@swasheck A predominantly random-access workload hides a lot of sins because the throughput is limited by the physical disk seeks. You can hide a lot (but not all) sins in that.
I added a job to reset my database column at 12:00AM every day but now when I make a new query as
USE msdb ;
GO
EXEC dbo.sp_help_jobactivity ;
GO
I don't see any being displayed.
Here were the steps I followed to create and add my job to server sql2012;
On the Server Explorer, right click o...
@swasheck If you want a better reason, unless you really need HA (say 4 9's or better) networked storage is at least an order of magnitude more expensive per IOPS than direct attach storage, and closer to two orders of magnitude if it's not tuned for the workload.
If you want a fast SAN you're up for quite a lot of money changing hands.
Virtualisation is less of a sin than poorly tuned storage, although a badly set up VM can cause grief. I'd disagree with Mr Ozar on his point that virtualisation excuses you from capacity planning. I've seen about 6 sites on the trot that pretty much repudiate that for various reasons.
I even had one outfit describe a blade with 1 four core xeon and 16GB of RAM as a 'supercomputer' (note that the capacity plan for this predicted about 1.5TB of data in 3 years).
@AaronBertrand An ordinary £10,000 SAS array and a host-based RAID controller will blow the socks of a SAN costing 100x the price for a DW workload if the SAN isn't configured right.
@AaronBertrand I had the infrastructure wonk on my current gig talk about how he could get 300 or 400MB/sec off a high-end SAN.
I can get more than that off a single mid 2000's vintage two-channel U320 array if it's tuned right.
And you can get over 1GB/sec off a 2.5" 24 way SAS array if you tune it for a streaming workload.
What really pisses me off is the political shenanigans infrastructure people will go through to avoid having to admit that about £20,000 worth of wintel server and storage will run a DW workload an order of magnitude faster than their £1m consolidation environment.
@ConcernedOfTunbridgeWells it is all political. They fought to get the SAN budget approved, now they're going to make use of it, dammit. Even if it's terrible.
So I've got a stored procedure that the DBAs are reporting was blocked for nearly 10 minutes because of contention in TempDB... This stored procedure usually executes in around 50 - 100 MS... and simply does a select...into #temp of a few hundred rows. TempDB hasn't grown past it's initially allocated size... is there any other typical cause for long blocking involving TempDB?
If you need to fumble your way through xpath, and especially since I'm already using the html agility pack to parse html, this test bed has been just what I needed haptestbed.codeplex.com
@MichaelFredrickson How was it determined that the blocking was tempdb contention? Depending on the precise cause, there are some things you can do. In other cases, not.
Pondering an SSIS task. Task to check if file exist and just delete it if it does. Found Script Task with System.IO.File.Exists handles that well. If found moves to another script task and deletes it. This is the most common method I have seen written up in blogs and on Sql Magazine. Would it not just be quicker to use System.IO.File.Delete? If the file is not there this method will still return success, MSDN states it does not through an exception if the file is not found.
@ShawnMelton I find I am doing things like that when my package is going to retrieve a file and then start processing and I don't know that the previous run went well or cleaned up after itself so I always want a clean slate to start work with. A dirty trick I use is to just have a SQL Agent step do the delete so that I don't have file work in the package proper, just a documentation precursor of "files shouldn't be there before this starts"
@AaronBertrand Partly a joke, but I find ebay is great for development kit and suchlike. Quite often I say 'Ebay is my preferred supplier.' About the only computer equipment I don't buy off ebay is laptops. Note also that not all kit off ebay is secondhand. Quite a few vendors use it as a channel to punt new kit.
I’ve used MySQL on windows7.
I create a database named myDB and it has some tables.
Recently my machine was infected by a virus.
After that SHOW TABLES and SHOW DATABASES statements don’t show any tables and databases but I can see data from tables in myDB with SELECT statements.
I believe so...
I am reading the section of but now there are 300,000 question that users have seen. and assuming he is trying to check over 300k rows to see which ones have been seen.
@dezso, how much depth do you want to go into and what about perennial debates like the relationship between arrays in columns and first normal form?
I mean the levels - I was searching for something describing the different normal forms in human language for educational purposes. This is where Wikipedia fails (and the article linked by @ChrisTravers seems to fit perfectly). Some of its content are quite vague (and don't match other parts).
Is there a way you can change Oracle user password without showing the actual password on the screen? I understand that you can execute ALTER USER user_name IDENTIFIED BY new_password; but this will show the password on screen.
My organization practices split-password for administrator password ...
