[javascript] JavaScript data grid for millions of rows

I need to present a large number of rows of data (ie. millions of rows) to the user in a grid using JavaScript.

The user shouldn't see pages or view only finite amounts of data at a time.

Rather, it should appear that all of the data are available.

Instead of downloading the data all at once, small chunks are downloaded as the user comes to them (ie. by scrolling through the grid).

The rows will not be edited through this front end, so read-only grids are acceptable.

What data grids, written in JavaScript, exist for this kind of seamless paging?

I suggest you read this

http://www.sitepen.com/blog/2008/11/21/effective-use-of-jsonreststore-referencing-lazy-loading-and-more/

I don't mean to start a flame war, but assuming your researchers are human, you don't know them as well as you think. Just because they have petabytes of data doesn't make them capable of viewing even millions of records in any meaningful way. They might say they want to see millions of records, but that's just silly. Have your smartest researchers do some basic math: Assume they spend 1 second viewing each record. At that rate, it will take 1000000 seconds, which works out to more than six weeks (of 40 hour work-weeks with no breaks for food or lavatory).

Do they (or you) seriously think one person (the one looking at the grid) can muster that kind of concentration? Are they really getting much done in that 1 second, or are they (more likely) filtering out the stuff the don't want? I suspect that after viewing a "reasonably-sized" subset, they could describe a filter to you that would automatically filter out those records.

As paxdiablo and Sleeper Smith and Lasse V Karlsen also implied, you (and they) have not thought through the requirements. On the up side, now that you've found SlickGrid, I'm sure the need for those filters became immediately obvious.

dojox.grid.DataGrid offers a JS abstraction for data so you can hook it up to various backends with provided dojo.data stores or write your own. You'll obviously need one that supports random access for this many records. DataGrid also provides full accessibility.

Edit so here's a link to Matthew Russell's article that should provide the example you need, viewing millions of records with dojox.grid. Note that it uses the old version of the grid, but the concepts are the same, there were just some incompatible API improvements.

Oh, and it's totally free open source.

https://github.com/mleibman/SlickGrid/wiki

"SlickGrid utilizes virtual rendering to enable you to easily work with hundreds of thousands of items without any drop in performance. In fact, there is no difference in performance between working with a grid with 10 rows versus a 100’000 rows."

Some highlights:

• Adaptive virtual scrolling (handle hundreds of thousands of rows)
• Extremely fast rendering speed
• Background post-rendering for richer cells
• Configurable & customizable
• Full keyboard navigation
• Column resize/reorder/show/hide
• Column autosizing & force-fit
• Pluggable cell formatters & editors
• Support for editing and creating new rows." by mleibman

It's free (MIT license). It uses jQuery.

best approach i could think of is by loading the chunk of data in json format for every scroll or some limit before the scrolling ends. json can be easily converted to objects and hence table rows can be constructed easily unobtrusively

Take a look at dGrid:

https://dgrid.io/

I agree that users will NEVER, EVER need to view millions of rows of data all at once, but dGrid can display them quickly (a screenful at a time).

Don't boil the ocean to make a cup of tea.

I used jQuery Grid Plugin, it was nice.

Demos

I recommend the Ext JS Grid with the Buffered View feature.

http://www.extjs.com/deploy/dev/examples/grid/buffer.html

Here are a couple of optimizations you can apply you speed up things. Just thinking out loud.

Since the number of rows can be in the millions, you will want a caching system just for the JSON data from the server. I can't imagine anybody wanting to download all X million items, but if they did, it would be a problem. This little test on Chrome for an array on 20M+ integers crashes on my machine constantly.

var data = [];
for(var i = 0; i < 20000000; i++) {
    data.push(i);
}
console.log(data.length);?

You could use LRU or some other caching algorithm and have an upper bound on how much data you're willing to cache.

For the table cells themselves, I think constructing/destroying DOM nodes can be expensive. Instead, you could just pre-define X number of cells, and whenever the user scrolls to a new position, inject the JSON data into these cells. The scrollbar would virtually have no direct relationship to how much space (height) is required to represent the entire dataset. You could arbitrarily set the table container's height, say 5000px, and map that to the total number of rows. For example, if the containers height is 5000px and there are a total of 10M rows, then the starting row ˜ (scroll.top/5000) * 10M where scroll.top represents the scroll distance from the top of the container. Small demo here.

To detect when to request more data, ideally an object should act as a mediator that listens to scroll events. This object keeps track of how fast the user is scrolling, and when it looks like the user is slowing down or has completely stopped, makes a data request for the corresponding rows. Retrieving data in this fashion means your data is going to be fragmented, so the cache should be designed with that in mind.

Also the browser limits on maximum outgoing connections can play an important part. A user may scroll to a certain position which will fire an AJAX request, but before that finishes the user can scroll to some other portion. If the server is not responsive enough the requests would get queued up and the application will look unresponsive. You could use a request manager through which all requests are routed, and it can cancel pending requests to make space.

