Is there a recommended practice for mirroring in regards to distance? Is it best practice to mirror with both nodes at the same physical location and use another method for failing over to a remote location or can one just put the other node in the mirror a few thousand miles away? I'm suspecting not.
Any comments??
Hi
How do I get a nearest distance of a point? For example, I have two tables A and B and I want to find the nearest distance between the records of the two tables. In addition, one of the tables should also give me the distance. The data I have geo spatial data. Can this be done in SQL
Help will be appreciated
Hi,
please, it is possible to know the edit distance used in the fuzzy lookup/grouping.
On this forum I read fuzzy lookup use 4-gram with fix size.
Does exist any document explaining how fuzzy lookup calculate the similarity? In other word, what kind of edit distance, algorithm is used by fuzzy lookup/grouping?
I hope I was enough clear with my poor english.
Thanks All
I'm trying to run a dyncamic query that returns all records within a specific distance of a certain point. The longitude and latitude of each record is stored in the database. The query is constructed from two dynamic variables $StartLatitude and $StartLongitude with represent the starting point.
SELECT UserID, ACOS(SIN($StartLatitude * PI() / 180) * SIN(Latitude * PI() / 180) + COS($StartLatitude * PI() / 180) * COS(Latitude * PI() / 180) * COS(($StartLongitude - Longitude) * PI() / 180)) * 180 / PI() * 60 * 1.1515 AS Distance
FROM HPN_Painters
HAVING (Distance <= 150)
It runs fine until I add the 'HAVING (Distance <= 150)' clause, in which I recieve the error: Invalid column name 'Distance' It seems that Distance cannot be referenced in the HAVING clause.
I'm looking to find out how I'd go about setting up a database where avisitor to my site could punch in their postal code, and find out how farthey are from another postal code. For example, AutoTrader has this featureI believe to tell you how far the vehicle is from you. Dating sites havethem so you can do proximity searches.Anyone have any ideas where I could start? I'm thinking the post office,but if anyone else has suggestions, I'm open to hear them.Thanks!
View 4 Replies View RelatedVarious posts have noted that mirroring over distance is not advisable or that either async connections should be used.
Are there any limits/recommendations i.e. if two datacenters are a couple of files part with 10GBs fibre links and <50ms response times would this be acceptable for high-availability mirroring?
I am new to data mining so please excuse my ignorance. Lets assume
- i have created a cluser model
- identified 3 clusters ( a, b, c)
- each record consists of 15 columns
- collecting new records( 15 variables) real time
what i would like to do is plot these new records programmatically as i collect them realtime. I assume this new record will belong to one of these three clusters. I believe we can find the cluster this new record belongs to by ' SELECT Cluster()....' and distance from the center of the cluster by ClusterDistance(). To plot this on a 2-dimentional space i need (x, y).
ClusterDistance() could be Y but what will be X.
thanks.
I have a user defined function, I want to determine the distance between the 2 points. I have it working but i'm having a problem getting to print.
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Code Snippetcreate function dbo.Distance( @lat1 float , @long1 float , @lat2 float , @long2 float)
returns float
as
begin
declare @DegToRad as float
declare @Ans as float
declare @Miles as float
set @DegToRad = 57.29577951
set @Ans = 0
set @Miles = 0
if @lat1 is null or @lat1 = 0 or @long1 is null or @long1 = 0 or @lat2 is
null or @lat2 = 0 or @long2 is null or @long2 = 0
begin
return ( @Miles )
end
set @Ans = SIN(@lat1 / @DegToRad) * SIN(@lat2 / @DegToRad) + COS(@lat1 / @DegToRad ) * COS( @lat2 / @DegToRad ) * COS(ABS(@long2 - @long1 )/@DegToRad)
set @Miles = 3959 * ATAN(SQRT(1 - SQUARE(@Ans)) / @Ans)
set @Miles = CEILING(@Miles)
return ( @Miles )
end
DECLARE @RC float
EXEC Distance '39.943762', '-78.122265', '32.334709', '-96.633546'
PRINT @RC /* in miles */
Server A = primary SQL DBs (mirroring origination)
Server B = failover SQL DBs (mirroring destination)
For database mirroring a witness is required.
