SQL 2012 :: Disadvantage Of Having Too Many Indexes
Aug 6, 2015Any disadvantage of having too many indexes?
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DB Engine :: Disadvantage Of Creating A Table In Separate Filegroup
Aug 17, 2015We have a table that we are using for inserts for every 2mins and it is a very large table.
I am panning to add this table to a separate file and file-group, so that i can keep this file in separate drive.And it will restore files level.
Is there any disadvantage if we create this table in this way.
SQL 2012 :: Create New Indexes
May 24, 20141)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.
SQL 2012 :: Filtered Indexes In Server
Aug 14, 2014What 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
SQL 2012 :: How Indexes Allocated On Pages
Nov 6, 2014How 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 RelatedSQL Server 2012 :: Indexes Based On A Query?
Aug 18, 2014trying 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].....
SQL 2012 :: Identify Unused Indexes In Table
Jan 15, 2015How 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 RelatedSQL Server 2012 :: Nonclustered Indexes On Bit Flags
Mar 24, 2015I 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 ?
SQL 2012 :: Maintain Indexes When AlwaysON Is In Place
Aug 4, 2015I 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.
SQL 2012 :: Disabling Indexes For Load Performance?
Sep 22, 2015I'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?
SQL Server 2012 :: Rule Of Thumb When To Disable Indexes?
Jun 19, 2014It'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...
SQL Server 2012 :: Script To Reorganize All Enabled Indexes
Jul 30, 2015My 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?
SQL 2012 :: Way To Remove All Indexes From A Table With One Single Command
Sep 29, 2015IS 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 RelatedSQL 2012 :: Performance Limit On Number Of Indexes Per Table / Database
Oct 1, 2014Is 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 RelatedSQL Server 2012 :: How To Generate Index Creation Scripts (many Indexes)
Jun 24, 2015Script 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.
SQL 2012 :: Maintenance Plan - Rebuild Indexes Only Run If Required Or Open Fires On Schedule?
Aug 23, 2015Normally 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 RelatedRemoval Of Selected Indexes / Script Index Create For List Of Indexes
Jul 1, 2014I'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?
SQL Server 2012 :: Why Indexes On Table Slow Down DML Operation On Table
Mar 7, 2014Why the Indexes on table slow down the DML operation on table, what is the exact reason?
View 5 Replies View RelatedSQL 2012 :: Remember Definitions Of Clustered And Non Clustered Indexes?
Nov 24, 2014What is the easiest way to remember the definitions of clustered and non clustered indexes.
View 9 Replies View RelatedA Question About Clustered Indexes Forcing Rebuild Of Non-clustered Indexes.
Sep 18, 2007So 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?
SQL Server 2008 :: Logic To Rebuild Only Clustered Indexes / Skipping To Rebuild Non Clustered Indexes In Same Table
Jun 25, 2015I 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] ....
Indexes Vs Clustered Indexes
Sep 17, 2006What is the difference please?
View 1 Replies View RelatedIndexes
Jul 31, 2002Sir,
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
Indexes
Jul 23, 2001Does 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
DB Indexes
Jul 27, 2000Is 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
Indexes
Sep 13, 2000At 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
Indexes Not Being Used
Nov 20, 2000I 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.
6.5 Indexes
Jan 10, 2001Is 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
Indexes
Feb 5, 2000when 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
Indexes
Mar 2, 2001Is 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
Indexes
Mar 5, 2001How do you find out indexes ( with column names info ) on a table ?
Thanks in advance.
Ivan
Indexes!
Jun 20, 2001I 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
The Indexes
Nov 12, 1998We 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.