Question: I've got a couple of people here who have spent years on Adabas and need to come up to speed on SQL Server quickly. Who does decent SQL Server courses?
@dezso Only if they're not actually out to get you
I have 48 columns to display data for each 1/2 hour and the corresponding date. It was all okay and suddenly my client wants to change this such that TO DISPLAY ONLY Maximum value off these 48 columns for each day. I tired Max conversion, pivot, etc etc but in vain.
Currently it's like
Date ...
Think i want populate last 10 question of stackoverflow .
I have a table that keep question list , a table to keep question info , a table to list question asker , and ....
Now think I want to get last then question , so I have to join some tables and get last items by ORDER BY ... DESC LIMIT ...
@Phil It is interesting that the command line client supports it which is actually pretty cool. I think it might be worth getting into PostgreSQL's psql client too
I'm trying to find a reliable, efficient expression to calculate how many decimal digits it takes to write a positive integer.
Mathematically, the number of decimal digits in an integer n is 1 + floor(log(n)), where log is the common logarithm (base 10).
There are several ways to construct an e...
There is a question, that is solved by the author itself, but there remains a follow-up question, that cannot be asked on its own without reading the whole question.
how can I restart that question?
MySQL stored procedure: loop through table, delete rows. Logic problem: won't exit loop beca...
I have a very basic question about the correct settings for connecting from LibreOffice to HSQLDB using JDBC. I wonder if I should post here or on SuperUser?
@dezso OK, thanks. Both places have almost nothing on HSQLDB, and I know so few of the matter that I am not sure whether my question is openoffice-specific or not :( I'll go post there.
@dezso np, I don't know the customs all over the network. We are a small site and have almost no migrations, because we have practically no overlap in topics with other sites.
I believe BigTable is a shared disk architecture as all storage is globally visible to all processing nodes. Does anybody have a good reason to think this is not correct?
I don't know if the title is clear enough. Standard formatting of a text puts every IN member on a different line. It's not highly readable, because it's not compact.
I provide you with an example. I know how to solve it using regex. But I believe toad can help me directly.
AS IS
AND field1 I...
Noting is worse that Hibernate automagically generated SQL. Absolutely ridiculous aliases for each column. Makes the SQL harder to read than my handwriting
Because we are having the same problems as in http://social.msdn.microsoft.com/Forums/en/sqlintegrationservices/thread/e51b775a-8601-491b-8ad4-a71b0f0d59ce we have the following question:
That is when inserting from a flat file source we wmiis the last row from the file.
Can you show us where we...
@ConcernedOfTunbridgeWells Regarding the BigTable comment, the Bigtable: A Distributed Storage System for Structured Data pdf has: "C-Store and Bigtable share many characteristics: both systems use a shared-nothing architecture and have two different data structures"
I am trying to "split" a LibreOffice .odb file into a HSQL database and an OpenOffice document containing forms and macros. I am trying to follow the instructions from this thread:
Within a few minutes you can convert your embedded HSQLDB to a stand-alone HSQLDB which is just a very fine dat...
Individual storage nodes hold a partition of the data, but there is no affinity between processing and storage nodes. A BigTable process can read data from multiple nodes according to one paritioning key and write out to its output according to a different key. There is no local storage.
However, on an Oracle RAC system (which is definitely viewed as shared-disk) any processing node can see any disk. If the SAN has multiple controllers the data is partitioned amongst the controllers but any cluster node can still read data from any controller.
Teradata is a shared-nothing system as each partition is held on a separate server with its own local disk. There is a definite affinity between the disk and the CPU on a Teradata system.
Open to the floor. Google claim BigTable is a shared-nothing system and as it is essentially a distributed key-value pair system you could readily make that claim of the database engine itself.
I've made the assertion that BigTable is a shared-disk system on the basis that its most common implementation (Hadoop) has a parallel processing facility that allows uniform access to the distributed KVP data store with no affinity between the database partitioning and the partitioning of the processing nodes.
You could readily make the argument that this definition conflates the database with the application engine on top of it. OTOH, one would normally expect to see BigTable used in this context.
If you take BigTable as just the storage engine then it would be a shared-nothing system. If you take it in the context of the whole Hadoop system then there is no non-uniformity in the access to storage.
@Phil I'd be happy to go with the view that BigTable as a DB engine itself is a shared-nothing system. You could easily make the case that conflating BigTable with the whole stack isn't the right thing to do.