Can the witness live in another instance of SQL on server B?
Great Circle distance calculation
Is there any stored procedure or application that implements Great Circle distance calculation
DECLARE @Latitude NUMERIC(9, 6), @Longitude NUMERIC(9, 6)
DECLARE @MyLatitude NUMERIC(9, 6), @MyLongitude NUMERIC(9, 6)
Set @Latitude = 42.329596;
Set @Longitude = -83.709286;
Set @MyLatitude = 42.430883;
Set @MyLongitude = -82.923642;
Question: How do we calculate the distance in miles between the 2 points.
I am trying to write a piece of SQL which gives me a list of enquiries within 10 metre distance of a enquiry.
The idea is to identify possible duplicates.
Table: enquiry
Primary key: enquiry_number
Co-ordinates data fields: enquiry.enquiry_easting and enquiry.enquiry_northing.
I will need to self-search on the same table to find possible enquiries within 10m distance.
See here www.merriampark.com/ld.htm for information about the algorithm. This page has a link (http://www.merriampark.com/ldtsql.htm) to a T-SQL implementation by Joseph Gama: unfortunately, that function doesn't work. There is a debugged version in the also-referenced package of TSQL functions (http://www.planet-source-code.com/vb/scripts/ShowCode.asp?txtCodeId=502&lngWId=5), but this still has the fundamental problem that it only works on pairs of strings up to 49 characters.
CREATE FUNCTION edit_distance(@s1 nvarchar(3999), @s2 nvarchar(3999))
RETURNS int
AS
BEGIN
DECLARE @s1_len int, @s2_len int, @i int, @j int, @s1_char nchar, @c int, @c_temp int,
@cv0 varbinary(8000), @cv1 varbinary(8000)
SELECT @s1_len = LEN(@s1), @s2_len = LEN(@s2), @cv1 = 0x0000, @j = 1, @i = 1, @c = 0
WHILE @j <= @s2_len
SELECT @cv1 = @cv1 + CAST(@j AS binary(2)), @j = @j + 1
WHILE @i <= @s1_len
BEGIN
SELECT @s1_char = SUBSTRING(@s1, @i, 1), @c = @i, @cv0 = CAST(@i AS binary(2)), @j = 1
WHILE @j <= @s2_len
BEGIN
SET @c = @c + 1
SET @c_temp = CAST(SUBSTRING(@cv1, @j+@j-1, 2) AS int) +
CASE WHEN @s1_char = SUBSTRING(@s2, @j, 1) THEN 0 ELSE 1 END
IF @c > @c_temp SET @c = @c_temp
SET @c_temp = CAST(SUBSTRING(@cv1, @j+@j+1, 2) AS int)+1
IF @c > @c_temp SET @c = @c_temp
SELECT @cv0 = @cv0 + CAST(@c AS binary(2)), @j = @j + 1
END
SELECT @cv1 = @cv0, @i = @i + 1
END
RETURN @c
END
I am trying to use the haversine function to find the distance betweentwo points on a sphere, specifically two zip codes in my database. I'mneither horribly familiar with SQL syntax nor math equations :), so Iwas hoping I could get some help. Below is what I'm using and it is,as best as I can figure, the correct formula. It is not however,giving me correct results. Some are close, others don't seem right atall. Any ideas?SET @lat1 = RADIANS(@lat1)SET @log1 = RADIANS(@log1)SET @lat2 = RADIANS(@lat2)SET @log2 = RADIANS(@log2)SET @Dlat = ABS(@lat2 - @lat1)SET @Dlog = ABS(@log2 - @log1)SET @R = 3956 /*Approximate radius of earth in miles*/SET @A = SQUARE(SIN(@Dlat/2)) + COS(@lat1) * COS(@lat2) *SQUARE(SIN(@Dlog/2))SET @C = 2 * ATN2(SQRT(@A), SQRT(1 - @A))/*SET @C = 2 * ASIN(min(SQRT(@A))) Alternative calculation*/SET @distance = @R * @Cthnx,cjrsumner
View 7 Replies View Related
Great Circle distance calculation
Is there any stored procedure or application that implements Great Circle distance calculation
hi everyone:
the report show two tables two matrixs
how can i control the distance between them
I want to set the same distance between the table and matrix
or (table and table )
Could I implement a failover cluster solution on the two DBs which are based in two different cities?
