target?source tables: [URL]..... It says that a clustered index should be created on the join column in the target and a unique covering index on the source table.Â
I have read in other articles that insert/delete/update statements perform worse on tables with clustered indexes as the leaf level pages will have to be reorganized.
Why in the case of Merge statement having a indexes actually improve the performance of insert/delete/update statements?
I have a database around 500 GB. right now the database have only one data file and one log, it has only one filegroup also.all the indexes and table are placed in Primary Filegroup . we are going to separate them. the planing is to move all the indexes to Secondary filegroup and all the table will be in Primary filegroup.But there will be a problem while implementing it because there are around 600 tables and each table have at least 2 non-clustered index , so is there any way to move all the index to Secondary Filegroup.
View 3 Replies View RelatedI'm working to improve performance on a database I've inherited, and there are several thousand indexes. I've got a list of ones which should definitely exist within the database, and I'm looking to strip out all the others and start fresh, though this list is still quite large (1000 or so).
Is there a way I can remove all the indexes that are not in my list without too much trouble? I.e. without having to manually go through them all individually. The list is currently in a csv file.
I'm looking to either automate the removal of indexes not in the list, or possibly to generate the Create statements for the indexes on the list and simply remove all indexes and then run these statements.
As an aside, when trying to list all indexes in the database, I've found various scripts to do this, but found they all seem to produce differing results. What is the best script to list all indexes?
So I'm reading http://www.sql-server-performance.com/tips/clustered_indexes_p2.aspx and I come across this:
When selecting a column to base your clustered index on, try to avoid columns that are frequently updated. Every time that a column used for a clustered index is modified, all of the non-clustered indexes must also be updated, creating additional overhead. [6.5, 7.0, 2000, 2005] Updated 3-5-2004
Does this mean if I have say a table called Item with a clustered index on a column in it called itemaddeddate, and several non-clustered indexes associated with that table, that if a record gets modified and it's itemaddeddate value changes, that ALL my indexes on that table will get rebuilt? Or is it referring to the table structure changing?
If so does this "pseudocode" example also cause this to occur:
sqlstring="select * from item where itemid=12345"
rs.open sqlstring, etc, etc, etc
rs.Fields("ItemName")="My New Item Name"
rs.Fields("ItemPrice")=1.00
rs.Update
Note I didn't explicitly change the value of rs.fields("ItemAddedDate")...does rs.Fields("ItemAddedDate")=rs.Fields("ItemAddedDate") occur implicitly, which would force the rebuild of all the non-clustered indexes?
I have a requirement to only rebuild the Clustered Indexes in the table ignoring the non clustered indexes as those are taken care of by the Clustered indexes.
In order to do that, I have taken the records based on the fragmentation %.
But unable to come up with a logic to only consider rebuilding the clustered indexes in the table.
create table #fragmentation
(
FragIndexId BigInt Identity(1,1),
--IDENTITY(int, 1, 1) AS FragIndexId,
DBNAME nvarchar(4000),
TableName nvarchar(4000),
[Code] ....
What is the difference please?
View 1 Replies View RelatedI have a scenario like below
Product1
Product2 Product3
Product4 Product5
Product1 1
1 0 0
1
Product2 1
1 0 0
1
Product3 0
0 1 1
0
Product4 0
0 1 1
0
Product5 1
1 0 0
1
How to design tables in SQL Server for the above.
Ok, I'm doing a football database for fixtures and stuff. The problem I am having is that in a fixture, there is both a home, and an away team. The tables as a result are something like this:
-------
Fixture
-------
fix_id
fix_date
fix_played
----
Team
----
tem_id
tem_name
-----------
TeamFixture
-----------
fix_id
tem_id
homeorawayteam
goals
It's not exactly like that, but you get the point. The question is, can I do a fixture query which results in one record per fixture, showing both teams details. The first in a hometeam field and the second in an away team field.
Fixture contains the details about the fixture like date and fixture id and has it been played
Team contains team info like team id, name, associated graphic
TeamFixture is the table which links the fixture to it's home and away team.
TeamFixture exists to prevent a many to many type relationship.
Make sense? Sorry if this turns out to be really easy, just can't get my head around it at the mo!
I would like to create a table called product. My objective is to get list of packages available for each product in data grid view column while selecting each product. Each product may have different packages type (eg:- Nos, CTN, OTR etc). Some product may have two packages and some for 3 packages etc. Quantity in each packages also may be differ ( for eg:- for some CTN may contain 12 nos or in other case 8 nos etc). Prices for each packages also will be different that also need to show. Â How to design the table..Â
Product name  : Â
Nestle milk |
Rainbow milk
packages  :
CTN,OTR, NOs |
CTN, NOs
Price:
50,20,5 |
40,6
(Remarks for your reference):CTN=10nos, OTR=4 nos Â
| CTN=8 Nos
Sir,
1. How do I call the indexes created in SQL server for a table from Front end VB programming ?
2. How can I use SEEK command with ADODB control ?
Please give me some tips & samples
Sundar Raman
Does anyone have the idea why the Indexes with _WA.....(like _WA_Sys_au_fname_07020F21) gets created.I don't how this index got created. I did not create this Index.
My Question is does the system creates these indexes or something else does this.
Thanks
Chak
Is there a way to tell how many indexes exist for an entire database, all I'm looking is for a count or generating a report list.
any help would be appreciated, thank you
At present I have been assigned to create indexes to retrieve the information fast, from the table. The existing table doesn’t have primary key, foreign key and unique constraints but I found to many default indexes already created by the system. I would like to know how this happened? Please inform how to delete these default indexes. Further, inform me other possible ways for the faster retrieval in SQL sever 7.0, if there are any.
I would appreciate if you send me a step by step explanations for the above problems.
