Transact SQL :: Difference Between Index And Primary Key
Aug 10, 2015What is the difference between the Index and the Primary Key?
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Transact SQL :: Any Reason For Difference In Order Of Columns Between Index Of Constraint And Its Statistics Definition?
Sep 5, 2015I am really puzzled by an apparent difference between table index key column order and its statistics order. I was under understanding that index statistics mirror index definition. However, in my db 2470 index ordinal definitions match statistics definition but 66 do not. I also can reproduce such discrepancy in 2008 R2, 2012 and 2014.
As per definition,
stats_column_id
int
1-based ordinal within set of stats columns
This script duplicates this for me.
BEGIN TRAN
GO
use tempdb
GO
CREATE TABLE [dbo].[ItemProperties](
[itmID] [int] NOT NULL,
[cpID] [smallint] NOT NULL,
[ipuID] [tinyint] NOT NULL,
[Code] ....
The result I get is this:
object_id stats_name
stats_column_list
1525580473 PK_ItemProperties_itmID_ipuID_cpID itmID, cpID, ipuID,
and
object_id index_name
index_column_list
1525580473 PK_ItemProperties_itmID_ipuID_cpID itmID, ipuID, cpID,
Also a query I used to discover this in my db is:
WITH stat AS
(
SELECT
s.object_id
,s.name as stats_name
,(
SELECT
c.name + ', ' as [data()]
FROM sys.stats_columns as sc
[Code] .....
Transact SQL :: Dropping Clustered Index On Primary Key Which Is In Replication?
Oct 2, 2015I am trying to drop a primary key on column LID and then create a clustered index on a new identity column ID and then add the primary key back on the LID. I am not able to do so due the table being in replication. here is the error:
Cannot alter the table '' because it is being published for replication.
How do I get past the error and create the Clustered Index on ID column in both publisher and subscriber?
Data Warehousing :: Difference Between Primary Key With Clustered And Non-clustered Index
Jul 19, 2013I have created two tables. table one has the following fields,
Id -> unique clustered index.
table two has the following fields,
Tid -> unique clustered index
Id -> foreign key of table one(id).
Now I have created primary key for the table one column 'id'. It's created as "nonclustered, unique, primary key located on PRIMARY". Primary key create clustered index default. since unique clustered index existed in table one, it has created "Nonclustered primary key".
My Question is, What is the difference between "clustered, unique, primary key" and "nonclustered, unique, primary key"? Is there any performance impact between these?
Difference Between Index Seek && Index Scan && Index Lookup Operations?
Oct 20, 2006please explain the differences btween this logical & phisicall operations that we can see therir graphical icons in execution plan tab in Management Studio
thank you in advance
Transact SQL :: Difference Between Cluster And Non-cluster Index
Jul 26, 2015Wanted to know about difference between cluster and non cluster index with example.
When to use cluster index and non cluster index .
Difference Between A Primary Key And A Unique Key?
Jan 19, 2008 hello all sorry m asking Database Question .. m talking about SQL SERVER 2005 but i have bit confusion... what difference between a
primary key and a unique key? if m not wrong then primary key doesn't allow NULLs, but
unique key allows NULLs but in many searches comes that primary key doesn't allow NULLs, but
unique key allows one NULL only. what this means 'one NULL only'?? according to my practical we can give more then 1 nulls... plz clear this point???
Difference Between Multiple Primary And Secondary Files..
Apr 10, 2006Hi all..!If I want to split an SQL DB into several physical files (as its 500GBdisk ran out of space, won't even run shrinks any more, and we boughtanother 500GB disk to add to the PC)then what is the difference between:Adding another File to the primary group which will reside on the newgroup;Adding another file in another group.We do not want to set any db objects (Tables, indexes)to a secondary file, as this will involve lengthy data movingoperations. We would like the DB to continue working from where it isutilizing the added space in a contigous (striped) manner.Will striping occur in both cases? as I understand striping it meansthat our stuck SQL Server will awake back to life as it will now have500GB more data for its DB, even though we haven't set any of itsobjects (tables, indexes) to explicitly use the secondary NDF file onthe new disk?or will it only utilize the new space if we set some objects to resideon that NDF?for example if we run large queries which crash now (due to lack ofspace) when we add the second drive will they start to work as theprocess will grow striped from the full drive to the new drive, even ifall the queries' source tables are all still set to the old drive?Thanks for any replies?
View 1 Replies View RelatedWhat's The Difference? Unque Constraint And Unique Index, Etc.?
