I am building a custom control to do a lookup and provide a summary of the status of several items in database. There are 20 different statuses, and in order to determine the number for each status, I am doing a NotesDatabase.search to count each status.
This was fine when there were only 2 statuses to check, however the business now want all of them displayed. :)
I'm concerned about the time it will take to do the search, and want to do this in the most efficient manner possible.
Things I have taken into account:
The documents are updated regularly, so I can't really have an agent doing the calcs and the custom control run a lookup for those static values. This would mean data is old.
The results are dependant on the user logged in, doing counts based on their login ID so I can't really have seperate views per person.
Does anyone have a clean suggested solution?
I am about to start testing the 20 searches and will update this with those results, but am expecting it to be very slow.
A
the other option: instead of #DBLookup you go into the view and just run through it end to end using a navigator. That's pretty fast and should be faster than 20x search.
Of course you could update tallies in the QuerySave event and write it into a user specific in memory profile.
So in your QuerySave you would see what Users are loaded in a ApplicationBean and update those. If a user logs in newly then a search in the database is done into the application bean. When a session expires (Session listener) the entry in the ApplicationBean is cleared out.
Instead of 20 searches you actually might be better off with ONE Ajax call. Create a view that is categorized by your status and is collapsed. Then make an Ajax call ...statusview?ReadViewEntries&Outputformat=JSON&count=100. This will give you the 100 status summary entries with a childcount property.
Would that work for you?
Would it be possible to add 20 Status documents, and to update one or more of these documents whenever some condition is met? Each time a document is updated, an agent runs to match with those conditions, in order to update the status.
If there are many updates per day, it's not really efficient.
Related
I want to delete more than 1 million User information in Kentico10.
I tried to delete it with UserInfoProvider.DeleteUser (); (see the following documentation), but it is expected that it will take nearly one year with a simple calculation.
https://docs.kentico.com/api10/configuration/users#Users-Deletingauser
Because it's a simple calculation, I think it's actually a bit shorter, but it still takes time.
Is there any other way to delete users in a short time?
Of course make sure you have a backup of your database before you do any of this.
Depending on the features you're using, you could get away with a SQL statement. Due to the complexities of the references of a user to multiple other tables, the SQL statement can get pretty complex and you need to make sure you remove the other references before removing the actual user record.
I'd highly recommend an API approach and delete users through the API so it removes all the references for you automatically. In your API calls make sure you wrap the delete action in the following so it stops the logging of the events and other labor-intensive activities not needed.
using (var context = new CMSActionContext())
{
context.DisableAll();
// delete your user
}
In your code, I'd only select the top 100 or so at a time and delete them in batches. Assuming you don't need this done all in one run, you could let the scheduled task run your custom code for a week and see where you're at.
If all else fails, figure out how to delete the user and the 70+ foreign key references and you'll be golden.
Why don't you delete them with SQL query? - I believe it will be much faster.
Bulk delete functionality exist starting from version 10.
UserInfoProvider has BulkDelete method. Actually any InfoProvider object inhereted from AbstractInfoProvider has BulkDelete method.
Application: The purposed application has an tcp server able to handle several connections with the robots.
I choosed to work with database/ no files, so i'm using a sqlite db to save information about the robots and their full history, models of robots, tasks, etc...
The robots send us several data like odometry, tasks information, and so on...
I create a thread for every new robot's connection to handle the messages and update the informations of the robots on the database. Now lets start talk about my problems:
The application got to show information about the robots in realtime, and I was thinking about using QSqlQueryModel, set the right query and the show it on a QTableView but then I got to some problems/ solutions to think about:
Problem number 1: There are informations to show on the QTableView that are not on the database: I have the current consumption on the database and the actual charge on the database in capacity, but I want to show also on my table the remaining battery time, how can I add that column with the right behaviour (math implemented) in my TableView.
Problem number 2: I will be receiving messages each second for each robot, so, updating the db and the the gui(loading the query) may not be the best solution when I have a big number of robots connected? Is it better to update the table, and only update the db each minute or something like this? If I use this method I cant work with the table with the QSqlQueryModel to update the tables, so what is the approach that you recommend me to use?
Thanks
SancheZ
I have run into similar problem before; my conclusion was QSqlQueryModel is not the best option for display purposes. You may want some processing on query results, or you may want to create, remove, change display data based on the result for a fancier gui. I think best is to implement your own delegates and override the view related methods - setData, setEditor
This way you have the control over all your columns and direct union of raw data and its display equivalent (i.e. EditData, UserData).