Thanks a lot
I have run into a snag on my development server. Queries that are selecting data based on indexed fields in a where clause are using the wrong indexes. They are arbitrarily using the clustered index which isn't in the select at all and causing big performance problems. I can run the same statements on my production server and it runs based on the proper indexes. I used query execution plans to determine that this was infact the case.
I run DBCC Checkdb everynight and it comes back with no errors. I also rebuild the indexes. We also don't receive any other errors inputting or updating data. This sounds like corruption to me but if it's something else I don't want to spend the night restoring from production if there is another reason.
Has anyone encountered this before? Any ideas?
Appreciate it, K.
Is there any way for me to find out when last indexes have been used so that the one I don't need can be dropped.And also the one's that are of no use at all.
I need this as i am trying to dump all duplicated indexe . i know i can do this in ver 7
thanks
when executed sp_help tablename, I get lot of statistics and indexes like the following. Can anyone please tell me how it is generated automatically. as far i know statistics are generated only for primary keys. Can you please tell me what is clustered , hypothetical and the indexes starting with _WA supposed to be. Also there are lot of duplicate stats. Is it Ok to deletes those.
_WA_Sys_is_platinum_0A9D95DB
_WA_Sys_active_0A9D95DB nonclustered, statistics, auto create located on PRIMARY Active
hind_c_33_15 nonclustered, statistics located on
hind_c_37_1 clustered, hypothetical located
Thanks
Raj
Is there a way T-SQL script can find out all indexes built on a set of tables, drop them and periodically ( quarterly as an example ) re-build them ?
Thanks in advance for help.
Ivan
How do you find out indexes ( with column names info ) on a table ?
Thanks in advance.
Ivan
I am on SQL 6.5.
I have a question about speed and indexes. I have a static table (no updates except once a year). I want to be able to search data quickly on one column or many columns. I have created nonclustered indexes on each of the columns I search by. Is there anything else I can do to speed up my queries? Unfortunately all the searches involve using the like operator. I have even broken my table down into 2 smaller tables (Table A ~ 3 million rows, Table B 8 million rows).
All suggestions will be appreciated.
Thanks,
Eric
We have to interduce a new naming convention for the indexes currently available in the user databases.
We also have to drop all the old indexes available in about 250 tables and recreate them all acording to the naming convention we are coming up with.
Can any body suggest any idea.
I thank you guys in advance for your considaration.
hi.
there 2 different queries
1
[MYSQL].... where Cat=@CatID and Date=@Date[/MYSQL]
2
[MYSQL]... where Cat=@CatID and Date=@Date and Salesman=@SID[/MYSQL]
these queries are often used.
my question is about indexes.
should I use two different indexes?
index 1 : Cat,Date
index 2 : Cat,Date,Salesman
or only index 2 is enough ?
I need to alphabetize PART of a union all query, and was told that this may be accomplished with an index. I tried joining two views, but it does not work! I have NO experience with indexes and need some help.
Here is my code:
Select id, country from countries where id = 6 union all Select id, country from countries where id <> 6
I want the country with id 6 (USA) to be the default on a drop down list, then all the other countries listed after it in alphabetical order. Can you do this with an index? If so, how do I proceed?
Thanks!
Ronna
Hi all,
I want to know all indexes in database.
What do I do to get them?
Thanks in advanced,
Thi Nguyen
We recently updated some of the databases from MS Access 2000 to SQL Server 2000. In Access we had columns which were set to Indexed No Duplicates, these were not Primary key fields. Is this possible to set some indexes to prevent duplicates in SQL Server without creating performance issues?
Miranda
Do you have to take the DB offline to create or run indexes in SQL Server 2000??
View 2 Replies View RelatedQ1
The table i have stores max 2000 records. Not sure if i neeed a clustered index for this few records. I guess not.
Q2
For the same table as above. How do you create primary keys if there is not unique records.
Do i create a new column? like newColumnID identity? and create a primary key on this new column? Ok even if i create this newcolumn. I don't think it will improve the retrieving speed cause i'm not selecting this column.
Opinions, ideas?
i am running a stored procedure which has got clustered indexes created after creating table and data is inserted into it after creating clustered indexes. The tables which are meant in this sp is temporary tables and how to gain the performance of a query
View 2 Replies View RelatedI've created indexes for the queries below running select getdate() before and after the query to determine the time. I'm curioius as to how sql server determines and decides how and when to use the indexes for the queries and how the run times of these queries compare. I'm also curious to know what kind of difference there would be on the last two queries as the only difference is the values.
For the last two queries I don't think there would be a difference but hoping that someone would know.
Below are my results:
select count(distinct CustomerID)
from Orders
where Status = 5
SELECT getdate()
go
Create Index Orders_Index On Orders(customerID)
go
SELECT getdate()
select sum(TotalDue)
from Orders
where CustomerID = 11212
select getdate()
go
Create Index Orders_Index On Orders(customerID)
go
select getdate()
select count(distinct AccountNumber)
from Orders
where SalesPersonID = 288
select getdate()
go
Create Index Orders_Index On Orders(salespersonID)
go
select getdate()
select count(distinct AccountNumber)
from Orders
where SalesPersonID = 276
select getdate()
go
Create Index Orders_Index On Orders(salespersonID)
go
select getdate()
where can i find a example on how tobuild a script to reindex all my tablesTksDaveP
View 2 Replies View RelatedI have a very large table (about 200,000 records), but there are only 2 fields in the table only one populated with data. I need to update the 2nd field with the first field's data.
UPDATE Table1
SET field2 = field1
This is taking a really long time to run about 3.5 minutes.
Is this normal? Can I create an index? What can I do to shorten the run time?
Thanks,
Ninel