Jul 23, 2005All,What's the difference between a unique contraint and unique?sementically, if you want a column contain unique values, it is acontraint. And an index is for searching/sort. The questions are:1. Does a unique constraint interally use unique index?2. If Yes to #1, I DO NOT need to create an index for search/sortpurpose, right?3. If Yes to #2, What's better?4. Also for Primary Key column, it is actually a special uniquecontraint. Not need to create index on PK column for searching/sorting,correct?5. Also for FK contraint, no need to create an index forsearching/sorting?ThanksJohn
View 4 Replies View RelatedASC/DESC Clustered Index - Will It Make A Difference In This Scenario?
Sep 7, 2007Imagine 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.
Index With Primary Key
Jun 1, 2008Hello there,I got a problem when I'm trying to Index a table with PrimaryKeyMy code so far:1 'Create my table2 nonqueryCommand.CommandText = "CREATE TABLE UpdateHistory (id integer IDENTITY(1,1) NOT NULL, version varchar(50) NOT NULL)"3 Console.WriteLine(nonqueryCommand.CommandText)4 Session("Tables") = Session("Tables") + "Number of Rows Affected with table UpdateHistory is: " + nonqueryCommand.ExecuteNonQuery().ToString + "<br />"5 6 'Set column id to Primary Key7 nonqueryCommand.CommandText = "CREATE INDEX idxid ON UpdateHistory (id) With PRIMARY"8 Console.WriteLine(nonqueryCommand.CommandText)9 Session("Tables") = Session("Tables") + "PrimaryKEY - Number of Rows Affected with table UpdateHistory is: " + nonqueryCommand.ExecuteNonQuery().ToString + "<br />"
I do get this error:System.Data.SqlClient.SqlException: Incorrect syntax near the keyword 'PRIMARY'. at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection) at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection) at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj) at System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj) at System.Data.SqlClient.SqlCommand.RunExecuteNonQueryTds(String methodName, Boolean async) at System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(DbAsyncResult result, String methodName, Boolean sendToPipe) at System.Data.SqlClient.SqlCommand.ExecuteNonQuery() at updates_100_2.Page_Init(Object sender, EventArgs e) in http://server//admin/NewSystem/1.0.0/2.aspx.vb:line 163Note: Line 163 is 9 here..
Anyone who can see what I'm doing wrong?
Primary Key Index?
May 17, 1999Running SQL 6.5, using ActiveX controls(ADO and Datagrid),NT 4.0. All SP's
are current.
I lose the ability to get distinct values with a client-side cursor
after I set up a primary key. Select distinct works perfect before the
primary key creates an index. Any ideas?
Index And Primary Key
Dec 9, 2004By defining a numeric field in table as primary key, will the table be indexed on that particular field?
View 14 Replies View RelatedPrimary Key Index
Apr 1, 2004Hi,
I have a table in my SQL 2000 database called utContact, this has a primary called ContactID (int, idenitity), by default this should have a clustered index on it, but when I go to view the indexes on the table it shows the primary key index as non clustered.
How can this be?
SQL server also will not let me change the index to clustered, but I need to as this is causing a lot of table scans in query execution plans.
Any help or advice on this matter would be greatly appreciated.
Cheers
Transact SQL :: Difference Between Exist And In?
Aug 24, 2015select count(cars.carid)
from
Cars left
join
RentalOrders
on
cars.CarID=RentalOrders.CarRef
where carid not
in(selectRentalOrders.CarRef
from
RentalOrders)
when I wrote this above-query for sofiacarrental_v2.2 it shows 30 in the result but when I changed it this query to that:
select count(cars.carid)
from
Cars left
join
RentalOrders
on
cars.CarID=RentalOrders.CarRef
where not exists
(select
RentalOrders.CarRef
from
RentalOrders)
I replaced not in with not exists it showed 0 in the result.there is any point in term of using them or I made a mistake in the second query?
Change Primary Index Value
Oct 28, 2006Is there any way to change the value of a primary key value?
View 10 Replies View RelatedPrimary Key With Cluster Index
Oct 9, 2007Hi All,
One of my client having 1 million(nearly) records in a table.
