Database

14-Aug-04 4:43

I have the following query

<br />
SELECT *<br />
FROM (((((SK_SKILLSINAGES AS sia LEFT JOIN SK_SKILLS AS s ON (sia.SkillCode = s.SkillCode) OR (sia.SkillCode = s.ParentSkillCode AND sia.SubSkillCode = s.SkillCode)) INNER JOIN SK_CATEGORY AS c ON sia.CategoryCode = c.CategoryCode) INNER JOIN SK_CATEGORYGROUPS AS cg ON (sia.GroupCode = cg.GroupCode) AND (cg.GroupCode = c.GroupCode)) INNER JOIN AG_AGESINERAS AS ae ON sia.AgeCode = ae.AgeCode) INNER JOIN AG_ERA AS e ON ae.EraCode = e.EraCode) INNER JOIN PR_DEVELOPMENTPOINTS AS pd ON (sia.CategoryCode = pd.CategoryCode) AND (sia.GroupCode = pd.GroupCode)<br />
WHERE ( (sia.SubSkillCode Is Null AND s.ParentSkillCode Is Null) OR (sia.SubSkillCode Is Not Null AND s.ParentSkillCode Is Not Null) AND  sia.CategoryCode = c.CategoryCode AND sia.GroupCode = cg.GroupCode AND sia.AgeCode = ae.AgeCode) AND ae.Description = 'Middle Ages' AND e.Description = 'Rolemaster' AND pd.ProfessionCode = 'ANIMIST'<br />
ORDER BY sia.AgeCode, sia.GroupCode, sia.CategoryCode, sia.SkillCode, sia.SubSkillCode;<br />

I have created an index for each of the fields that are being joined and have created an multiple field index for the sort criteria in SK_SKILLSINAGES however this query still takes a long time to load; around ten seconds. If I remove the ORDER BY sort criteria the query is much much faster. Might I be forgetting something crucial that could help speed up this query. It all seems dependant on the sort.

Thanks!

Colin Angus Mackay15-Aug-04 10:26

15-Aug-04 10:26

I would suggest you run this through the Index Tuning Wizard. Blindly creating indexes isn't really the way to go.

"If a man empties his purse into his head, no man can take it away from him, for an investment in knowledge pays the best interest." -- Joseph E. O'Donnell

Can't manage to P/Invoke that Win32 API in .NET? Why not do interop the wiki way!

brdavid15-Aug-04 11:47

15-Aug-04 11:47

I see that the Index Tuning Wizard is a relic of Microsoft SQL Server database, something I don't have. I am using Microsoft Access and access the jet database through ADO. This could be the reason in itself but with that I don't know. Without having to install an SQL server database package might there be another solution.

I actually managed to get a few indexes in place to get a sorted result so I can remove the ORDER BY stuff, however the query still takes a long time to load. When the statement is calling a simple table to return roughly the same number of records it goes fast, but when I introduce JOIN statements, it gets slow.

Colin Angus Mackay15-Aug-04 12:10

15-Aug-04 12:10

brchris wrote:
I see that the Index Tuning Wizard is a relic of Microsoft SQL Server database

I wouldn't describe it as a "relic"

brdavid15-Aug-04 15:05

15-Aug-04 15:05

True. I meant it in a good way. Wink | ;)

Anonymous23-Aug-04 7:58

Anonymous

23-Aug-04 7:58

Try the following:

SELECT *
FROM SK_SKILLSINAGES AS sia
INNER JOIN AG_AGESINERAS AS ae
	ON sia.AgeCode = ae.AgeCode
	AND ae.Description = 'Middle Ages'
INNER JOIN SK_CATEGORYGROUPS AS cg
	ON sia.GroupCode = cg.GroupCode
INNER JOIN SK_CATEGORY AS c
	ON sia.CategoryCode = c.CategoryCode
INNER JOIN AG_ERA AS e
	ON ae.EraCode = e.EraCode
	AND e.Description = 'Rolemaster'
INNER JOIN PR_DEVELOPMENTPOINTS AS pd
	ON sia.CategoryCode = pd.CategoryCode
	AND sia.GroupCode = pd.GroupCode
	AND pd.ProfessionCode = 'ANIMIST'
LEFT JOIN SK_SKILLS AS s
	ON (sia.SkillCode = s.SkillCode)
	OR (sia.SkillCode = s.ParentSkillCode AND sia.SubSkillCode = s.SkillCode))
WHERE ( (sia.SubSkillCode Is Null AND s.ParentSkillCode Is Null)
	OR (sia.SubSkillCode Is Not Null AND s.ParentSkillCode Is Not Null)
ORDER BY sia.AgeCode, sia.GroupCode, sia.CategoryCode, sia.SkillCode, sia.SubSkillCode;

