Here is my create table command
CREATE TABLE EXCLUSIVEITEM(VIEW_ID INTEGER NONCLUSTERED IDENTITY(1,1)PRIMARY KEY,
VIEW_LATEST_REPLY_DATE CLUSTERED INDEX DATETIME)
Is this the way to create one of my columns clustered. The books that I have all use stored procedure I only want to use regular sql commands. Is this possible?
Imagine the following scenario-
Identity(1,1) column ID is primary key and only clustered index key.
Rows will be inserted regularly into this table, hundreds per day.
Queries will be mostly selecting on the most recent records.
In a year, the row will have half a million records or so and only the most recent records will be used. There will be a forward-rolling hot spot, of most recent records.
Does the direction of the ID column in the clustered index make a difference?
I'm thinking no, because query plan will go to that leaf in an index seek regardless of whether it is old or new, "bottom" or "top" of index, especially if the query is very specific on the ID.
I've read this
http://mattadamson.blogspot.com/2005/05/choosing-between-ascending-or.html
but it didn't address (or perhaps didn't need to) this sort of scenario.
Dear All,
i've observed one particular table, one column is having clustered and non clustered index. is it ok? or i need to drop the non clustered column?
the table has 16 columns and at present 8 million records are there. per day approxmately 60000 rows will be getting into the table. it has another 3 non clustered indexes.
please suggest me.
Arnav
Even you learn 1%, Learn it with 100% confidence.
Hi(SQL Server 2000)I have an existing table (t) with a column that is NOT an identity column(t.ID), but it has manually inserted "row numbers". I want to make thiscolumn become an identity column. This column is a key field to othertables, so I want to keep the row numbers that are allready inserted.From the Query Analyzer, how do I do this?Thanks in advance!Regards,Gunnar VøyenliEDB-konsulent asNORWAY
View 3 Replies View RelatedUsers can approach their userprofile on my site using: www.mysite.com/name=peterName is a unique value within my database (db type: nvarchar(50))Now, I have created a clustered index on the username column.However, IMHO its faster to create a clustered index on the (also unique) usercode column since that is of type int.BUT since a user can approach my site based on username I feel that I HAVE to live with this setback in performance....Is that true or is there a better way to solve this issue?
View 1 Replies View RelatedIs it always the best practice to have the partition column also as the column for clustered index?
View 2 Replies View RelatedIs there any way to update a column in a clustered index without incurringthe cost of reordering.Example:Create table TableX (Col1 int,Col2 smalldatetime,Col3 varchar(10))gocreate clustered indext ix_test on tableX (Col2, Col1)goupdate TableX set Col2 = '2004-12-07'-- Yes I specifically left off the criteria to update every row.It would seem to me in this situation that the data types require the samestorage, all rows are being updated in one transaction, and there's no newto reorder since all will be the same.Thanks,Danny
View 2 Replies View RelatedHello there,
I am testing out the performance benefits of utilizing include column(s) to avoid RID lookups and so far it looks very promising. I am able to reduce the cost of the query significantly and execution time is very good. However my non-clustered index is part of the primary key constraint and I am wondering if it is possible to create the include column as part of the primary key. Or do I have to drop the pk constraint and create unique non-clustered index with include column?
Thanks,
Sankar
I have a database where records are Inserted by an external process.
There is no updating or deleting of the data once inserted. The table in
question has a Clustered Index on the Machine_ID (integer) (data is from
manufacturing processes). Each record bears a start and end time. Most
queries involve the Machine, a time span (start time between to points in
time), the Downtime Cause, and the Running Mode.
I want to add an index on the Start Time, the Downtime Cause, and the
Runtime Mode.
My question is: should this new index also contain the Machine_id column
or does the existence of the Clustered Index already on that column negate
its need in the new index?
RC - Dedicated to only creating original mistakes!
I am building three partitioned, clustered column store tables.I was researching whether it was faster to populate a staging table and swap it into the partitioned table or to directly insert into the partitioned table.The first partition for the three tables will have:
Table F: 50M rows, 6 columns wide, partitioned on a date column (1 date, 2 bigint keys, and two varchar columns)
Table D1: 50M rows, 150 columns wide, partitioned on a bigint
Table D2: 19M rows, 300 columns wide, partitioned on a bigint
If build the data that would go into partition 1 in a non partitioned column store, I get these table sizes:
Table F: 476 MB
Table D1: 6,800 MB
Table D2: 5,496 MB
If build the same data directly in the partitioned column store, my table sizes end up being:
Table F: 579 MB
Table D1: 6,800 MB
Table D2: 5,364 MB
That's a 20% difference on Table F, the narrow table.Looking at the row groups, I see 47 identical row groups in partition 1 and the unpartitioned table, but the average "size_in_bytes" is consistently 20% smaller in the unpartitioned table.
