Posts filed under 'MSDN'

MSDN Lightweight View

Following on from my last post on the MDSN Low Bandwidth View, Scott Hanselman recently tweeted about the beta version of MDSN Lightweight View.

In a similar way to adding (loband) before the .aspx part of the url, putting (lightweight) before the .aspx part of the url will use the new lightweight view of MSDN, meaning a much neater and streamlined version.

In addition, Scott has previously posted about the other modes of MSDN:

Mode Description Example
- The normal MSDN view. Example
(loband) A minimal view, focussed on speed. Example
(lightweight) A faster lightweight view, including quick links to switch between languages and .Net framework versions. Example
(pda) Aimed at PDAs and phones. Turns off the tree and allows a 100% width. Example
(robot) Optimised for search engines. Example
(printer) A printable version. Example
(ide) Used when viewing inside the IDE. Adds send and give feedback links. Example



Note that the dev10ide view Scott mentions seems to have been removed, and that the lightweight view is currently in beta, so may be liable to change.

Add comment Permalink July 7th, 2009 Adrian Banks
Subscribe to this feed Bookmark this post on del.icio.us Digg this post on digg.com Share this post

MSDN Low Bandwidth View

Several months ago, I read a tip about passing an extra parameter on the url to MSDN documentation to put it into “low bandwidth” mode. I remember doing it at the time, but almost immediately forgot the url switch. That was until last week when I read Eric Nelson’s post on how to do it.

The trick is to put (loband) before the .aspx part of the url. For example, the low bandwidth version of

http://msdn.microsoft.com/en-us/library/system.object.aspx

becomes

http://msdn.microsoft.com/en-us/library/system.object(loband).aspx

Once you have accessed it, you can persist it by clicking on the “Persist low bandwidth view” link.

Since Eric wrote his post, it seems that a “Switch on low bandwidth view” link has been added into the normal MSDN pages to enable it to be switched on without hacking around with the url.

Jon Galloway has a post that summarises the benefits of the low bandwidth view. For me, the biggest benefit is the speed of loading, since the page doesn’t run lots of JavaScript to sync the contents tree to the currently displayed article.

1 comment Permalink April 8th, 2009 Adrian Banks
Subscribe to this feed Bookmark this post on del.icio.us Digg this post on digg.com Share this post

SQL Server 2005 SP3 Released

Service pack 3 for SQL Server 2005 was released last week. In it, they have fixed a curious bug that I reported back in January.

The bug occurs when trying to delete rows from a table that have a NULL value for an image column. This works fine normally, but if there is a foreign key referencing the table (to any of its columns), any rows that have had their image column updated to be NULL fail to be deleted. This SQL demonstrates the problem:

-- create two linked tables
CREATE TABLE [dbo].[TableA]
(
    [Identity] [int] NOT NULL IDENTITY(1, 1) PRIMARY KEY,
    [TableB_Identity] [int] NULL
)

CREATE TABLE [dbo].[TableB]
(
    [Identity] [int] NOT NULL IDENTITY(1, 1) PRIMARY KEY,
    [DATA] image NULL
)

ALTER TABLE [TableA] ADD CONSTRAINT [FK_TableA_TableB]
    FOREIGN KEY ([TableB_Identity]) REFERENCES [TableB] ([Identity])

-- insert some data
INSERT INTO [TableB] ([DATA]) VALUES (NULL)
INSERT INTO [TableB] ([DATA]) VALUES (NULL)
INSERT INTO [TableB] ([DATA]) VALUES (NULL)

-- this delete works successfully
DELETE FROM [TableB] WHERE [DATA] IS NULL
SELECT COUNT(*) AS Remaining_Count_Should_Be_0 FROM [TableB]

-- insert some data
INSERT INTO [TableB] ([DATA]) VALUES (NULL)
INSERT INTO [TableB] ([DATA]) VALUES (NULL)
INSERT INTO [TableB] ([DATA]) VALUES (NULL)

-- update the data to be have a NULL value
UPDATE [TableB] SET [DATA] = NULL WHERE [DATA] IS NULL

-- this delete doesn't work
DELETE FROM [TableB] WHERE [DATA] IS NULL
SELECT COUNT(*) AS Remaining_Count_Should_Be_0 FROM [TableB]

-- this delete doesn't work
DELETE FROM [TableB] WHERE ISNULL([DATA], NULL) IS NULL
SELECT COUNT(*) AS Remaining_Count_Should_Be_0 FROM [TableB]

-- this delete does work successfully
DELETE FROM [TableB] WHERE EXISTS
    (
        SELECT * FROM [TableB] AS TB
        WHERE [DATA] IS NULL
        AND TB.[Identity] = [TableB].[Identity]
    )
SELECT COUNT(*) AS Remaining_Count_Should_Be_0 FROM [TableB]

Not all of the delete queries work correctly. The output of the script is four result sets with the count of how many rows are in the table at each point. All of them should be 0 (as is the case on SQL Server 2000), but in SQL SERVER 2005 without SP3 they are actually 0, 3, 3 and 0.