I have tried to simplify and reorder the SQL. You have a number of joins that restrict the number of records returned (e.g. your "pd.ProfessionCode = 'ANIMIST'" clause). You might want to try moving the more restrictive tables to the top of the "from" clause.

My guess is that the "or" statements involved with the link to SK_SKILLS are the big performance drain (because many databases won't bother to use the indexes) You can test this by removing that part of the statement). A possible way of getting around the "OR" problem is to use a union-join:

SELECT * FROM tables
	WHERE sia.SkillCode = s.SkillCode
UNION ALL
SELECT * FROM tables
	WHERE sia.SkillCode = s.ParentSkillCode
	AND sia.SubSkillCode = s.SkillCode
ORDER BY <columns>

This approach allows the database engine to use separate indexes for the two different links to the skills table.

Hope this helps.
Andy Harman

brdavid28-Aug-04 6:16

Re: C# SQL INSERT String???

28-Aug-04 6:16

You're right about the OR in the SQL. It seems if I remove it, the query goes through faster. Using the UNION query does solve the problem too. Thanks for the reply!

C# SQL INSERT String???

gman4413-Aug-04 12:16

gman44

13-Aug-04 12:16

I have a slight problem inserting the proper result into an MS-SQL table. The result should be <14> however all I get is PRE. BTW, the SQL command not broken appart like you see it on this limited width posting..........

I thought using single quotes desiganted a 'string'? Help........

string pattern1 = @"(<\d{2,3}>)";

Regex r1 = new Regex(pattern1, RegexOptions.Compiled);

Match PRE = r1.Match(stringOfData);
{
try
{
connection1.Open();
SqlDataAdapter1.SelectCommand.CommandText = "INSERT INTO
tblMyUdpServer (col_PRE) VALUES ('PRE')";
SqlDataAdapter1.SelectCommand.ExecuteNonQuery();
connection1.Close();
}
catch(SqlException error)
{
MessageBox.Show(error.Message.ToString());
}
listBox1.Items.Add(PRE.ToString());
}
}

Colin Angus Mackay13-Aug-04 12:47

Re: C# SQL INSERT String???

13-Aug-04 12:47

Ummmm... Are you trying to say that the VALUES('PRE') in your CommandText is supposed to be the result of Match PRE = r1.Match(stringOfData) ???

gman4415-Aug-04 4:03

gman44

15-Aug-04 4:03

Yes, this particular Regex matches numbers between < >. For instance <14>, however only PRE is written to the database........

Re: C# SQL INSERT String???

S Sansanwal15-Aug-04 17:07

S Sansanwal

15-Aug-04 17:07

You are inserting hardCoded "PRE" value rather than variable PRE

Change your sql to

SqlDataAdapter1.SelectCommand.CommandText = "INSERT INTO
tblMyUdpServer (col_PRE) VALUES (" + PRE.Value + ")";

Sanjay Sansanwal
www.sansanwal.com

SELECT in UPDATE statement

blopf13-Aug-04 9:28

blopf

13-Aug-04 9:28

Hello All,
I have a problem that I cannot seem to solve. My guess is that I am thinking wrong. The problem is probably really simple but I cannot seem to solve it. I have two tables, one called test_user and one called test_answer. (Below all types in the tables are integers)

test_user looks like this:
user_id,time_answered,+some other statistics
1 0
2 0
3 0

test_answer looks like this:
test_id,user_id,answered
0 1 1
0 2 1
0 3 0
1 1 1
1 2 1
1 3 0
3 1 1
3 2 0
3 3 0

Basicly test_answered contains a 1 in the answered if the user has answered a question on test test_id.

What I want to do is sum up all the answers and update the test_user table. If I do this SQL-query then I get the table I want to update test_user with.

select user_id,sum(answered) as sum from test_answer where answered = 1 group by user_id

(The output will be:
user_id,sum
1 3
2 2 )

Is there a simple way to update the test_user tables without doing a select into (and destroying all other data I have in the table.)

