1)When we create Indexes, key columns are the columns that use in where clause and included columns are the columns that can be used in the select list and on join clause column.
2) I am thinking that we have to create new Index, only if we found at least 50 msec time save.
I'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?
When creating the indexes on the table, SQL 7.0 also created some type of system indexes ( ex. _WA_Sys_curr_int_rate_2C88998B nonclustered, statistics, auto create located on PRIMARY, etc. ). I want to know how can I clear up these system indexes.
View 1 Replies View RelatedSlayer writes "Probably a really lame question but in the absence of our DBA I have been asked to create a couple of indexes on a table. No problem with that, just need to know if this is a safe operation whilst users are using the database.
Thanks for your help"
Hello,
A few months ago, the company I work for switched to SQL 7.0 from 6.5. All is running fine but recently I noticed that we have a ton of indexes on each table that start like this: _WA_SYS_....0B679CE2 (here are some specific examples: _WA_SYS_PRODUCT_LINE_0B679CE2, _WA_SYS_RMA_DISPOSITION_0B679CE2)
Did SQL 7.0 do this? If so why? What is it trying to do? Why doesn't it use current indexes (clustered and non-clustered)? Why don't they get Fragmented like User defined indexes? I have a lot of questions associated with this if someone can explain it.
Tech Net, MSDN, BOL and other manual resources don't mention anything about it. At least I haven't found anything on it and I have spent some time looking.
Please help if you can.
Troy
I found out how to create clustered index using TSQL, but how can you create clustered index and manage indexes using SQL Server Management Studio?
Thanks
Goldmember
Hi,I have a new job. It needs to drop and re-create (by insert) a tableevery night. The table contains approximately 3,000,000 (and growing)records. The insert is fine, runs in 2 minutes. The problem is thatwhen I create the indexes on the table, it is taking 15-20 minutes.There is one clustered index and 11 non-clustered. This is a lookuptable that takes many different paremeters, so it really needs theindexes for the user interface to run efficiently. However, thedatabase owners aren't keen on a job taking 20 minutes to run everynight.Any ideas?
View 5 Replies View RelatedFirst, I'd like some help stablishing if it's a good idea or not what I'm thinking, and second is what would be the easyist way to achive the result.
Background. We have a multicompany ERP system (200GB, 200+ tables). All data tables have a companyid, counter1id, counter2id, fields. Each table has a primary clusterd index on these fields in that order. And also has multiple other indexes that usually include companyid filed first. ( Note we have 10 companies, ids are 1..10, companies 2 and 5 are the most active, inserts, selects ). MY GUESS IS THAT THIS IS VERY BAD HAVING COMPANYID FIRST. AM I CORRECT? LEADS TO AL LOT OF FRAGMENTATION? VERY BAD TO FIND DATA ON THE INDEXES?
I want to re-create all my indexes and have them counter2id, companyid, counter2id. ( counter1id is a counter for each company, and counter2id is a global counter like identity ) GOOD OR BAD IDEA?
Since I have hundreds of indexes what is the correct procedure? I was thinking on scripting the database, then dropping all indexes, then recreate clustered indexes, then recreate other indexes. Do I have to take care of anything else foreing relationships, etc.
Hi everyone,
I know that statistics called _WA_... are created on tables when auto create statistics is set on a database. Is this an indication that queries against the table would perform better if indexes were created on the columns in question? (The tables I'm interested in optimising are used equally for transactional querying and reporting)
Thanks for any replies!
Les
I am new to writing SQL code and I read that you can use ALTER statements to create an index for a table. How would I go about doing that? Everything that I have tried in Query Analyzer comes up with an error.