Possible?
I need to be able to take the latitude and logitude of two locations and compare then to determine the number of miles between each point. It doesn't need to account for elevation, but assumes a flat plane with lat and long.
Does anyone have any algorithms in T-SQL to do this?
Given the following example;
declare @CustIfno table (AccountNumber int, StoreID int, Distance decimal(14,10))
insert into @CustIfno values ('1','44','2.145223'),('1','45','4.567834'),
('1','46','8.4325654'),('2','44','7.8754345'),('2','45','1.54654323'),
('2','46','11.5436543'), ('3','44','9.145223'),('3','45','8.567834'),
('3','46','17.4325654'),('4','44','7.8754345'),('4','45','1.54654323'),
('4','46','11.5436543')
How can I show the shortest Distance by AccountID and StoreID. Results would look like this;
AccountNumberStoreID Distance
1 44 2.1452230000
2 45 1.5465432300
3 45 8.5678340000
4 45 1.5465432300
This function computes the great circle distance in Kilometers using the Haversine formula distance calculation.
If you want it in miles, change the average radius of Earth to miles in the function.
create function dbo.F_GREAT_CIRCLE_DISTANCE
(
@Latitude1 float,
@Longitude1 float,
@Latitude2 float,
@Longitude2 float
)
returns float
as
/*
fUNCTION: F_GREAT_CIRCLE_DISTANCE
Computes the Great Circle distance in kilometers
between two points on the Earth using the
Haversine formula distance calculation.
Input Parameters:
@Longitude1 - Longitude in degrees of point 1
@Latitude1 - Latitude in degrees of point 1
@Longitude2 - Longitude in degrees of point 2
@Latitude2 - Latitude in degrees of point 2
*/
begin
declare @radius float
declare @lon1 float
declare @lon2 float
declare @lat1 float
declare @lat2 float
declare @a float
declare @distance float
-- Sets average radius of Earth in Kilometers
set @radius = 6371.0E
-- Convert degrees to radians
set @lon1 = radians( @Longitude1 )
set @lon2 = radians( @Longitude2 )
set @lat1 = radians( @Latitude1 )
set @lat2 = radians( @Latitude2 )
set @a = sqrt(square(sin((@lat2-@lat1)/2.0E)) +
(cos(@lat1) * cos(@lat2) * square(sin((@lon2-@lon1)/2.0E))) )
set @distance =
@radius * ( 2.0E *asin(case when 1.0E < @a then 1.0E else @a end ))
return @distance
end
Edit: corrected spelling
CODO ERGO SUM
Hi All,
Does anyone have a Stored Procedure that works perfectly to retrieve all zipcodes within a specified zipcode and distance radius - a zipcode and radius is passed and the Store Procedure result shows all zipcodes that falls within that range.
Thanks in advance
Ade
I have the two following locations.
They're both towns in Australia , State of Victoria
Fitzroy,-37.798701, 144.978687
Footscray,-37.799736, 144.899734
After running geography::Point(Latitude, Longitude , 4326) on the latitude and longitude provided for each location, my Geography column for each row is populated with the following:
Fitzroy, 0xE6100000010C292499D53BE642C0A7406667511F6240
Footscray, 0xE6100000010C89B7CEBF5DE642C02D23F59ECA1C6240
In my SQL Query, I have the following which works out the distance between both towns. Geo being my Geography column
DECLARE @s geography = 0xE6100000010C292499D53BE642C0A7406667511F6240 -- Fitzroy
DECLARE @t geography = 0xE6100000010C89B7CEBF5DE642C02D23F59ECA1C6240 -- Footscray
SELECT @s.STDistance(@t)
The result I get is
6954.44911927616
I then looked at formatting this as in Australia we go by KM so after some searching I found two solutions one for Miles and the other KM
So I changed Select statement to look like this
select @s.STDistance(@t)/1000 -- format to KM
My result is then
6.95444911927616
When I go to google maps and do a direction request between the locations provided above it says 10.2km (depending on traffic)
Now I'm new to this spatial data within SQL, why would I get a different result from google maps?
