I am running into issues with out of memory exceptions . I need to display a large set of data in a cross tab. I need to display 5,277,888 rows aggregated into 403,920 rows. I don't think birt can handle this and would like some advice.
These are the options I was thinking
Some how fetch some data at a time and aggregate it (might still run out of memory)
Find a different reporting framework that renders html
Not use cross tab and do all of the aggregation server side and try to display it in a sudo cross tab.
Fetaching large amonunt of data and providing it to BIRT increases data trafic and also many a times (as in your case) lead to system / report engine hang.
What you are thinkning is correct. (Option 3) It is preferable to use aggregate functions in your db and give an already summarized data to BIRT at times.
SQL provides options for cross tab outputs (SQL Pivot Function) as well in case required.
Related
I am using DataTable plugin in Laravel. I have a record of 3000 entries in some
But when i load that page it loads all 3000 records in the browser then create pagination, this slow down the page loading.
How to fix this or correct way
Use server-side processing.
Get help from some Laravel Packages. Such as Yajra's: https://yajrabox.com/docs/laravel-datatables/
Generally you can solve pagination either on the front end, the back end (server or database side), or a combination of both.
Server side processing, without a package, would mean setting up TOP/FETCH or make rows in data being returned from your server.
You could also load a small amount (say 20) and then when the user scrolls to the bottom of the list, load another 20 or so. I mention the inclusion of front end processing as well because I’m not sure what your use cases are, but I imagine it’s pretty rare any given user actually needs to see 3000 rows at a time.
Given that Data Tables seems to have built-in functionality for paginating data, I think that #tersakyan is essentially correct — what you want is some form of back-end filtering or paginating of rows of data to limit what’s being sent to the front end.
I don’t know if that package works for you or not or what your setup looks like, but pagination can also be achieved directly from a DataBase returning data via the SQL (using TOP/FETCH for example) or could be implemented in a Controller or Service by tracking pages of data and “loading a page at a time” both from the server and then into the table. All you would need is a unique key to associate each "set of pages" for a specific request.
But for performance, you want to avoid both large data requests and operations on large sets of data. So the more you limit how much data is being grabbed or processed at any stage of your application using it, the more performant your application will be in principle.
I inherited a report from a developer where he combined 5 reports into one SSRS report. It looks like he just copied and pasted each tablix from the original reports one below the other. This was done so that when the user exports to Excel they can have each report on a separate tab. I've never done a multiple SSRS report like this before so I'm just now analyzing how this whole thing works. A major problem I'm finding is that it runs extremely slow, about 10 minutes, seemingly because it has to run all 5 queries. Each stored procedure is listed separately as a data set. Does anyone know a better way to create multiple SSRS reports onto one page, or at least how to make this thing faster?
The first step to improving performance for an SSRS report is to determine what the bottleneck is. Run a query against the view named ExecutionLog4 in the ReportServer database. For each recent execution of a report, the view will give you a record that includes 3 critical fields: TimeDataRetrieval, TimeProcessing, and TimeRendering.
TimeDataRetrieval indicates how long (in milliseconds) it takes for all of the queries to run and return your datasets. If this number is high, then you will need to tune your queries or eliminate some of them to improve performance. You can run a profiler trace to identify which of the procedures is running slowly.
Keep in mind also that subreports fire their dataset queries each time they are rendered in the report. So even a minor performance hiccup in a subreports dataset gets magnified by the number of executions.
TimeProcessing indicates how much time the report server spends manipulating the retrieved data. If this number is high, you may want to consider performing aggregate calculations that are being run many times within a report to run on the SQL side.
TimeRendering indicates how long the server takes to actually render the report. If this number is high, consider avoiding or simplifying expressions used on visual properties that repeat over and over again. This scenario is less common than the other two, in my experience.
Furthermore, here are some tips I've picked up that help to avoid performance issues:
-Avoid using row visibility expressions if you expect a large number of rows to be returned.
-Hiding an object does not prevent dataset execution. If your datasets have similar structure, consider combining them and using object filters to limit what is displayed in different sections. Or use an IF statement in your stored procedure if you only intend to display one of several choices depending on data or parameters.
-Try to limit the number of column groupings in a large tablix. For each grouping in a tablix, you multiply the number of rows of data that may be returned to pivot into those groupings.
More info on SSRS performance can be found at
https://technet.microsoft.com/en-us/library/bb522806(v=sql.105).aspx
This was written for 2008R2, but seems mostly applicable to 2012 as well.
Give all that a shot, then post back here with a more specific question if you get stuck.
I have an interactive report in one of my APEX application. The SQL query used in the IR runs pretty fine when executed in SQL Developer.
But, at times in the application it gets stuck and requires more time than usual to load the IR. (Usually it takes less than 5 secs to load but at times more than 50 secs).
What might be the possible reasons for it to load slow ?
The query is well tuned and IR has default settings with no modification. I have also checked the stats on the tables and it is fresh.
The SQL query used in IR fetches 10k records.
If you go into Component View and then click Interactive Report under Regions, there is a setting near the bottom under the Performance heading called Maximum Rows To Process. Also limiting the number of rows to display sped things up for me.
Sorry but i can't write comments. Is there any database view in your query?
I have similar situation where query from database view with 6 mil. records take around 3 min to complete in Oracle Apex IR and 10-15 seconds in SQL Developer. So after some research i try to put sql from view directly into IR and result was almost same as this in SQL Developer.