Any help is appreciated.
is there a function that i can use in a store procedure that allow me to create an Indexes/Keys Property
thanx
With help of others on this group, I've been learning and researchingabout indexes; an area I neglected.I see I can specify which filegroup I wish to create an index, whichthe default is Primary.I have more than one drive in my SQL server where I put data and logson their own logical raid groups.My databases are SIMPLE, so they dont use much, if any logs (none as Iunderstand).I was thinking of adding an additional file to my database and use itsolely for the indexes.Any thoughts?SQL Server 2005 Enterprise x64 SP28 disk SAS Raid 1+0 w/ 512mb ram w/ battery backup.Thanks,Rob
View 2 Replies View RelatedI have a pretty large database that has tables that will contain millions of rows of records. I will predominantly be using Views just to select the data. (I will not be performing any updates or inserts). I propose creating indexes on the views. My question is - if I create indexes on my views, do I have to create them on the tables as well? Is it good practice to create indexes on tables by default even if I am not going to be performing select statements directly on my tables but via my indexed views? Any advice is appreciated.
Thanks
Ran
Hi,How Can I create a case sensitive unique index so that A1 and a1 are treatedas different ?I dont mind if I have to make a global DB change.Steve
View 1 Replies View RelatedI use Indexes Fundamentals of Microsoft SQL Server - Lesson 30: Indexes in the website of URL... to learn the basic things of Indexes. In my SQL Server 2012 Management Studio (SSMS2012), I executed the following code..
-- scFTX_CreateTableEmployees.sql
-- saved in C:/Documents/SQLServerIndexes_downloadCode
-- 26 May 2015 10:52 AM
USE ScottChangDB;
GO
CREATE TABLE Employees
[code]....
Where the SCHEMA and the index 'IX_Employees are located in the Object Explorer of the database "ScottChangDB" of my SSMS2012.
Any disadvantage of having too many indexes?
View 3 Replies View RelatedHow to script all the PK/FK/constrainnts/indexes with create and drop statements?
As you know, we can't script 'drop statements' for primary keys etc..
Any help in giving me a script which does all the above is greatley appreciated..
Thanks,
Di.
For large databases is it a good idea to create indexes for fields that are used in Where statements? Does that improve performance and reduce overhead?
View 4 Replies View RelatedWhat are driving criteria for creating filtered indexes on SQL server. I am trying to analyze the index stats through DMV,histogram and have to analyze if the filtered indexes should be created on tables. This exercise has to be done for all the transaction tables on the database. What are the approaches I should be looking on?
There was a deadlock on the DB because of huge writes on one of the big tables. Having filtered index on this table for the effected column would reduce the time taken for write operations. Hence we are looking for creating filtered indexes appropriately
How Indexes are allocates on pages? And If a CREATE INDEX Statement Executed on a query Window, Query processor meets and executes these query. However it was meet, who decides to separate indexes onto pages? Storage Engine or Query Processor(Query Optimizer)? Does it work like UPDATE-Statements in Query Optimizer?
View 4 Replies View Relatedtrying to create indexes on two tables:
SF_Affiliate_Customer
SF_Affiliate_Customer_Account
on which the following query is based. I need to build indexes so that the query will perform better. Now its very slow..
SELECT DISTINCT C.[afflt_cust_natl_key],[as_of_dt]
FROM [dbo].[SF_Affiliate_Customer] C
WHERE
( [afflt_intrnl_cust_ind] = 'N'
AND [afflt_empl_ind] = 'N'
AND (ISNULL([phys_addr_st_rgn_cd],'')<>'CA' AND ISNULL([mlng_addr_st_rgn_cd],'')<>'CA')
)AND
[code].....
How to find if there is a query that can be written on DMV's which will be able to retrieve the indexes that are not being used in a table.
View 2 Replies View RelatedI have a scenario where I have 3 columns and all 3 of them are used in the where clauses of simple queries or ones having joins .