The simple delete query:

DELETE FROM [TableB] WHERE [DATA] IS NULL

does not delete any rows after the values for the Data column have been updated to NULL, even though a similar select query:

SELECT * FROM [TableB] WHERE [DATA] IS NULL

will return rows.

Notably, if either the foreign key is removed, or the:

UPDATE [TableB] SET [DATA] = NULL WHERE [DATA] IS NULL

query is not performed, the script behaves as expected. Additionally, using text or ntext instead of image does not work as well, but using the new varchar(max), nvarchar(max) or varbinary(max) data types does work.

Apparrently, the distinction between NULL values stored as a result of an insert or an update has precendece in the WRITETEXT command:

If the table does not have in row text, SQL Server saves space by not initializing text columns when explicit or implicit null values are added in text columns with INSERT, and no text pointer can be obtained for such nulls. To initialize text columns to NULL, use the UPDATE statement. If the table has in row text, you do not have to initialize the text column for nulls and you can always get a text pointer.

This points to the "text in row" option having a bearing on this behaviour. Indeed, altering this option after creating the tables:

sp_tableoption N'TableB', 'text in row', 'ON'

results in the script working as expected. Useful as a potential workaround.

The bug is present in all versions of SQL Server 2005, but not in SQL Server 2000 or 2008.

A full list of what's changed in SP3 can be found here, with a full list of the bugs fixed here.

Add comment Permalink December 23rd, 2008 Adrian Banks
Subscribe to this feed Bookmark this post on del.icio.us Digg this post on digg.com Share this post

Useful Diagnostic Tools

I recently visited a customer site to diagnose some problems with an application deployed on a server. Because I was effectively "visiting blind" in not knowing what was wrong or even if I would have internet access, I had to pre-empt any potential problems and take whatever tools I would need to diagnose them with me.

The following is a list of the tools I took:

  • Active Ports
    This is an equivalent to running netstat -nabv 5 from the command line, but wraps a nice GUI around it with the ability to look up the host names for connected IP addresses.
  • BareTail
    This is a simple log file viewer that can "tail" a running log and apply highlighting based on custom searches.
  • CorFlags
    This is a tool that comes as part of the Visual Studio SDK and enables a .Net application to be forced to run as 32-bit on 64-bit hardware. Existing applications can be tweaked without re-compilation.
  • Culture Launcher
    This is one of my own tools that can launch an .Net application using a different culture/language. The culture and UI culture can be set independently of each other.
  • Error Lookup
    This is a small tool that comes with Visual Studio (when you install the C++ components). It enables Win32 error codes to be translated into "meaningful" English error messages.
  • Managed Stack Explorer
    This is a tool that can preiodically capture stack traces from running .Net applications. It also shows a variety of information about the managed processes and threads running on a machine.
  • Red Gate Diagnostics Tool
    This is a tool from Red Gate that collects lots of system information from a computer. It is very useful because of the amount of data that it collects all in one place.
  • Snippet Compiler
    This is like a cut-down version of Visual Studio. It has an IDE-like editor (with only basic intellisense) and can compile and run .Net applications. The biggest plus is that it requires no installation.
  • SpaceMonger
    This is a tool that gives a visual representation of disk usage for a whole drive. This version is an older version of the tool, but is the last version that is free.
  • SysInternals
    This is the famous SysInternals Suite of tools, now owned by Microsoft, but still occasionally updated with new features and bug fixes. This contains lots of file, disk, network, process, registry and system utilities.

This toolset (along with a few custom-written SQL scripts) provided me with everything I needed to collect all the information I needed to get to the bottom of the problems.

2 comments Permalink July 8th, 2008 Adrian Banks
Subscribe to this feed Bookmark this post on del.icio.us Digg this post on digg.com Share this post

Fixing Database Logins After A Restore

For several years now I've been moving development databases between SQL Servers using backup and restore. When you restore the database on the target server, the logins for the database are invariably broken with the database user having an empty login name, meaning that they cannot log in to the database. My usual fix is to delete the database user and re-add it. Paul Hayman however pointed out a useful stored procedure to fix broken logins:

sp_change_users_login 'Auto_Fix', 'username'

where username is the name of the account to fix.

The Auto_Fix option will attempt to match the broken login with an existing user with the same name.

More information on this can be found in the MSDN documentation. Specific things to note are that it only works with SQL Server and not Windows logins, and that you must be a member of the sysadmin fixed server role for it to work.

Add comment Permalink July 17th, 2007 Adrian Banks
Subscribe to this feed Bookmark this post on del.icio.us Digg this post on digg.com Share this post

Previous Posts


Calendar

March 2017
M T W T F S S
« Oct    
 12345
6789101112
13141516171819
20212223242526
2728293031  

Posts by Month

Posts by Category

RSS Feeds Feeds

Visitors

Visitor Map