Also You can remove pagination from IR or change it from "x to y from z" to be only "x to y".
I hope this can help you.
Query response time in SQL Developer versus any other Web browser cannot be compared directly. Some of the reasons for its slugishness could be related to server setup, server load, current user traffic, page load processes, page and region rendering, number of regions,components and plugins, navigation menu query, report query, number or columns and rows being displayed, row content length, apex items especially LOV with SQL queries, etc.
From your question, it looks like performance issue is not consistent and so, I think issue may be related to server setup or traffic. Try to check if you see any difference in load time after bouncing the server, if that's an option. Try to isolate the problem and if the issue is specific to interactive report, build a classic report and compare times.
Another thing that has helped me in past is to compare and verify compute times using APEX Debugger, here is the screenshot.
Also look at network and timeline tabs in Chrome debugger,
Implement indexes on your tables
Verify with your DBA if you have database locks
Verify the amount of logs in Database
Switch to classic reports.
Regards
We have a TDBGrid that connected to TClientDataSet via TDataSetProvider in Delphi 7 with Oracle database.
It goes fine to show content of small tables, but the program hangs when you try to open a table with many rows (for ex 2 million rows) because TClientDataSet tries to load the whole table in memory.
I tried to set "FetchOnDemand" to True for our TClientDataSet and "poFetchDetailsOnDemand" to True in Options for TDataSetProvider, but it does not help to solve the problem. Any ides?
Update:
My solution is:
TClientDataSet.FetchOnDemand = T
TDataSetProvider.Options.poFetchDetailsOnDemand = T
TClientDataSet.PacketRecords = 500
I succeeded to solve the problem by setting the "PacketRecords" property for TCustomClientDataSet. This property indicates the number or type of records in a single data packet. PacketRecords is automatically set to -1, meaning that a single packet should contain all records in the dataset, but I changed it to 500 rows.
When working with RDBMS, and especially with large datasets, trying to access a whole table is exactly what you shouldn't do. That's a typical newbie mistake, or a borrowing from old file based small database engines.
When working with RDBMS, you should load the rows you're interested in only, display/modify/update/insert, and send back changes to the database. That means a SELECT with a proper WHERE clause and also an ORDER BY - remember row ordering is never assured when you issue a SELECT without an OREDER BY, a database engine is free to retrieve rows in the order it sees fit for a given query.
If you have to perform bulk changes, you need to do them in SQL and have them processed on the server, not load a whole table client side, modify it, and send changes row by row to the database.
Loading large datasets client side may fali for several reasons, lack of memory (especially 32 bit applications), memory fragmentation, etc. etc., you will flood the network probably with data you don't need, force the database to perform a full scan, maybe flloding the database cache as well, and so on.
Thereby client datasets are not designed to handle millions of billions of rows. They are designed to cache the rows you need client side, and then apply changes to the remote data. You need to change your application logic.
I have a stored procedure that returns about 50000 records in 10sec using at most 2 cores in SSMS. The SSRS report using the stored procedure was taking 20min and would max out the processor on an 8 core server for the entire time. The report was relatively simple (i.e. no graphs, calculations). The report did not appear to be the issue as I wrote the 50K rows to a temp table and the report could display the data in a few seconds. I tried many different ideas for testing altering the stored procedure each time, but keeping the original code in a separate window to revert back to. After one Alter of the stored procedure, going back to the original code, the report and server utilization started running fast, comparable to the performance of the stored procedure alone. Everything is fine for now, but I am would like to get to the bottom of what caused this in case it happens again. Any ideas?
I'd start with a SQL Profiler trace of both the stored procedure when you execute it normally, and then the same SP when it's called by SSRS. Make sure you include the execution plans involved, so you can see if it's making some bad decisions (though that seems unlikely - the SQL Server should execute an optimal - or at least consistent - plan regardless of the query's source).
We used to have cases where Business Objects would execute stored procs dozens of times for no aparent reason and it lead to occasionally horrible performance, though I've never seen that same behavior with SSRS. It may be somewhere to start, though. You'll also see the execution begin/end times - that will make it clear if it's the database layer that's hanging up, or if the SQL Server hands back the data in 10 seconds and then it's the SSRS service that's choking somewhere.
The primary solution to speeding SSRS reports is to cache the reports. If one does this (either my preloading the cache at 7:30 am for instance) or caches the reports on-hit, one will find massive gains in load speed.
You may also find that monthly restarts of SSRS application domain to resolve your issue.
Please note that I do this daily and professionally and am not simply waxing poetic on SSRS
Caching in SSRS
http://msdn.microsoft.com/en-us/library/ms155927.aspx
Pre-loading the Cache
http://msdn.microsoft.com/en-us/library/ms155876.aspx
If you do not like initial reports taking long and your data is static i.e. a daily general ledger or the like, meaning the data is relatively static over the day, you may increase the cache life-span.
Finally, you may also opt for business managers to instead receive these reports via email subscriptions, which will send them a point in time Excel report which they may find easier and more systematic.
You can also use parameters in SSRS to allow for easy parsing by the user and faster queries. In the query builder type IN(#SSN) under the Filter column that you wish to parameterize, you will then find it created in the parameter folder just above data sources in the upper left of your BIDS GUI.
[If you do not see the data source section in SSRS, hit CTRL+ALT+D.
See a nearly identical question here: Performance Issuses with SSRS