As I told you this is probably an super simple question but I cannot get it right?

hope you guys can help me!

Colin Angus Mackay13-Aug-04 12:50

13-Aug-04 12:50

What do you mean it is destroying all the other data in the table? What is your existing UPDATE query?

blopf15-Aug-04 4:19

blopf

15-Aug-04 4:19

What I mean is that if I do the select with an select into statement it will create a new table for me with the result. I dont have an update statement, because all the ones I tried generates errors Frown | :(

Mike Dimmick15-Aug-04 9:11

Mike Dimmick

15-Aug-04 9:11

UPDATE test_user
SET no_answered = SUM(answered)
FROM test_answer
WHERE user_id = test_answer.user_id

I haven't tested this, but it's along these lines.

Stability. What an interesting concept. -- Chris Maunder

SQL Server 2005 Notification Services

EdbertP15-Aug-04 22:33

EdbertP

15-Aug-04 22:33

I'm not particularly sure that this is what you want.
You want to update or insert into the test_user table depending on the records in test_answer, right?
If that is the case, this might be the answer:

INSERT INTO test_user (user_id, time_answered)
(
SELECT user_id, SUM(answered)
FROM test_answer
WHERE answered = 1 AND user_id NOT IN (SELECT user_id FROM test_user)
GROUP BY user_id
);

UPDATE test_user
SET time_answered = SUM(answered)
FROM test_answer
WHERE test_answer.user_id = test_user.user_id;

James Coleman13-Aug-04 7:50

James Coleman

13-Aug-04 7:50

THE SHORT VERSION OF THE QUESTION
How would I leverage SQL Server 2005 Notification Services to notify my asp.net page (or control) that the data it has cached is out of date? The Notification Samples get into specific data (stock prices) being updated past a target value which is a little too detailed for what I want. I just want to be notified when a table change has occured and should expire my cache that is dependant upon that data.

THE LONG VERSION OF THE QUESTION
So I have been reading up on new ways to cache with ASP.NET 2.0 and came across a good article regarding it here: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnvs05/html/SecFeatNT2.asp

It has a note in the article that states:
Note Microsoft SQL Server 2005 supports a completely different method of SQL Cache Invalidation. You can configure SQL Server 2005 to notify your ASP.NET application whenever changes have been made to a database, a database table, or a database row. This means that the ASP.NET Framework does not need to constantly poll a SQL Server 2005 database for changes.

After looking around for quite a while I discovered Notification Services within SQL Server 2005 which is rather cool in that instead of the ASP.NET application polling the server every so often it actually subscribes to the Notification Service and is notified if the event has occurred.

There are some Notification Services samples that one can install and play around with and I found the framework to be pretty flexible and like it a lot. However, I am still a little confused on how to accomplish the approach in the ASP.NET caching article using Notification Services.

Any direction or help would be appreciated.
-james

___________________________
J A M E S C O L E M A N
Practice Director, Microsoft
AGENCY.COM
jcoleman@agency.com
http://www.agency.com

Comlex Query vs Multiple Queries

iamalik13-Aug-04 6:41

iamalik

13-Aug-04 6:41

Hi Everybody

Is it better to apply a single complex query than multiple queries.

Has Any body any idea

Chris Meech13-Aug-04 6:49

Chris Meech

13-Aug-04 6:49

Perhaps if you broke your complex question into multiple understandable questions, someone will provide an answer. Smile | :)

Chris Meech

I am Canadian. [heard in a local bar]

I think people should be required to have an operator's permit to use the internet. John Simmons

I have a feeling that if the millions of man hours wasted every year by geeks trying to get various video and sound cards working under Linux were put into some useful endeavor we'd have solved world hunger, we'd have peace and aids would be no more. [JOS poster]

iamalik13-Aug-04 7:14

iamalik

13-Aug-04 7:14

I wanna fetch some data from a database. The data I want is lying in different tables.

My Question is

Is it better to use a single query containing joins than using different queries to fetch that data

Colin Angus Mackay13-Aug-04 12:54

13-Aug-04 12:54

Use the joins. Joins are not in themselves complext, however the data model can be.