I have 5 million rows of table, and going to create Non Clustered Index for Datetime values column. Creating Non clustered Index on Datetime value column will affect performance or not.
View 4 Replies View RelatedWant to check my thinking with you folks...
I have a table with a clustered composite index, consisting of 3 columns, which together form a unique key. For illustration, the columns are C1, C2 & C3.
Counts of distinct values for columns are C1 425, C2 300,000 & C3 4,000,000
C3 is effectively number of seconds since 01/01/1970.
The usage of the table is typically, insert a row, do something else, then update it.
Currently, the index columns are ordered C3,C1,C2. Fill factor of 90%.
My thinking is that this composite index is better ordered C1,C2,C3.
My reasoning is that having C3 as the leading column, biases all the inserts towards one side of the indexes underlying B-tree, causing page splits. Also, there'll be a bunch of "wasted" space across the tree, as the values going into C3 only ever get bigger (like an identity), so the space due to the fill factor in lower values never gets used.
Welcome your thoughts.
I need to find out all the tables in database, which has FK columns and don’t have any Non-clustered index on them.
View 11 Replies View RelatedI've been asked to look at using Clustered Columnstore indexes for one of my tables. The table contains about 5 million records with about 50 columns. The max field size is a NVarchar(MAX) with max field length currently of about 4k characters. It's only about a gigabyte's worth of data. The table is about 50% R/W operations. Currently, we have multiple indexes with no clustered index due to some performance issues that happened in the past. I've been attempting to determine if it's even really worth it to switch over. I feel that the table is still fairly small with minimal columns and don't believe there will be any noticeable improvement over traditional indexing.
View 3 Replies View RelatedI created composite clustered index key based on Gender and Salary columnÂ
The Query executed Successfully and <g class="gr_ gr_135 gr-alert gr_tiny gr_spell undefined ContextualSpelling multiReplace" data-gr-id="135" id="135">i</g>
got composite index key id Gender(-), Salary I <g class="gr_ gr_310 gr-alert gr_gramm undefined Grammar only-ins replaceWithoutSep" data-gr-id="310" id="310">want</g> know why Gender(-) display like this?
And Gender is <g class="gr_ gr_391 gr-alert gr_spell undefined ContextualSpelling ins-del multiReplace" data-gr-id="391" id="391">nvarchar</g>Â (20)Â
I have a table that contains names that are all in upper case, this column is called in many different areas of my web app. I wanted to make the names all lowercase, or with the leading character only capitalized.
How can I make a column within a SQL table lowercase at the SQL server end and not the programming side?
thanks,
Frank
Hai Everyone,
I have a table with data like this
Tran_no Description Debit Credit
1 SW 1000
1 BR1 500
1 BR2 200
1 BR3 300
2 SQ 500
2 BW1 200
2 BW2 200
2 BW3 100
Now what I wanna do this that
Tran_no Val1 Val2 Val3 Val4
1 1000 500 200 300
2 500 200 200 100
Thanks in advance
Nirene
I have a store procedure to create a table temp, populate data from Origin1 table, and then add a new column SSN to temp table, update the SSNs from another table. but the following code gives error, pleaes help!
Create table temp (
....
)
Insert into temp
select * from Origin1
Alter table temp ADD Name int
Update temp
Set SSN = (select SSN from Origin2
where id = Origin.id)
it gives 'Invalid column name: 'SSN'
I am aware that the add new column doesn't take effect until end of the SP, but there must be a way, Thanks for any inputs.
Hi there,
alter table HardwareInventory alter column [HIID] [nvarchar] IDENTITY (1,1) NOT NULL
Getting this error -
Msg 156, Level 15, State 1, Line 2
Incorrect syntax near the keyword 'IDENTITY'.
can someone please suugest
thanks
akhil
if a customer can have up to 10 acounts and each account has a balance,
in customer_account table, the same custID repeats and relates to an
accountID and each account has its own balance.
How to display each customer in ONE row and list his account one next to another ?
for example:
custID, acct#1, acct#1Balance, acct#2, acct#2Balance, acct#3, acct#3Balance
how to do write SQl to achive it ?
This is chanllenging to me...
Your advise is greatly appreciated !
This is what I would like to do...