I defined the table as below
1) Created table with one col(we can name it as "ID") having IDENTITY
2) Using "alter table", I created CLUSTERED PRIMARY KEY Constraint on Same field (ID)
3) The Primary key having 2 ref with another 2 tables
Now the issue is when we create or define a primary key (With Clustered Option) automatically cluster Index will be created on defined table
As such table having huge data whenever any updation or insertion against that particular table taking huge amount of time, because the cluster Index trying re-paging whole data. Because of re-paging each and every time "Transaction Log also growing in huge" (database is in full recovery mode and client wants in same mode only)
Data partitioning not posible because whole data related and current live data
I tried following options with vain
1) To Clear transaction log I suggested to take regular log backup's
2) I tried to drop cluster index and tried to implement non clustered index
Drop and re-create index is take taking huge amount of time
Even in this process I have to Re_Index remaining Index's also
Pls give me any other solution or suggestion in this regard
with Thanks & Regards
Bhaskara
Help Me Please Error Index - Primary Key
Apr 9, 2008'PXQ_2' table
- Unable to delete index 'PK_PXQ'.
ODBC error: [Microsoft][ODBC SQL Server Driver][SQL Server]I/O error (bad page ID) detected during read at offset 0x0000000102e000 in file 'D:MSSQL2000MSSQLxxx.mdf'.
I can't drop Primary Key. How to fix this problem?
Hardware(HDD) no error. I test oke?
Please help me.
-= MIB =-
Primary Key Without Clustered Index
Jan 28, 2008Dear All,
i've read one article that with some option, we can avoid creating clustered index on the primary key column. is ti possible?
how can we create a primary key without allowing sql server to create automaticaly a clustered index?
Vinod
Even you learn 1%, Learn it with 100% confidence.
Primary Key With Non-clustered Index
Dec 11, 2007Dear all,
I want to keep certain archive data in certain tables. One such table is currently about 190 GB in size. It has a primary key with clustered index and three non-clustered indexes. The type of queries fired are strictly selects (daily) and inserts (only monthly).
Question: Is it advisable to have a non-clustered index on the primary key column?.....I am finding that the insert performance is getting hurt due to presence of clustered index on such a large table (190 GB).
Let me know your views.
Regards,
Chetan
Rda Dropping Primary Key Index
May 2, 2007I am using RDA to download a tables
I use TrackingOffWithIndexes
the issue is that when I download a small set of data the primary key index is there
when I download a larger set. the index gets dropped (no error) just slowness when querying the table
the max database size is set to 1024mb and the temp database size is set to 1024mb
the actual db size (with the missing index) is 262 mb... lot's of room left!
when I try to create the index manually after the download in sql server management studio I get this error:
Not enough storage is available to complete this operation
I am using 2GB sd cards and nothing else is on the card.
any ideas?
Regards,
eric [at] westgen com
Index Statistics And A Primary Key
Sep 5, 2007Hi
I have a question regarding updating statistics for a primary key.
Background: An update statistics with fullscan is sometimes taking 30 minutes - the table is 80 million rows, with only 4 columns. The table is truncated, and then 80 million rows inserted all in one go.
Now why the update stats is taking that long is another question (I have no idea - any thoughts?), but my question is; Since you can't disable the "not automatically recompute statistics" option for a primary key, and you would think it would be imperitive for the stats to be kept up to date for a PK for inserts.... does this mean the stats would be kept up to date? and an update stat with fullscan isn't required?
Hope someone can help
Thanks
James
Transact SQL :: Difference Between Data With Group By
Jul 28, 2015I have a SQL table like this
Events time endTime
Tram 2014-11-28 12:35:50.390 2014-11-28 12:43:19.120
Re-Entry 2014-11-28 12:43:19.120 2014-11-28 12:56:07.040
Tram 2014-11-28 12:56:07.040 2014-11-28 13:15:25.060 // EndDate Before dump
Dump 2014-11-28 13:15:25.060 2014-11-28 13:50:07.233
Tram 2014-11-28 13:50:07.233 2014-11-28 13:55:17.473
Load 2014-11-28 13:55:17.473 2014-11-28 14:06:55.063
Tram 2014-11-28 14:06:55.063 2014-11-28 14:37:12.100
Dump 2014-11-28 14:37:12.100 2014-11-28 14:37:12.100
I want to calculate the Difference between 2 dates like endtime before Dump -time..I am expecting output like this
ROW1 ROW2
1 00:39:34
2 23:12:55
You can find the details in SQL Fiddle here.
Transact SQL :: Query On Running Value (difference)
Jun 18, 2015I have a table that will be loaded over night everyday and I need to write a query on running value difference ?
List of Columns (ID, Branch ,Group, Date, Value)
ID Branch Group Date Value
1 A C 2015-06-01 10
2 A C 2015-06-02 15
3 A C 2015-06-03 25
4 A C 2015-06-04 20
5 B D 2015-06-01 20
6 B D 2015-06-02 25
7 B D 2015-06-03 10
8 B D 2015-06-04 20
I want the Output like below with a Running value difference in comparison to previous day.
