when to use table variable and temp table. i told the interviewer that when rows is less like hundreds or thousand then use table variable else use temp table.After that he asked that what do u mean by less data or thousand rows may be there are multiple columns involved with that less rows and make a huge data set.
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Hello,
the application will add items into a "bag". That is, the items in one table will refer a record in another table. This will be done in timely manner -- with second or minute delays between adding a new item. There will be up to thouthand of items per bag. The option is to wait until a full bag accumulates and set up all the references at once by using
UPDATE items SET container_ref = bag WHERE id IN [...]
The disadvantage of such all-at-once I see is inability to encapsulate the functionality into a SP -- the problem is to pass a set of IDs. The advantage should be efficiency in terms of total SQL Server load. How mush would it be?
Hi Experts
We are debating what is best:
1. To combine all the company's data in one large database, and use schemas and file groups to create logical and physical distribution on drives and namespaces
or
2. Distribute the data into smaller databases with related data - eg. products and product description in one db, Customers in another and orders and orderlines in a third db.
Just what are the pros and cons?
regards
Jens Chr
System.OverflowException: Value was either too large or too small for an
Int32. Why does this error originate in the following line?"SqlCommand cmd = new SqlCommand("SELECT Count(*) FROM Contacts", conn)........ ..........DataSetContacts.ContactsRow row = ds.Contacts.NewContactsRow();..................row["ContactNumber"] = Convert.ToInt32(txtContactNo.Text);" ContactNumber field is SqlDbType.Int.
HiThis is a question of "what does it cost me".Lets say I have an integer value which would fit into a smallint fieldbut the field is actually defined as int or even larger as bigint.What would that "cost" me ? How would definitions larger than I need forthe values in the field affect me ?Its obvious that the volume of the database would grow but with the sizeof resources etc that we have nowadays disc space isn't a problem likeit used to be and i/o is much faster and many people would tell me "whocares" , or IS it a problem ?How does it affect performance of data retrieves ? Searches ? Updatesand inserts ? How would it affect all db access if tables are pointingat each other with foreign keys ?Thanks !David Greenberg
View 3 Replies View RelatedHI There,
Generally speaking, is it better to use a large or small stripe size for a Raid 5 array (4 drives) ? I would appreciate any specifics also.
Thanks in advance.
Charlie
Hi,
Please could you tell me how big sql tables are when people refer to them as small, medium and large? Preferably in terms of disk space or rows (each row in my table will contain a standard length job advert and 20 additional columns with an average of 8 characters)
Thanks for your help! :-)
Stu
Hi ,
Is there any method by which I can divide the large flat file into certain number of small files keeping the header in each of the sub files?
Regards,
Prash
I have a small number of rows in a dataset, Table 1. There is a CLOB on a large dataset, Table 2. They join on a PK. I would like to retrieve this CLOB and add it to the data flow for Table1. In short I want to emulate the following:
Table 1: Small table without CLOB, 10 rows.
Table 2: Large table with CLOB, 10,000,000 rows
select CLOB
from table2
where pk = (select pk from table1)
I want this to return the CLOBs for the small number of rows in Table 1. The PK is indexed obviously so it should be a fast look up.
Table 1 and Table 2 live on different Oracle databases. How do I perform this operation efficiently in SSIS? It seems the Lookup and Merge Join wont do this.
Which is more efficient? One large view that joins >=10 tables, or a few smaller views that join only the tables needed for individual pages?
View 1 Replies View RelatedI want to store a small cirle in a text field. Can anyone tell me how I can enter it in ascii code.
Thanks
I have a project need to store the information of reservation. For example, somebody wants to reserve a laptop. She will sign in the date from calender to use. I would like to let the administrator to access the database and update the database in the intranet. Also the user who want to reserve a resource can access the intranet to fill a form, after approving it, she can borrow the resource. Of course, this is small database. And we also have a report on this.Do you have any idea how to do it? I appreciate.
View 1 Replies View RelatedHy everyone,
I have a problem at pulling data on PDA using Sql Mobile 5 from Sql Server 2000.
It work s for most tables, except for two . Every table of those two has about 1000 records and every record about 150 bytes, so all data is about 150 kbytes.
When I connect to the Sql Server 2000 through LAN, no problem. But when I connect through GPRS - VPN, the error occurs. But, the PDA- phone connection is via Bluetooth and at ping no TimeOut appears, the replies are about 600-700 ms. When connecting with a desktop computer through GPRS no such problem occurs.
So , I don't know what could be the cause: the connection or the Sql Mobile which doesn't retry enough in case of error to transfer all data .