The best Grids in my opinion are below:

• Flexigrid: http://flexigrid.info/
• jQuery Grid: http://www.trirand.com/blog/
• jqGridView: http://plugins.jquery.com/project/jqGridView
• jqxGrid: http://www.jqwidgets.com/
• Ingrid: http://reconstrukt.com/ingrid/
• SlickGrid http://github.com/mleibman/SlickGrid
• DataTables http://www.datatables.net/index
• ShieldUI http://demos.shieldui.com/web/grid-virtualization/performance-1mil-rows

My best 3 options are jqGrid, jqxGrid and DataTables. They can work with thousands of rows and support virtualization.

I suggest sigma grid, sigma grid has embed paging features which could support millions of rows. And also, you may need a remote paging to do it. see the demo http://www.sigmawidgets.com/products/sigma_grid2/demos/example_master_details.html

I can say with pretty good certainty that you seriously do not need to show millions of rows of data to the user.

There is no user in the world that will be able to comprehend or manage that data set so even if you technically manage to pull it off, you won't solve any known problem for that user.

Instead I would focus on why the user wants to see the data. The user does not want to see the data just to see the data, there is usually a question being asked. If you focus on answering those questions instead, then you would be much closer to something that solves an actual problem.

(Disclaimer: I am the author of w2ui)

I have recently written an article on how to implement JavaScript grid with 1 million records (http://w2ui.com/web/blog/7/JavaScript-Grid-with-One-Million-Records). I discovered that ultimately there are 3 restrictions that prevent from taking it highter:

1. Height of the div has a limit (can be overcome by virtual scrolling)
2. Operations such as sort and search start being slow after 1 million records or so
3. RAM is limited because data is stored in JavaScript array

I have tested the grid with 1 million records (except IE) and it performs well. See article for demos and examples.

I would highly recommend Open rico. It is difficult to implement in the the beginning, but once you grab it you will never look back.

I kind of fail to see the point, for jqGrid you can use the virtual scrolling functionality:

http://www.trirand.net/aspnetmvc/grid/performancevirtualscrolling

but then again, millions of rows with filtering can be done:

http://www.trirand.net/aspnetmvc/grid/performancelinq

I really fail to see the point of "as if there are no pages" though, I mean... there is no way to display 1,000,000 rows at once in the browser - this is 10MB of HTML raw, I kind of fail to see why users would not want to see the pages.

Anyway...

I know it's an old question but still.. There is also dhtmlxGrid that can handle millions of rows. There is a demo with 50,000 rows but the number of rows that can be loaded/processed in grid is unlimited.

Disclaimer: I'm from DHTMLX team.

Disclaimer: i heavily use YUI DataTable without no headache for a long time. It is powerful and stable. For your needs, you can use a ScrollingDataTable wich suports

• x-scrolling
• y-scrolling
• xy-scrolling
• A powerful Event mechanism

For what you need, i think you want is a tableScrollEvent. Its API says

Fired when a fixed scrolling DataTable has a scroll.

As each DataTable uses a DataSource, you can monitoring its data through tableScrollEvent along with render loop size in order to populate your ScrollingDataTable according to your needs.

Render loop size says

In cases where your DataTable needs to display the entirety of a very large set of data, the renderLoopSize config can help manage browser DOM rendering so that the UI thread does not get locked up on very large tables. Any value greater than 0 will cause the DOM rendering to be executed in setTimeout() chains that render the specified number of rows in each loop. The ideal value should be determined per implementation since there are no hard and fast rules, only general guidelines:

• By default renderLoopSize is 0, so all rows are rendered in a single loop. A renderLoopSize > 0 adds overhead so use thoughtfully.
• If your set of data is large enough (number of rows X number of Columns X formatting complexity) that users experience latency in the visual rendering and/or it causes the script to hang, consider setting a renderLoopSize.
• A renderLoopSize under 50 probably isn't worth it. A renderLoopSize > 100 is probably better.
• A data set is probably not considered large enough unless it has hundreds and hundreds of rows.
• Having a renderLoopSize > 0 and < total rows does cause the table to be rendered in one loop (same as renderLoopSize = 0) but it also triggers functionality such as post-render row striping to be handled from a separate setTimeout thread.

For instance

// Render 100 rows per loop
 var dt = new YAHOO.widget.DataTable(<WHICH_DIV_WILL_STORE_YOUR_DATATABLE>, <HOW YOUR_TABLE_IS STRUCTURED>, <WHERE_DOES_THE_DATA_COME_FROM>, {
     renderLoopSize:100
 });

<WHERE_DOES_THE_DATA_COME_FROM> is just a single DataSource. It can be a JSON, JSFunction, XML and even a single HTML element

Here you can see a Simple tutorial, provided by me. Be aware no other DATA_TABLE pluglin supports single and dual click at the same time. YUI DataTable allows you. And more, you can use it even with JQuery without no headache

Some examples, you can see

• List item

Feel free to question about anything else you want about YUI DataTable.

regards,

I know this question is a few years old, but jqgrid now supports virtual scrolling:

http://www.trirand.com/blog/phpjqgrid/examples/paging/scrollbar/default.php

but with pagination disabled