What is the maximum database size? Is there a chart that shows maximum database size across different devices? Can you store a pre-populated database on an SD card and plug that into the device and read that database with titanium?
There is no limit (as far as I know besides SQL limits) on the size of a database except available storage on device, but obviously your app wont really function responsively if you have a ridiculous (a million rows) amount of data stored on the device.
The chart would just be comparing phone flash memory.
Probably, but there hasn't been a lot of success. Check here, and here and here.
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I've been hearing conflicting statements on how much records / data size, tableau can handle.
In the last week two people have told me they have dashes which are, 100m and 600m records. They do incremental refreshes.
If I have a dash with xxx million records. Do clients only receive the data that is in their aggregated view.
So, if I have a source with 200million records. In the dash it shows the aggregated total per week per product. Let's say this is 400 cells(underneath it's millions of records). Is the client only receiving 400 data points.
If I then add filters to sub product or user level data, would that mean all of these data is imported due to the filters? If this is the case, how does this affect speed?
Ultimately, Tableau can handle as much data as your datasource can handle. If you are set up so Tableau connects to a datasource directly, only the results of a query are transmitted to the user. I've got billion row datasources in BigQuery that return reasonably fast aggregated numbers to Tableau.
If your datasource is not fast then this won't give good results in Tableau.
If you are using extracts, where, in effect, Tableau pulls all the data locally, things will usually be faster, but you will have local drive and memory limits on the size of the dataset. And each user will need an extract. Unless you are using Tableau server in which case the extract can be on the server.
Dashboards built on big datasources sometimes get slow when there are a lot of filters because populating each filter requires a datasource query (which may be triggered every time you use a filter). There are strategies to speed up dashboards with this problem by using partial extracts that generate all the values used for filtering (you can sometimes use parameters for a similar speed gain). Or even just designing the filters intelligently. But speed is usually the limiting factor not the size of the source table.
The only real limit on how much Tableau can handle is how many points are displayed. And that depends on RAM. In my experience a 4GB machine will choke on a chart will a couple of million points (e.g. a map plotting every postcode in the UK). But on a 16GB RAM machine I have never found a limit other than how fast the points are drawn.
I was wondering if there are memory limits for metro style apps. I am not talking about the RAM. That I already found out has a limit of 150 mb, right?
I want to know, if there is a restriction of using the local memory (the hard discstorage). I am creating a database to save alot of data. Can i do so until the device runs out of storage? (I am not actually planning to do so. But occupying like 80mb of the memory would be nice)
Thanks in advance.
There is no limit on local data.
Local application data should be used for any information that needs to be preserved between application sessions and is not suitable type or size wise, for roaming application data. Data that is not applicable on other devices should be stored here as well. There are no general size restriction on local data stored. Location is available via the localFolder property. Use the local app data store for data that it does not make sense to roam and for large data sets.
From here. There is a limit on roaming data. Same document has that.
I am working on a mobile game that uses Couchbase mobile on the client and Iris Couch to store data on the cloud. In order for the app to work off line each user has a database on the server which is replicated on the device. Everything looks promising except for one detail: when the data is replicated on the deice it takes too much disk space. For example, a remote database contains 400 documents and it is approximately 100 MB, the replicated database on the device is approximately 390 MB with the same number of documents. Has anyone experienced such issue? Any help would be appreciated.
TouchDB stores data in a completely different format than CouchDB — it actually writes into SQLite tables. Another factor that may be coming into play is the lack of snappy compression on the TouchDB side, which CouchDB recently added and significantly decreased its on-disk requirements.
Considering your documents seem to be relatively large, I suspect that the difference you are seeing may be mostly compressed vs. raw related. You could try filing a feature request for similar compression to be implemented on the TouchDB project if you can determine that this is indeed where the difference is coming from.
To conserve iPhone power, but allow data transfer over TCP-IP what do I do?
I need to receive a constant stream of data all the time. But I don't want to kill the battery in 4 hours by removing the sleep feature.
thx
In one word you cannot do that, you cannot transfer constant stream of data over TCP-IP. One user closes your app, apple restricts resource access to your app. This is apple way of conserving power. You need not worry about power.
I think this old question of mine would help you - iOS Background downloads when the app is not active
You might be able to reduce power a bit by sending or asking for data in the largest chunks possible consistant with smooth operation of your particular application, as larger data bursts may allow the radios to idle for longer periods between the data transfers; and allowing the wifi and cellular radios to turn off greatly reduces power consumption.
I'm developing a app with a list of products. I wanna let the user have 1 picture for each products.
Now, the problem is what to do next. I think that the best way is that the photos get sync when the user connect to their computer & itunes, and acces them from the app (something like: /photos/catalog/ref1.jpg.
The other option is put them on my sqlite database, but I worry that that get bigger. I have data + picture, data change a lot but pictures are rarely modified (if much, I expect the user take 2-3 new pictures each time).
I would just use the network connection available on the device, and not bother with sync through iTunes.
When you download the images, write them to the apps Documents folder, then load them from there. Network usage vs. disk space will be concern. Keep in mind some carrier networks can be crazy expensive for data transfer.
If the images are named with a systematic format, then you can maintain them by comparing the image identifiers against your data, pruning out the older or irrelevant ones.
Do the math and ballpark just how much disk space you think it would take for a local copy of all the images.