Also I would like to round this number so its easier to use within my where statement so I'm using Ceiling as shown here:
SELECT CEILING(@s.STDistance(@t)/1000)
Is ceiling the correct way to go?
Reason I need to round this is because we are allowing the end user to search by radius so if they pass in 50km I will then say
Where CEILING(@s.STDistance(@t)/1000) < 50
I've got a working query which returns all leads within a supplied proximity to a city. I followed a tutorial I googled a couple months ago (can't find it now). It works, but would love others to look the query over (provided DDL and sample data) and tell me if it's as it should be.
Two things I don't like about query:
1. I have to do a UNION to another query that retrieves everything that is in the same city in order to have complete results.
2. very slow to retrieve results (> 1 minute)
Sample DDL: 2 tables
create table dim_lead
(
date_created datetime,
[contact_first_name] varchar(20),
[contact_last_name] varchar(20),
lead_id int,
[Code] .....
Using SQL Server 2008, we would like propose mirroring between two servers of a critical database. Since we initiate, may require to clarify on its purpose and also required changes from application end.Any changes required from OS Level? (I believe both servers IP or Host name should be added in host entries. Mirroring ports should be allowed/open including Principal and mirror server IP Addresses): Windows Team.Any changes required from Application? (Instance name, authentication: user name and its password should be added in web config files): Application Team.Any changes required from Network Team?Also for mirroring both the principal and mirror servers should be with same version, does it only mean SQL Server 2008 versions are enough or does it also mean to say build numbers 10.00.4000 should also be same.URL....
View 5 Replies View RelatedI need to set up asyncronous data replication across two clustered instances of SQL 2012 across 2 Datacenters. Both the datacenters have a common domain however the vlans are different. There are only 3 small databases on the primary instance.
any issue in setting up mirroring in this case as vlans are different.
Operating system is Windows 2012.
Hi All
By mirroring I mean device mirror, since I do not think that there is a database mirror
We only have disk mirror. I also know that SQLServer 7.0 does not provide Mirror, unmirror or remirror. and for this we have to refer to Windows NT disk mirroring.
I need mirroring in both versions SQL Server 6.5 and 7.0
I want to have mirror on another server. I need this for tonight.
Sincerely.
I hereby let u know the steps that i undertook for performing mirroring
1. Created a database in Principal server named Mirror1 and one table named tblMirror1.( no values inside the table)
2. Repeated the same in Mirror in Witness
3. Selected the Principal server's database -->right click-->tasks-->mirror
4. from the left hand panel selected Options -->recovery model-->full
5. selected Mirroring from left hand panel-->configure secuirty-->entered mirror and witness name--Success
6. When I click on start mirroring I have an error stating
" Alter failed for database mirror1"
"Database mirroring cannot be enabled because Mirror1 database may have bulk logged changes that have not been backed up etc...."
7. followed this one
BACKUP database mirror1 TO DISK='C:Program FilesMicrosoft SQL ServerMSSQL.1MSSQLBackupmirror1_FULL.BAK'
got the answer as
Processed 160 pages for database 'mirror1', file 'Mirror1' on file 2.
Processed 1 pages for database 'mirror1', file 'Mirror1_log' on file 2.
BACKUP DATABASE successfully processed 161 pages in 0.318 seconds (4.147 MB/sec).
According to sources
Run a restore of this backup on your mirror.
This can be done through the GUI or using a T-SQL command.
The database restore must use the NO RECOVERY option, so the database stays in a loading state.
