I have one table t1 like this
a|b|c
1|1|2
1|1|3
1|2|3
1|2|3
1|3|5
2|3|2
and a second t2 which for every different a knows how many kinds of b there are like
a|num
1|3
2|1
What I need is to get the num value from the second table for a specific a and with that to create multiple selects wit...
I have one table t1 like this
a|b|c
1|1|2
1|1|3
1|1|6
1|2|3
1|2|4
1|2|7
1|3|5
2|3|2
the result should be as if I had multiple selects like this:
(SELECT * FROM t1 where a=1 AND b=1 LIMIT 2)
UNION ALL
(SELECT * FROM t1 where a=1 AND b=2 LIMIT 2)
....
(SELECT * FROM t1 where a=1 AND b=n ...
I have one table t1 like this
a|b|c
1|1|2
1|1|3
1|2|3
1|2|3
1|3|5
2|3|2
and a second t2 which for every different a knows how many kinds of b there are like
a|num
1|3
2|1
What I need is to get the num value from the second table for a specific a and with that to create multiple selects wit...
Looking at these questions, my only concern is age, but it's mitigated by the fact that a) there's not a super amount of rep that's going to be lost on the site during the next recalc b) gbn's answers are typically the highest voted and/or accepted, so it's his own rep, so that's ok in my book.
I just don't know if the mods have had a discussion about what you want with old, accepted answers.
BTW, I don't have a problem with any of these going to dba, btw. I think it's a better home and I don't see huge ramifications by moving these from SO to DBA (not massively upvoted, etc).
I have been asked to create something which tracks the daily cost to collect on accounts, and I am trying to figure out a database table schema that would support this.
Here's what I know
Company has over 2.5 million accounts
Of these, they currently work an average of 200,000 per month (that ...
I have table that holds from very basic info. Just a title and a few date fields.
There's one field called comments which is varchar(4000)
Most of the time we leave it blank, but some times will enter a large amount of data here.
Is this a really bad design? Or is this just slightly inefficient?
...
Working on a new project which has the requirement to use 7 databases. Arguing performance, stability, optimization is easier implemented.
While I don't agree I'm having trouble collecting good arguments to use a single database. (While the 7 databases splits the tables in logical domains)
One ...
I execute a stored procedure with an option "Include Actual Execution Plan". The execution plan always is represented by multiple statements each of which has its own execution plan.
MSDN states the following:
If the statement is a stored procedure
or Transact-SQL statement, it becomes
t...
What is wrong in code. or its results, illustrating that clustered index is evil [1]?
and how to de-debunk, i.e. to return to customary myths and best practices?
[1]
Debunking myths about clustered indexes - part 3 (example script)
http://blogs.sqlserver.org.au/blogs/greg_linwood/archive/2...
On our dev boxes, our database resides entirely in the PRIMARY filegroup, and everything works fine.
On one of our production servers, recently upgraded from 2005 to 2008, we noticed it was performing slower than it should. On this machine, there are two filegroups - PRIMARY and INDEXES. Bot...
I need some help analysing some simple t-sql execution plans.
I have a table [User] with the following 3 columns:
Id(Primary Key), Username(nvarchar(50)), FirstName(nvarchar(50))
I have Created an Unique NonClustered Index for the Username column
The execution plan for a query filtering by Fir...
I'm curious. Is there any way to prevent SQL query execution plans from being cached for an entire connection's duration?
Can I run a command that basically says, "use OPTION(RECOMPILE) for all subsequent commands until I tell you to stop doing so?"
I'm acutely aware of all the performance tra...
Which is faster
SELECT * FROM X INNER JOIN Y ON x.Record_ID = y.ForignKey_NotIndexed_NotUnique
or
SELECT * FROM X INNER JOIN Y ON y.ForignKey_NotIndexed_NotUnique = x.Record_ID
Like I said, I think these are all spot on, I don't see any problems with it, I just want to make sure this is in line with whatever the discussion the mods had recently (and @JackDouglas you should fill me in on TL about that).
What is wrong in code. or its results, illustrating that clustered index is evil [1]?
and how to de-debunk, i.e. to return to customary myths and best practices?
[1]
Debunking myths about clustered indexes - part 3 (example script)
http://blogs.sqlserver.org.au/blogs/greg_linwood/archive/2...
@casperOne only because so far I've noticed a fair few of them getting flagged once they get here ... we don't see all the migrate-in's, altho we probably should stay on top of that, and once reviewed the split is probably more skewed in favor of keep
@jcolebrand I'm a little confused, it seems like some correlation between age of question and on topic is being made, which, as I understand, there is none.
@jcolebrand Could you show me an example of something that was closed as OT which was older? I'd like to see for myself so it can help me understand why it is OT and see if there's a correlation.
and I'm saying "don't take my word for we need to watch stuff over 2 years" to mean "we don't want them" I'm just saying "they probably don't quite match our site here"
@jcolebrand If you come across them, let me know. Also, I'm going to start taking some of the flags I'm seeing on SO and transferring over. There might be 10 or so now, I don't know how fast, but I'd like some feedback on the quality of the migrations.
@jcolebrand It's closed because it's a dupe on this site
@jcolebrand If you want. I'll leave that to you. As long as you think I'm not migrating crap (because there are two answers there) I'm good with whatever approach you want to take.
@casperOne oh I figured something broke, that's all
@casperOne if you're migrating, let's just say a number, 10 Q a day, and I complain about 2 in a month, then I don't think you're doing it wrong sir.
my gut-check was that I seemed to see a lot of flags on old Q, but apparently that's been a month ago or more >.<
I was gonna look in the data.se dump and see, but astoundingly the migrated Q flags have disappeared (it's on meta, it's a known issue, it's being resolved)
So I can't even give you data dump stats
which would be easiest, ya know, since it's a question of data, and queries are good at that sort of thing
NHibernate automatically uses sp_executesql with different paramters to execute it's data. Now what we're noticing in production is that we're beeing hit by parameter sniffing sometimes. In such a way that query performance isn't just effected it's actually causing timeouts.
I'm not a DBA so i'm...
What is wrong in code. or its results, illustrating that clustered index is evil [1]?
and how to de-debunk, i.e. to return to customary myths and best practices?
[1]
Debunking myths about clustered indexes - part 3 (example script)
http://blogs.sqlserver.org.au/blogs/greg_linwood/archive/2...
What are some scenarios (in SQL Server) in which a full table scan is better than an index scan ?
On our dev boxes, our database resides entirely in the PRIMARY filegroup, and everything works fine.
On one of our production servers, recently upgraded from 2005 to 2008, we noticed it was performing slower than it should. On this machine, there are two filegroups - PRIMARY and INDEXES. Bot...
Is there a measure of time frame as to which the execution plan of inline queries will cached?