1. Alter Table Status
Add ConsiderOpenFlag int null
2. UPDATE values...
3. Alter Table Status
Alter ConsiderOpenFlag int not null
Steps 1 and 2 are easy. What I cannot figure out is step three.
I don't want to have a default on that column, though I wouldn't mind adding it and then dropping it later if it would help.
Jonathan
I would like to put a Clustered Index on a date column in a current heap, but one question/concern.This heap every month has thousands of rows deleted and even more added later. How much of an issue will this cause the Clustered Index as far as page splits? I was thinking Fill Factor of 70%.I would normally just test and still will on Dev box, but my Dev box is much smaller than production as far as power.
View 6 Replies View RelatedI have created NONCLUSTERED index on table but my report is taking more time that's why i created columnstore NONCLUSTERED index on the same table but i have one query, if any table have row and column level index(same columns in index) . Which index query will consider.
View 1 Replies View RelatedI am extremely new to database design, and I ran into a problem that I know comes up often, however has many opinions...
Basically I have a table that is going to have 50+ columns. The natural key on this table is actually 8 columns wide, 4 of them being Varchar columns by default. (varchar(50)'s).
I have added an identity column, (1,1) to the table, however I put the clustered index on the 8 natural keys... My plan is to rebuild the clustered index once nightly when the system isn't in use (after 7 pm).
I know others would say it would be better to have the clustered key on the 1,1 column and then add indexes on the other 8 fields... However I don't quite understand why honestly...
Every single query against this table will use the 8 columns, and will NOT use the Identity column (1,1) because they are calls from other systems that do not know the Identity column....
Therefore if your database is set up for query speed, and every single query has to have a value for 8 columns to get a valid result, does it make sense to put a clustered index over the 8 columns?
If not why? Why is putting a clustered index on an identity column (that will literally never be used in a query) a better solution?
I need to generate weekly report for data usage for my c drive and d drive.the graph should be likefor a particuluar date, I want to display graph like this. even if I change secondary axis, my c: drive used and free space not coming in single column. it comes like c: drive used space, on top of it d: drive used space and in adjacent column  c: drive free space, on top of it d: drive free space.I don't want to add two category one for date and another for driver names.
View 6 Replies View RelatedHello, I have a table (publication) that has a primary key pubID which is an identity specification. This ID already has relationships to other tables.
I am having problems trying to make one of the other columns in the same table to auto generate. This column (bibNumber) is not related to any other table. All i want to do is when i create a new record in the table, auto generate a number for this column bibNumber.
How can i do this?
I am using sql server express 2005
Regards
Hello, everyone:
I have a table with an indentity column as first column. At beginning it is continue such as 0-50. I delete last 20 columns by hand. The 0-31 is left. When the new data is inserted, I hope the new indentity column begin from 32. How to do that? Now the indentity column begin from 51 as the new data is inserted.
Thanks a lot
ZYT
I have a table with a TEXT column that allows nulls.
Now I need to change it, and make it NOT NULL, but I Can't
ALTER TABLE BUSINESS_UNIT_LANG
alter column VISION text not null
And I get:
Server: Msg 4928, Level 16, State 1, Line 1
Cannot alter column 'VISION' because it is 'text'.
Is it impossible to make a text column NOT NULL when it accepts NULLS ?
All rows and columns are populated, in consequence there isn't any col with null values
Any idea?
Thanks!
when we display hierarchies, we'd like the user to have the option of expanding a column for wider viewing, perhaps by dragging a border. Is this possible?
View 3 Replies View RelatedI have a database in which I have some tables in which I have implemented Clustered columnstore Index. How to find the fragmentation levels of all these indexes via a single T-SQl script
View 3 Replies View RelatedHow can we get the list of clustered columnstore index in a database in sql server 2014
View 3 Replies View RelatedWe are going to use SQL Sever change tracking. The problem is that some of our tables, which are to be tracked, have no primary keys. There are only unique clustered indexes. The question is what is the best way to turn on change tracking for these tables in our circumstances.
View 4 Replies View RelatedI desire to have a clustered index on a column other than the Primary Key. I have a few junction tables that I may want to alter, create table, or ...
I have practiced with an example table that is not really a junction table. It is just a table I decided to use for practice. When I execute the script, it seems to do everything I expect. For instance, there are not any constraints but there are indexes. The PK is the correct column.
CREATE TABLE [dbo].[tblNotificationMgr](
[NotificationMgrKey] [int] IDENTITY(1,1) NOT NULL,
[ContactKey] [int] NOT NULL,
[EventTypeEnum] [tinyint] NOT NULL,
[code]....