I have a table with 2 columns (A as bool and B as text), these columns can be:
both are null
if A is False, then B should be null
if A is True, then B should be not null
There are rules. I want to create SP or function to check these rules when row adding or updating (via trigger). What is be...
I am here today to ask for a monumental change.
A section that asks the user what they have tried
I feel that question quality could improve dramatically and members can help others faster, rather than waiting for the OP to post what they have tried or what system/language they are using. I w...
Stack Overflow has successfully borrowed at least one XBox feature (Achievements). I'd like to see another feature borrowed as well.
Let's say I'm playing Halo online and another player is being a bigot. I have the option to add him to a list of ignored users. After doing that, all the racist...
I've got a great UDF for a check constraint. See, it's CLR and it calls out to a webservice hosted on the other side of the Pacific to validate the input. The funny thing is, SQL Server sucks so much balls because I'm always waiting on my data to get inserted. NO LOCK doesn't even help
@jnk and @njk one of you should make your username different. Imagine if there was an AaronBeltland in here and I was talking back and forth with him all the time...
@MikeFal And I don't think I'm following you either ;-). Though I only use twitter to consume information about news, technology and stuff like that, I don't really tweet myself
@ypercube - You've got a fair amount of rep - I suggested to @Phil that he not award the bounty and save his rep to get to 10,000 (mod tools) at least. It's a bit late now but you should really concentrate on getting to 10k as well.
2 DBs having schemas that represent the same semantic objects.
The first one is production DB (Non-RDBMS, in-house implemented in-memory DB with shitload of RAM). Other is Postgres.
Once in a while the production DB is changed (schema upgrade).
Question: what is the best practice to keep DBs of...
@ConcernedOfTunbridgeWells If people tweeted more (instead of talking about tweeter), answers like this (and DBA.SE in general) would gather more audience, don't you think?.
@njk you don't have to change. Just an observation since mentally I actually attributed one of your comments to me earlier as coming from Jason. Could be kind of embarrassing if I joked about it with him in North Haven next weekend and he has no idea what I'm talking about. :-)
Hm, you only need to refresh this page, to prove it :)
@Lamak According to the Blu-ray Association, it was intentional : "Blu" is intentionally spelled without an "e" to allow for a distinctive registration of the trademark name.
@Lamak I used to use unix a lot - around 1990 my dream computer was a sun workstation but I couldn't come even close to affording one. They were seriously expensive back then. In 1990 a midrange SGI box cost nearly as much as a house in my hometown.
It's got bluetooth so I can use a wireless keyboard. Only 2 USB ports.
@ConcernedOfTunbridgeWells it costed much, much more over here. On those times, technology wasn't globalized like now, we got things more than a couple of years later
@Lamak Battery life is just not going to be as good as the little Chromebooks. I'm still not sold on the touchscreen on laptops while using it AS a laptop. I've had a few convertible tablets and it's fine when you are using it AS a tablet, but when using it as a laptop, the only time I used it was laying in bed with the stylus as a scroller and clicker.
@ConcernedOfTunbridgeWells And oddly, only USB 2.0. Even the little Chromebook has a USB 3.0. Which doesn't really matter since you won't likely be using a LOT of data through it.
@CadeRoux yeah, before all the tables boom, I would cringe at the sight of someone touching his screen, and got really upset when someone tried to touch my screen
@CadeRoux That's always been my hesitation with tablets. I was stuck on blackberry for the longest time. I needed a physical keyboard. I still refuse to move to a tablet; because if I need a physical keyboard (be it bluetooth), I may as well just use a laptop
I'd rather just pay $399 for a lower end laptop, throw in a $150 SSD and be done with it
I'm trying to use a KILL statement with a declared variable but it's giving me a syntax error. Is there anyway to not use a constant and programatically change the SPID?
For example:
DECLARE @SPID smallint
SET @SPID = 100
Kill @SPID
BTW this is just an example. I need to run the kill in a loo...
@ConcernedOfTunbridgeWells Exactly - I don't have a problem with the same OS/hardware being convertible a la Windows 8 - but the idea that touch on a desktop or laptop screen is something you could use is laughable. Now when the monitor is on the fridge or on a cabinet or wall, that's different. Or in tablet with two hands or on desk or lap or whatever. There's just no laptop/desktop-touch scenario that really makes sense.
@ConcernedOfTunbridgeWells I think that's actually WHY Surface has that cool stand. Because without a stand to solidify the screen, touch on a laptop DOESN'T WORK.
But a touch screen on a laptop is a pointless item unless it can fold over in a convertable tablet mode. And then it's only useful if your desktop software supports running in a multi-touch tablet mode.