Also the database name on the mirror must be the exact same name as the principal
RESTORE TestMirror FROM DISK='C:Backup TestMirror_FULL.BAK' WITH NORECOVERY
Hence did the below
RESTORE database mirror1 FROM DISK='C:Program FilesMicrosoft SQL ServerMSSQL.1MSSQLBackupmirror1_FULL.BAK' WITH NORECOVERY
ERROR
Msg 3201, Level 16, State 2, Line 1
Cannot open backup device 'C:Program FilesMicrosoft SQL ServerMSSQL.1MSSQLBackupmirror1_FULL.BAK'. Operating system error 2(The system cannot find the file specified.).
Msg 3013, Level 16, State 1, Line 1
RESTORE DATABASE is terminating abnormally.
HENCE MODIFIED AS
use master
go
RESTORE database mirror1 FROM DISK='C:Program FilesMicrosoft SQL ServerMSSQL.1MSSQLBackupmirror1_FULL.BAK' WITH NORECOVERY
Msg 3201, Level 16, State 2, Line 1
Cannot open backup device 'C:Program FilesMicrosoft SQL ServerMSSQL.1MSSQLBackupmirror1_FULL.BAK'. Operating system error 2(The system cannot find the file specified.).
Msg 3013, Level 16, State 1, Line 1
RESTORE DATABASE is terminating abnormally.
========
Kindly let me know please where am i going wrong
Regards
cmrhema
hello
if i run dbcc dbreindex on a database thats the principal in a mirrored pair, will the mirrored database indexes also be rebuilt?
i am for the first time creating the database mirroring.I am moving the all the usr databases and everything from test server to a new server called test1.And from that new server i am restoring on the another new server called test2 for database mirroring.But in the test server , the transaction logs are backup for every 15 minutes.So in this case is there a need to move all the logs to test1 and then to test2 for mirroring?? or there is no need to move transaction logs to the new servers at all??
my secnario
------------
server1 server2 server3
-------- ------- --------
test test1 (moving everything from test) test2(mirror for test1 )
all the transaction logs are backup in test for every 15 minutes. so in this case , do i need to move the transcation logs from test to test1 and test2
or there is not need to move at all??
thanks,
Can anyone please tell me what mirroring is??
Thanks in ADvance
RKNAIR
I have sql server 2005 on my vista laptop.
When i set up database mirroring, do i have to set up Principle,
mirror and witness on seperate servers as well as seperate instances.
Or can i install 3 seperate instances on the same laptop im using and still use mirroring? I have tried to start mirroring with all three instances on my laptop but i receive an error.
Regards
Rob
Hi All,
I am trying to set up database mirroring and in the initial phase of database restoring im getting some problem.
the scenario is .
1- I create a TestMirror on server1(which will be principal server) and backup full and transaction logs.
2- create TestMirror in server 2( Which is going to be used as mirror) .
3- restore the full backup of "TestMirror" from Principle Sever with NORECOVERY option.
this step results in a message box showing that the restore was successfull...
but the database explorer( management studio) shows the TestMirror in (restoring ...) state. and no more operations can be performed with this Database. ( because the database is in restoring mode).. please help what this issue is?
Thanks In Advance for any suggestions
-- Krishna
hello
i used following query to create endpoint
CREATE ENDPOINT Endpoint_Mirroring
STATE = STARTED
AS TCP (
LISTENER_PORT=5024
, LISTENER_IP = ALL
)
FOR DATABASE_MIRRORING (
AUTHENTICATION = CERTIFICATE HOST_A_cert
, ENCRYPTION = REQUIRED ALGORITHM RC4
, ROLE = ALL
);
GO
i got the following error msg:
Msg 1498, Level 16, State 2, Line 11
Database mirroring is disabled by default. Database mirroring is currently provided for evaluation purposes only and is not to be used in production environments. To enable database mirroring for evaluation purposes, use trace flag 1400 during startup. For more information about trace flags and startup options, see SQL Server Books Online.
any help plzz
thanks in advance