ID Branch Group Date Value Running Value
1 A C 2015-06-01 10 10
2 A C 2015-06-02 15 05
3 A C 2015-06-03 25 10
4 A C 2015-06-04 20 -5
5 B D 2015-06-01 20 20
6 B D 2015-06-02 25 05
7 B D 2015-06-03 10 -15
8 B D 2015-06-04 20 10
Basically I need to compare the previous day and show the difference. How can I do this in SQL 2008 r2?
Creating Primary INDEX Problem
May 30, 2000I created table and also I define the primary key its okay
but when I generate the SQL script for that table its not
creating the primary key
CREATE TABLE [dbo].[table1] (
[emp_id] [int] NOT NULL ,
[emp_name] [char] (25) NULL ,
[emp_address] [nvarchar] (50) NULL
) ON [PRIMARY]
GO
PS: I want to use emp_id as primary key but its not defined in the sql script
Thankx a lot
Sysindexes - How To Distinguish Primary Key Index
Apr 22, 2003indid =1 works, is this the correct way
View 3 Replies View RelatedUnique Index On X Columns But Not Primary Key
Feb 23, 2006my table :
CREATE TABLE [dbo].[users] (
[ID] [int] NOT NULL ,
[A1] [nvarchar] (100) NULL ,
[A2] [nvarchar] (100) NULL ,
[A3] [nvarchar] (100) NULL
) ON [PRIMARY]
i must keep ID columns as primary key
ALTER TABLE [dbo].[users] WITH NOCHECK ADD
CONSTRAINT [PK_users] PRIMARY KEY CLUSTERED
(
[ID]
) ON [PRIMARY]
but now A1+A2 must be unique
how can i do it ?
thank you
Create Table + Index + Primary
Dec 17, 2006for MS SQL 2000
how can I do this in one time (into the CREATE TABLE)
CREATE TABLE [dbo].[Users] (
[id_Users] [int] NOT NULL ,
[Name] [nvarchar] (100) NULL,
[Serial] [nvarchar] (100) NULL,
) ON [PRIMARY]
ALTER TABLE [dbo].[Users] WITH NOCHECK ADD
CONSTRAINT [PK_Users] PRIMARY KEY CLUSTERED
(
[id_Users]
) ON [PRIMARY]
CREATE UNIQUE INDEX [IX_Users] ON [Users]([Serial]) ON [PRIMARY]
and that one
CREATE TABLE [dbo].[UsersExtra] (
[id_Users] [int] NOT NULL
) ON [PRIMARY]
ALTER TABLE [dbo].[UsersExtra] ADD
CONSTRAINT [FK_UsersExtra_Users] FOREIGN KEY
(
[id_Users]
) REFERENCES [Users] (
[id_Users]
) ON DELETE CASCADE
thank you
SQL Server Takes Index Instead Of Primary Key
Aug 10, 2007Hallo,
Following scenario:
Table1 with column: Year char(4), Quarter char(1), ID decimal(10,0), Hits int
PK_table1 on Year,Quarter,Hits
If i do a "Select Year From table1 group by Year", the executionplan looks like
select year from dbo.table1 group by year110NULLNULL1NULL4NULLNULLNULL86,21644NULLNULLSELECT0NULL
|--Stream Aggregate(GROUP BY:([Testdb].[dbo].[Table1].[YEAR]))121Stream AggregateAggregateGROUP BY:([Testdb].[dbo].[Table1].[YEAR])NULL406E-061186,21644[Testdb].[dbo].[Table1].[YEAR]NULLPLAN_ROW01
|--Parallelism(Gather Streams, ORDER BY:([Testdb].[dbo].[Table1].[YEAR] ASC))132ParallelismGather StreamsORDER BY:([Testdb].[dbo].[Table1].[YEAR] ASC)NULL800,028547491186,21643[Testdb].[dbo].[Table1].[YEAR]NULLPLAN_ROW11
|--Stream Aggregate(GROUP BY:([Testdb].[dbo].[Table1].[YEAR]))143Stream AggregateAggregateGROUP BY:([Testdb].[dbo].[Table1].[YEAR])NULL803,6248431186,18788[Testdb].[dbo].[Table1].[YEAR]NULLPLAN_ROW11
|--Clustered Index Scan(OBJECT:([Testdb].[dbo].[Table1].[PK_Table1]), ORDERED FORWARD)154Clustered Index ScanClustered Index ScanOBJECT:([Testdb].[dbo].[Table1].[PK_Table1]), ORDERED FORWARD[Testdb].[dbo].[Table1].[YEAR]1,449936E+0774,588317,9747291182,56304[Testdb].[dbo].[Table1].[YEAR]NULLPLAN_ROW11
Now, with another index IX_Hits on hits and the same sql query, sql server now takes IX_Hits instead of PK_table1. And, it takes more time. Any idea why?