Yes, it is better if you update your view real-time and run a batch execute at lower frequency to update the big data. In general app is the middle layer and db is a bottom layer for data monitoring, unless you use db in memory shared cache.
EDIT: One important point, you cannot run updates in multiple threads (you can, but sqlite blocks the thread until it gets the lock) so it is best to run update from a single thread
In my CouchDB database I'd like all documents to have an 'updated_at' timestamp added when they're changed (and have this enforced).
I can't modify the document with validation functions
updates functions won't run unless they're called specifically (so it'd be possible to update the document and not call the specific update function)
How should I go about implementing this?
There is no way to do this now without triggering _update handlers. This is nice idea to track documents changing time, but it faces problems with replications.
Replications are working on top of public API and this means that:
In case of enforcing such trigger you'll have replications broken since it will be impossible to sync data as it is without document modification. Since document get modified, he receives new revision which may easily lead to dead loop if you replicate data from database A to B and B to A in continuous mode.
In other case when replications are fixed there will be always way to workaround your trigger.
I can suggest one work around - you can create a view which emits a current date as a key (or a part of it):
function( doc ){
emit( new Date, null );
}
This will assign current dates to all documents as soon as the view generation gets triggered (which happens after first request to it) and will reassign new dates on each update of a specific document.
Although the above should solve your issue, I would advice against using it for the reasons already explained by Kxepal: if you're on a replicated network, each node will assign its own dates. So taking this into account, the best I can recommend is to solve the issue on the client side and just post the documents with a date already embedded.
What is the best practice for running a database-query after any document in a collection become of certain age?
Let's say this is a node.js web-system with mongoDB, with a collection of posts. After a new post is inserted, it should be updated with some data after 60 minutes.
Would a cron-job that checks all posts with (age < one hour) every minute or two be the best solution? What would be the least stressing solution if this system has >10.000 active users?
Some ideas:
Create a second collection as a queue with a "time to update" field which would contain the time at which the source record needs to be updated. Index it, and scan through looking for values older than "now".
Include the field mentioned above in the original document and index it the same way
You could just clear the value when done or reset it to the next 60 minutes depending on behavior (rather than inserting/deleting/inserting documents into the collection).
By keeping the update-collection distinct, you have a better chance of always keeping the entire working set of queued updates in memory (compared to storing the update info in your posts).
I'd kick off the update not as a web request to the same instance of Node but instead as a separate process so as to not block user-requests.
As to how you schedule it -- that's up to you and your architecture and what's best for your system. There's no right "best" answer, especially if you have multiple web servers or a sharded data system.
You might use a capped collection, although you'd run the risk of potentially losing records needing to be updated (although you'd gain performance)
I have done a bit of research on pagination and from what i have read there are 2 contradictory solutions of doing it
Load a small set of data from the database each time a user clicks next
Problem - Suppose there are a million rows that meet any WHERE conditions. That means a million rows are retrieved, stored, filesorted, then most of them are discarded and only 20 retrieved. If the user clicks the "next" button the same process happens again, only a different 20 are retrieved.(ref - http://www.mysqlperformanceblog.com/2008/09/24/four-ways-to-optimize-paginated-displays/)
Load all the data form the database and cache it...This has few problems too mentioned here - http://www.javalobby.org/java/forums/t63849.html
So i know i will have to use a hybrid of both..however the question boils down to - Which operation is more expensive -
making repeated queries in database for small chunks of data
or
transferring a large result set over the network
My company has exactly this situation, and we've chosen a bit of a hybrid. Our data is tabular, so we send it via AJAX to datatables This allows for good UI formatting, sorting, filtering, and show/hide of columns. Datatables has a great solution that will "queue ahead" called "pipelining" that will grab a quantity of data ahead of the user's action (in our case, up to 5 times the records they request) then page through without requests until it runs out of data. It's EXTREMELY easy to implement with Datatables, but I suspect a similar solution would not be difficult if you had to write it by hand using jQuery's AJAX functionality.
I tried doing a full load and cache on a 1.5 million record database and it was a trainwreck. The client almost dumped me because they got mad it was so slow. After a solid overnight of AJAX goodness, the client was happy once again. But best never to get to that point.
Good Luck.