@ConcernedOfTunbridgeWells My convertibles predated multi-touch - Fujistu and HP - but I don't see how MORE fingers on the screen makes the use cases more compelling if you keep dirtying up your primary display AND constantly move it slightly as you are touching it. With a stylus, you could have a very light touch compared to a finger.
@CadeRoux The zoom by touching and dragging your fingers apart is useful (at least in theory) if you have a compositing user interface and limited screen space.
On something the size of an iPhone it makes sense.
Multi-touch screens make smaller portable computers feasible at the expense of sucking for things like text input where you need a keyboard.
@CadeRoux I'll let it sit and percolate for a while. They want over £1,000 for the 32GB model on this side of the pond and I don't want another laptop that much, having just plunked down a substantial amount of money on one less than a year ago.
Although the thinkpad is quite old-school. 'made from girders in Scotland' as a friend once said. It's about twice as heavy as a pixel.
@ConcernedOfTunbridgeWells It's good that we have many paradigms duking it out now, perhaps more than ever, although quite a lot of useful devices have died off.
I successfully deployed a set of SSIS packages to a server, and they were all visible in the SSISDB catalog. However, when I tried to select them as a job step, only a subset of the SSIS packages visible in the SSISDB catalog were visible in list of SSIS packages available for selection as SQL A...
@billinkc Well, if a mugger tried to steal it off me I could hit them with it. If I could get one that would return like Xena's chakram I'd be even happier.
I added a job to reset my database column at 12:00AM every day but now when I make a new query as
USE msdb ;
GO
EXEC dbo.sp_help_jobactivity ;
GO
I don't see any being displayed.
Here were the steps I followed to create and add my job to server sql2012;
On the Server Explorer, right click o...
I’ve used MySQL on windows7.
I create a database named myDB and it has some tables.
Recently my machine was infected by a virus.
After that SHOW TABLES and SHOW DATABASES statements don’t show any tables and databases but I can see data from tables in myDB with SELECT statements.
I believe so...
I have 48 columns to display data for each 1/2 hour and the corresponding date. It was all okay and suddenly my client wants to change this such that TO DISPLAY ONLY Maximum value off these 48 columns for each day. I tired Max conversion, pivot, etc etc but in vain.
Currently it's like
Date ...
Think i want populate last 10 question of stackoverflow .
I have a table that keep question list , a table to keep question info , a table to list question asker , and ....
Now think I want to get last then question , so I have to join some tables and get last items by ORDER BY ... DESC LIMIT ...
I'm trying to find a reliable, efficient expression to calculate how many decimal digits it takes to write a positive integer.
Mathematically, the number of decimal digits in an integer n is 1 + floor(log(n)), where log is the common logarithm (base 10).
There are several ways to construct an e...
There is a question, that is solved by the author itself, but there remains a follow-up question, that cannot be asked on its own without reading the whole question.
how can I restart that question?
MySQL stored procedure: loop through table, delete rows. Logic problem: won't exit loop beca...
I don't know if the title is clear enough. Standard formatting of a text puts every IN member on a different line. It's not highly readable, because it's not compact.
I provide you with an example. I know how to solve it using regex. But I believe toad can help me directly.
AS IS
AND field1 I...
I am trying to "split" a LibreOffice .odb file into a HSQL database and an OpenOffice document containing forms and macros. I am trying to follow the instructions from this thread:
Within a few minutes you can convert your embedded HSQLDB to a stand-alone HSQLDB which is just a very fine dat...
I have a table with 2 columns (A as bool and B as text), these columns can be:
both are null
if A is False, then B should be null
if A is True, then B should be not null
There are rules. I want to create SP or function to check these rules when row adding or updating (via trigger). What is be...
Stack Overflow has successfully borrowed at least one XBox feature (Achievements). I'd like to see another feature borrowed as well.
Let's say I'm playing Halo online and another player is being a bigot. I have the option to add him to a list of ignored users. After doing that, all the racist...
2 DBs having schemas that represent the same semantic objects.
The first one is production DB (Non-RDBMS, in-house implemented in-memory DB with shitload of RAM). Other is Postgres.
Once in a while the production DB is changed (schema upgrade).
Question: what is the best practice to keep DBs of...
I'm trying to use a KILL statement with a declared variable but it's giving me a syntax error. Is there anyway to not use a constant and programatically change the SPID?
For example:
DECLARE @SPID smallint
SET @SPID = 100
Kill @SPID
BTW this is just an example. I need to run the kill in a loo...