select Year from dbo.table1 group by Year110NULLNULL1NULL4NULLNULLNULL85,54985NULLNULLSELECT0NULL
|--Sort(DISTINCT ORDER BY:([Testdb].[dbo].[Table1].[YEAR] ASC))121SortDistinct SortDISTINCT ORDER BY:([Testdb].[dbo].[Table1].[YEAR] ASC)NULL40,011261260,0001374511185,54985[Testdb].[dbo].[Table1].[YEAR]NULLPLAN_ROW01
|--Parallelism(Gather Streams)132ParallelismGather StreamsNULLNULL800,028507491185,53845[Testdb].[dbo].[Table1].[YEAR]NULLPLAN_ROW11
|--Hash Match(Partial Aggregate, HASH:([Testdb].[dbo].[Table1].[YEAR]), RESIDUAL:([Testdb].[dbo].[Table1].[YEAR] = [Testdb].[dbo].[Table1].[YEAR]))143Hash MatchPartial AggregateHASH:([Testdb].[dbo].[Table1].[YEAR]), RESIDUAL:([Testdb].[dbo].[Table1].[YEAR] = [Testdb].[dbo].[Table1].[YEAR])NULL8049,63581185,50995[Testdb].[dbo].[Table1].[YEAR]NULLPLAN_ROW11
|--Index Scan(OBJECT:([Testdb].[dbo].[Table1].[IX_Table1_Hits]))154Index ScanIndex ScanOBJECT:([Testdb].[dbo].[Table1].[IX_Table1_Hits])[Testdb].[dbo].[Table1].[YEAR]1,449936E+0727,899427,9747291135,87415[Testdb].[dbo].[Table1].[YEAR]NULLPLAN_ROW11
Thank You!!
Is Index Created On Primary Or Secondary Key?
Apr 15, 2015Is index created on only primary key or it can be created on secondary key ?
View 2 Replies View RelatedClustered Index On Composite Primary Key
Jul 23, 2005Is that possible on SQL Server 2000 and onwards?
View 1 Replies View RelatedCreating A Primary Key As A Non Clustered Index
Jul 18, 2007Hi,
I have created a very simple table. Here is the script:
if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[IndexTable]') and OBJECTPROPERTY(id, N'IsUserTable') = 1)
drop table [dbo].[IndexTable]
GO
CREATE TABLE [dbo].[IndexTable] (
[Id] [int] NOT NULL ,
[Code] [nvarchar] (50) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL
) ON [PRIMARY]
GO
CREATE CLUSTERED INDEX [CusteredOnCode] ON [dbo].[IndexTable]([Id]) ON [PRIMARY]
GO
ALTER TABLE [dbo].[IndexTable] ADD
CONSTRAINT [PrimaryKeyOnId] PRIMARY KEY NONCLUSTERED
(
[Id]
) ON [PRIMARY]
GO
The records that i added are:
Id Code
1 a
2 b
3 aa
4 bb
Now when i query like
Select * from IndexTable
I expect the results as:
Id Code
1 a
3 aa
2 b
4 bb
as i have the clustered index on column Code.
But i m getting the results as:
Id Code
1 a
2 b
3 aa
4 bb
as per the primary key order that is a non clustered index.
Can anyone explain why it is happening?
Thanks
Nitin
Question On Primary Key, Unique Index
Oct 8, 2007
Question: I have a test table like this
CREATE TABLE [dbo].[Test](
[name] [varchar](50) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL,
[addr] [varchar](50) COLLATE SQL_Latin1_General_CP1_CI_AS NULL,
CONSTRAINT [PK_Test] PRIMARY KEY CLUSTERED
(
[name] ASC
)WITH (PAD_INDEX = OFF, IGNORE_DUP_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY]
But when I tried to input my data like
'abc', '123 abc'
'abc ','123 abc'
SQL server won't recognize 'abc' and 'abc ' is a different value if the last character is a space. Is there a way to make it as a different value? I tried to drop the primary and input the data. When I ran a group by the name column, 'abc' show 2 instead of 1. Seems SQL server is trying to ignore the space at the end too.
I also noticed unique index have the same problem too. Please help.