A specialist from the GPRS provider told me to use 3G phone , but , because the GPRS phones have already been bought, this would be a too big investment. So, I don't think this is a good idea in this moment .
I found similar problem on the net and a solution was to use Pooling = False. But , in Sql Mobile there is no pulling parameter available when making the connection string .
Any help is very precious to me ,
Mihai .
All source and target date fields are defined as data type "smalldatetime". The "select" executes without error though when used with "insert into" it fails with the error:
Msg 295, Level 16, State 3, Line 25: Conversion failed when converting character string to small date-time data type..I am converting from a character string to smalldatetime since the source and target date columns are "smalldatetime". All other columns for the source and target are nvarchar(255). I assume there is an implicit conversion that I don't understand. In a test, I validated that all dates selected evaluate ISDATE() to 1.
USE [SCIR_DataMart_FromProd_06_20_2014]
GO
IF OBJECT_ID ('[SCIR_DataMart_FromProd_06_20_2014].[dbo].[IdentifierLookup]', 'U') IS NOT NULL
DROP TABLE [SCIR_DataMart_FromProd_06_20_2014].[dbo].[IdentifierLookup]
[code]....
I am studying indexes and keys. I have a table that has a fixed width of data to be loaded in the first column which is parsed in a view based on data types within the fixed width specifications.
Example column A:
(name phone house cost of house,zipcodecountystatecountry)
-a view will later split this large varchar string based
column b: is the source filename of the data load (varchar 256)
....
a. would there be a benefit of adding a clustered or nonclustered index (if so which/point in direction on why)
b. is there benefit of making one of these two columns a primary key (millions of records) or for adding a 3rd new column as a pk?
c. view: this parses the data in column a so it ends up looking more like "name phone house cost of house zipcode county state country" each having their own column.
-any pros/cons of adding indexes (if so which) to the view instead of the tables or both for once the data is parsed?
hello guyshere is my problem:i am developing a asp.net web app in .net 2.0. i have some sensitive data in my database. which is encrypted using DES ( with some key which is only known by the top level authorities ). now there is an option of changing the secret key. on changing the key the sensitive data has to decrypted using the old key and then again encrypted using the new key. Now if the no of records increases i am afraid that it might take a longer time and the application might look as it got hanged. guys i have no clue on how to do this. if you guys have any idea on how to implement this please let me know. any help would be appreciatedVignesh
View 7 Replies View RelatedHi,
I'm currently trying to retrieve results from a large dataset, there are over 45000 records and I need to use them all to peform counts etc. I have set up views, but my page is still being returned slowly, is there anything I can do to speed this up?
Thanks
Gemma
I was wondering if anyone can help me.
I am trying to import data into SQL Server 7. The table will be 700-800 columns, and the data will be about 150,000 records at a time.
The data source is flat file.
First I create the table using a database schema, and secondly I would like to populate the table.
The problem is that most of the data is numeric, and to be used for statistical analysis.
So far I have tried Bulk Insert, bcp, and dts.
DTS is the only method that has worked in any way, shape or form, but that requires importing each column as a Varchar. Importing to my pre-created table doesn't work, because it is interpreting some of the source columns as character data and refusing to insert them into an int field.
Bulk Insert and bcp both give error messages, and I am wondering if that is because of the size of the insert statement that is required to handle so many fields.
For the moment I am just trying to import the data in any way, but eventually, it will have to be run as an automated process, with the table structure probably needing to be altered as well.
Any help/suggestions would be very greatfully received.
I have a web site that allows user to enter large strings into a database (comments, etc). What is the best way to do that? Right now I have them limited to 25 characters and the data type is varchar. Is there a better way?
Thanks!
I want to build a system that will have about 1 million rows in atable in sql server database.I am using this for a web application andaccessing it via JDBC type 4 driver.But display 20 records at a timeonly using pagination(as in google).What will be the best way to goabout this.
View 1 Replies View RelatedI have a database that is 70GB big. One of the tables has over 350million rows of data. I need to delete about 1/3 of the data in thatone table.I was going to use a simple delete command to delete the unnessacaydata.Something likeDelete from tablename where columname > '100'However, it takes SOOO LONG to run, over 8 hours, if not longer....What is the best way to delete this data???One idea was to create a Temp Table, then move the needed data to thetemp table, then Truncate the Table, and move that data back.I'm not very good with SQL Query Language, so can somone give me anexample on how to do this?? Or if you have a differant idea that wouldbe faster please let me know.thanks,Sam
View 2 Replies View RelatedHiI have a SQL2000 server with 128m rows of data. I want to delete about65m of that. So far I have bcp'ed the relevent data out and put theminto another SQL database.We have a small amount of space for our transaction log so I cannotdelete all 65m rows in one go. So far I have been doing them is 0.5mchuncks, but it is extremly slow.Would a faster way be to bcp the data I wan to keep and truncate thetable and bulk import them in again ?What hapnes to log size in when builk import is happening and is thereanother way of doing this ?Thanks for any help
View 2 Replies View RelatedI want to store some binary things(pic and so on), so I create a table which contain a a "varbinary" data-type column.
