create table article
(
ArticleID int constraint cnst-name Primary key,
Description datatype
)
I am creating this table in SQL Server 2014. I am trying to create a table where I can store articles with huge data (it can be 1000-2000 words article description). I don't know which data type to choose for description column.
I chose varchar(max) but there is a limitation that each row has to be <= 900 bytes. Please guide me if my table structure is right.
Thanking in anticipation.
Use VARCHAR(max).
2000 words in a .txt file is around 13kb.
I would not call that 'huge'.
I would use nvarchar(max). Unlike varchar is supports unicode. The limit 2GB should be enough.
The limit of row size is 8060B, so You can not store more than about 4000 unicode characters in the row. But the restriction does not apply here, because nvarchar(max) is not stored in the row. The row contains pointer only. This one indirection is the price for the "unlimited" size.
Related
I can't set varbinary with maximum size in MySql 8.0
Show this error message :
Could not set value
Please write correct syntax.
Thanks.
In MySQL, one can't use 'max' as length like SQL Server. If you want a column with max size binary data, then LONGBLOB is a better option.
https://dev.mysql.com/doc/refman/5.5/en/blob.html
setting VARBINARY(65535) will throw an error in mysql if you have other columns
Query error:
#1118 - Row size too large. The maximum row size for the used table type, not counting BLOBs, is 65535. This includes storage overhead, check the manual. You have to change some columns to TEXT or BLOBs
in my case setting it to varbinary(65450) was successful because I have 11 more columns to consider.
I have a column in table with text datatype and trying to save some string value to this column from C# code. Issue comes when I use some very large string.
I am not able to save more than 43679 character into text field. I know text size can be 2^31.
I also tried saving same value from SSMS and noticed same scenario.
There is nothing special about code, but still SQL query is given below...
update TableName
set ColumnName = 'some text more than 43679 char'
where id=<some int id>
just to mention... column is declare in table as
[columnname] [text] NULL
Can anyone tell me what could be wrong.
You can try to use varchar(max) to store huge amount of data. See MSDN
We recommend that you store large data by using the varchar(max),
nvarchar(max), or varbinary(max) data types. To control in-row and
out-of-row behavior of these data types, use the large value types out
of row option.
You can also check the same issue here: SSMS - Can not paste more than 43679 characters from a column in Grid Mode
My company use sql server 2000 to store data . There is a table with a column named 'Vattu' .
The problem is that : this column declare as varchar data type , however it's save both unicode and anscii value !
So every time I show this column data on web , it show unreadable characters.
Is there any way to convert data to unicode value using c# ?
A quick google search would have given you the answer. Anyway you use System.Text.Encoding to encode the ascii to unicode. check the sample code at Encoding.Convert Method
Also converting the column datatype to NVarchar will be better in long run. Doing so you will save CPU processing that you will be using due to conversion at c# level.
You need to change the data type of the column to nvarchar in order to store Unicode data.
The Unicode data you've already tried to store in the column is gone - you can't magically get it back, unless your application logged the data or you were running traces of all commands and still have access to those.
I will be having a table in SQL Server 2008 that will hold millions of rows and the initial design will be:
Code nvarchar(50) PK
Available bit
validUntil DateTime
ImportID int
The users can import 100,000 odd codes at a time which I will be using sqlbulkcopy to insert the data. They can also request batches of codes of up to 10,000 at a time for a specific ImportID and as long as the request date is less than the ValidUntil date and the code is available.
My question is, will it be better to hold all these codes in the one table and use indexes or to split the one table into two - AvailableCodes and UsedCodes - so whenever codes are requested, they are moved from the AvailableCodes table into the UsedCodes table instead of having the Available flag? That way the AvailableCodes table won't get as massive as a single table as over time there will be more used codes than available codes and I will not be that bothered about them accept for auditing purposes.
Also, if the tables are split will I still be able to use the sqlbulkcopy as the codes will still need to be unique across both tables?
I would create it in one table and create well defined indexes.
Consider a filter index for the flag column. This is done with a where clause in t-sql and the filter page in ssms.
http://msdn.microsoft.com/en-us/library/cc280372.aspx
The application I have completed has gone live and we are facing some very specific problems as far as response time is concerned in specific tables.
In short, response time in some of the tables that have 5k rows is very low. And these tables will grow in size.
Some of these tables (e.g. Order Header table) have a uniqueidentifier as the P.K. We figure that this may be the reason for the low response time.
On studying the situation we have decided the following options
Convert the index of the primary key in the table OrderHeader to a non-clustered one.
Use newsequentialid() as the default value for the PK instead of newid()
Convert the PK to a bigint
We feel that option number 2 is ideal since option number 3 will require big ticket changes.
But to implement that we need to move some of our processing in the insert stored procedures to triggers. This is because we need to trap the PK from the OrderHeader table and there is no way we can use
Select #OrderID = newsequentialid() within the insert stored procedure.
Whereas if we move the processing to a trigger we can use
select OrderID from inserted
Now for the questions?
Will converting the PK from newid() to newsequentialid() result in performance gain?
Will converting the index of the PK to a non-clustered one and retaining both uniqueidentifier as the data type for PK and newid() for generating the PK solve our problems?
If you faced a similar sort of situation please do let provide helpful advice
Thanks a tons in advance people
Romi
Convert the index of the primary key in the table OrderHeader to a non-clustered one.
Seems like a good option to do regardless of what you do. If your table is clustered using your pkey and the latter is a UUID, it means you're constantly writing somewhere in the middle of the table instead of appending new rows to the end of it. That alone will result in a performance hit.
Prefer to cluster your table using an index that's actually useful for sorting; ideally something on a date field, less ideally (but still very useful) a title/name, etc.
Move the clustered index off the GUID column and onto some other combination of columns (your most often run range search, for instance)
Please post your table structure and index definitions, and problem query(s)
Before you make any changes: you need to measure and determine where your actual bottleneck is.
One of the common reasons for a GUID Primary Key, is generating these ID's in a client layer, but you do not mention this.
Also, are your statistics up to date? Do you rebuild indexes regularly?