TABLE(
Column1 int
FLAG1 bit
FLAG2 bit
)
Sample queries :
Select * from TABLE where FLAG1 =1 and FLAG2 =0
(Any combination of these flags)
Select * from TABLE inner join SOMEOTHERTABLE on
TABLE.Column1 = SOMEOTHERTABLE .Column1
where FLAG1 =1 and FLAG2 =0
( any join and combination of flags)
Questions :
What would be the best nonclustered index strategy :
Column1 as the index key including FLAG1 and FLAG2
or
Column1,FLAG1 and FLAG2 in the index key
Points to note :
The queries are part of an ETL process and are used to track new records vs old records. The Flags switch states within the same job . So if we are creating an index on all 3 columns, the index has to be reorganized more than once based on the flag states. If we keep them in the include list , then its only about updating the leaf data with the latest flag values.
On the other hand, an index on all 3 columns will result in an index Seek alone , where as for the included list , there will be an index seek and a predicate .
Does the predicate cause more overhead than reorganizing the index or is it the opposite ?
I have a new cluster (2 sync, 2 async) with about 50 databases going from 1 to 200gb ( all of the objects are compressed).That at sql server 2012, sp1 CU7.I have several drives for logs with 200gb of space in there...I am having issues at rebuilding indexes on this env, ie, I have a table with the clustered index heavily fragmented (~80%), and the table has about 60gb of data, uncompressed that should be about 160gb.
The index rebuild is creating a log file big enough as to consume all the space that I have for logs, and that is only 1 table, so for sure my old process to maintain indexes (ola.hallengren code) won't work on this scenario.
I'm trying to improve the loading of some tables with large amounts of data that forms part of an ETL. I was going to try removing any indexes before the inserting to speed up the process, but I had some questions on whether or not I should include the clustered index (assuming one exists).
I was originally planning on including a step to disable all indexes on the destination table using the following:
ALTER INDEX ALL ON MyTable DISABLE
Once the load had finished I'd simply rebuild all the indexes.
should I simply disable the non-clustered indexes?
It's often said or done that when inserting or updating into a 'large' table that disabling the non-clustered indexes can is needed for performance.
Now I know the obvious way to find out if this is best or not is by testing the different options. I was wondering if there was a rule of thumb to this?
Say you have a table with half a billion rows and 4 non-clustered indexes and are only updating half a million rows then sometimes disabling every night and re-enabling can take way more time than the actual update. Haven't found an articles advising to disable them when a table is over X rows and you are updating Y% of them...
My index reorganise maintenance plan fails partly due to the disabled indexes
Executing the query "ALTER INDEX [I_ModelSecurityCommon_RECID] ON [dbo]...
" failed with the following error: "Cannot perform the specified operation on disabled index 'I_ModelSecurityCommon_RECID' on table 'dbo. Model SecurityCommon'.". Possible failure reasons: Problems with the query, "ResultSet" property not set correctly, parameters not set correctly, or connection not established correctly.
I don't want to delete the indexes as they are standard indexes that where on the DB from install.. any script that will reorganise all enabled indexes? and also to rebuild?
IS there a way to remove all indexes from a table with one single command ( without having to know what the index name is ) ;
View 2 Replies View RelatedIs there a performance limit on the number of indexes per table / database ? With Filtered indexes there appear to be many more opportunities for more finely defined, and therefore smaller indexes resulting in many more indexes on a single table.
View 4 Replies View RelatedScript they use to generate indexes in SQL 2005.
I have 2 databases on a separate instance. I want to script out all indexes from database1 then execute it on database2.
How to accomplish this task efficiently.
Normally we use rebuild, reorganize indexes when it is required, I used a SQL job using maintenance plan to run daily and rebuild, reorganize indexes and update statistics but I do not know if it runs either they are required or not. Should this plan automatically execute the build upon required indexes to be rebuild or it fires either they are required to be executed or not.
View 2 Replies View RelatedWhy the Indexes on table slow down the DML operation on table, what is the exact reason?
View 5 Replies View RelatedWhat is the easiest way to remember the definitions of clustered and non clustered indexes.
View 9 Replies View Related