but 1. I used OPENROWSET to insert the large file in this table. 2. I used master..xp_cmdshell to retrieve data out as a file. One strange thing happened: the size of the input and output is really different(output is 1k bigger than the input file).
and it seems that the file is broken with different file format......
I really don't know why....
Any help would be appriciated.....
kavin
Hi All,
How do I input a large text page (notepad) into a SQL column. Or assign a pointer to the data. I've tried to use BOL (writetext) and to no avail, I guess I'm missing something. I'm just using EM and Query analyzer. I thought this should be easy. Image data should work the same way.
TIA,
Dave
Hello:
The purchased-application mssql 6.5, sp 4 that I am working on has one large table has 13m illion. It the largest table considering thenextlatgest table is only1.75 million rows.
Thew vnedor has made a change to this largest table in recommending changing a data type -- char to varchar. To make this change easier to do,
I want to "archive" older data not necessary for the current year or current processing to another table.
What is the best way to do this archiving?
Any information you can provide will be greatly appreciated. Thanks.
David Spaisman
Hi all,
I have a table which basically stores multiple users' responses to a questionnaire. I want to calculate certain statistics on this data (for example: how many users selected a specific answer to a question). If there are many questions and possible answers, then this can get really inefficient. I was wondering what would be the best way to go about doing this.
Currently, I was thinking of using what I believe are called crosstabs:
Code:
SELECT (SELECT COUNT(*) FROM tableName WHERE Q1answer='value1'), (SELECT COUNT(*) FROM tableName WHERE Q1answer='value2'), (SELECT COUNT(*) FROM tableName WHERE Q2answer='value1'), etc...
Is this the best way to go about this or is this really inefficient?
I have run the select query which returned one row. There is one column in it which has got large amount of data. I want to copy the complete content of that column(varchar(max)), but I am unable to do it. It's not the xml data. I don't want to do any conversions.
View 1 Replies View Relatedhello
i have just created a test database and now need to insert a large number of records into one of the tables, we were thinking of about 1 million records, has anyone got an sql script that i could use to create these records
cheers
john
Hi i wanna delete all the records from an large database 200 -300 tables, because i want make some changes an start from scratch,but keep the structures of the database key , index etc, i tried to generate script but when i run to many errors , plz help 10x
View 11 Replies View RelatedHi,
I was wondering if any one could help me, I need to store large amounts of data in my database, at present I have it set to nvchar (8000), I've looked around and noticed you can use text which stores up to 2 million, but is slow in displaying the information.
Any ideas or points in the right directions would be great.
Thanks
Does anyone have ideas on the best way to move large amounts of databetween tables? I am doing several simple insert/select statementsfrom a staging table to several holding tables, but because of thevolume it is taking an extraordinary amount of time. I consideredusing cursors but have read that may not be the best thing for thissituation. Any thoughts?--Posted using the http://www.dbforumz.com interface, at author's requestArticles individually checked for conformance to usenet standardsTopic URL: http://www.dbforumz.com/General-Dis...pict254055.htmlVisit Topic URL to contact author (reg. req'd). Report abuse: http://www.dbforumz.com/eform.php?p=877392
View 4 Replies View RelatedThis is a general question on the best way to import a large amount of datato a MS-SQL DB.I can have the data in just about any format I need to, I just don't knowhow to import the data. I some experience with SQL but not much.There is about 1500 to 2000 lines of data. I am looking for the best way toget this amount of data in on a monthly basis.Any help is greatly thanked!!Mike Charney
View 5 Replies View RelatedBrief background:We are using SQL Server 2000, and one of the tables stores usersessions details (each time our users logs into our system we insert anew record in the session table, and each time user logs out from oursystem we insert another record in the same table).SESSION_ID is the primary key and it is clustered index.The system produces 5 million session records/day.The problem:Each day we transfer the session data (delta only) to other machine andwe want to delete bulk of ~5 million sessions. This should happendwithout any interfering of our customers activity ( in the same time,we should not block the table - new sessions should be created).What is the best way to perform such task ?
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