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I've started using Raven for my last project. When my boss learned about it, he mentioned it's based on Access and he had very bad experience with multiple users and Access. Now I have to either switch or prove to him he is wrong.
No, it isn't. The confusion is because RavenDB can use ESENT for data storage and ESENT used to be called Jet Blue. It was called Jet Blue because it was originally developed to replace the Jet Red engine which was/is used in Access. The Wikipedia entry is quite accurate about the history and differences.
Laurion's answer is correct, but I also wanted to point out that in Raven you can swap out the ESENT storage engine for another that Oren developed called Munin.
From Ayende's blog post about Munin.
Raven.Munin is the actual implementation of a low level managed storage for RavenDB. I split it out of the RavenDB project because I intend to make use of it in additional projects.
At its core, Munin provides high performance transactional, non relational, data store written completely in managed code. The main point in writing it was to support the managed storage in RavenDB, but it is going to be used for Raven MQ as well, and probably a bunch of other stuff as well. I’ll post about Raven MQ in the future, so don’t bother asking about it.
Munin is a low level api, not something that you are likely to use directly. And it was explicitly modeled to give me an interface similar in capability to what Esent gives me, but in purely managed code.
What's the difference between polling and pulling (if any)?
They're two distinct words. To "poll" is to ask for an answer. To "pull" is to use force to move (actually or conceptually) something towards oneself (again, actually or conceptually).
One "polls" a server when software on a client periodically asks the server for something. One "pulls" data from a database towards client software.
Note that both words have various distinct uses even within the world of computing, but I can't think of any case where they're interchangeable in such a way as to leave meaning unchanged. Low-level device driver code may "poll" an interface to check whether it's ready for some operation, and there's no network traffic involved. In electronics, one "pulls" a signal up or down.
Clients may both "poll" a server and "pull" data from a server, but note that when I use each verb I use different direct objects. It only makes sense to say "pull the server" when you're dragging it across the computer room floor.
Poll is like when Gallup does a poll of the American people. They are querying for specific information by asking a question.
Pull is like what you do to a rope. You want the rope (or a file, or some data) to be in your location, so you pull it towards you.
There is a possible slight difference.
Polling is attempting to request information at set intervals.
Pulling just refers to the fact that you are requesting data from somebody else rather than having them send it to you.
That being said, I've heard them used interchangeably.
With respect to network communications, they both refer to the same scheme, where you are periodically requesting data from an external source. See Pull Technology.
Of course the opposite is Pushing, where data is sent as it becomes available.
A poll is quick request while a pull is a slow demand.
One may poll asking if information is immediately available which can be pulled. The distinction is not that the answer to a poll must be boolean, but that the answer to a poll is quick and readily available or the answer will be denied. A poll implies that a choice is being offered which is contrary to a pull, where no choice is offered. A pull may cause the caller to wait for the information to become available or may offer other means of returning the detailed information to the caller later when it actually becomes available.
So, I want to import, export and modify the database. I have read that I have to do that by XML, but I don't really understand their doc system and I haven't found any good tutorials out there that explain this. I am slowly reading the very expensive and short book which is somewhat answering my questions, but I crave more.
As a second question, I want to have a order system where I can send out information or emails with my own code. I assume this would be some type of plug-in that would override or be called at a certain time. Any info would be helpful.
Some parts of the magento data can be imported/exported via the backend (System->Import/Export), namely products and customers.
If you want to deal with the complete DB - use your DB tool of choice (I prefer mysqldump).
When dealing with exported CSV.. use OpenOffice, from my experience it deals better with the separation characters than Excel.
As for your second question - as far as I understood, you will have to develop a module if you want to do something different than the existing functionality and keep the original mail functions. If you don't want to/have to keep the original functions, you can opt to overwrite the module, which is much easier as far as I can see. Google search for "overriding magento module" should turn up atleast one decent tutorial.
I found what I was looking for here:
(on magento site: Resources -> Magento Core API -> Product API or whichever API you want)
The problem is there is no Order API yet (or none that I've seen)
http://www.magentocommerce.com/wiki/doc/webservices-api/api/catalog_product#examples
This details how you'd write an external php script and obtain,edit or delete products (or anything else with an API).
Modules still look daunting, but I am reading through the (very thin) magento book (the only one available).
I hope this helps someone else.
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We currently use ActiveReports (by Data Dynamics, now Grape City) for canned reports, but are considering moving up to their Reports package. If you've used it, I'd love to hear your take on:
Performance - do you feel it will scale well for a web based app (particularly compared with ActiveReports)
Export to Excel - it appears to provide a much cleaner export to Excel (ActiveReports' Excel export is awful, our biggest reason for considering a switch)
Other pros/cons (my company is pretty small, the $3,000 for 2 licenses is a lot for us)
Here are some additional information for you to consider about ActiveReports & Data Dynamics Reports:
ActiveReports Licensing:
There license is per developer. There are no royalties. You can write as many applications as you want and deploy your application to as many users or as many servers as you want without any additional costs. Read the ActiveReports License agreement here.
Reporting to Excel:
First of all, schooner is absolutely correct that all the other reporting tools have a poor scenario when exporting to excel. We recognized the same after many years of experience with ActiveReports. Frankly, it is a very hard problem to take reports designed to be paginated or deployed on the web and put them into a cell-based layout of a spreadsheet.
However, with Data Dynamics Reports', we took a completely different approach. Instead of creating just another "export to Excel", where we look at "paginated" report output and try to fit it into a spreadsheet somehow, we generate the excel output based on two things: A template and the actual data in the report.
By using a template, which is actually a specially formatted excel sheet (cells have some special place holders in them) the reporting engine can output the report's content to an excel sheet completely independent of how the report is laid out when paginated. We call this concept a "Transformation Extension" for Excel since it takes the report's content and transforms it to excel based on a template.
By default DDReports will generate a default template that you will find more often than not has pretty good output. However, if the excel output is not what you want, you can instruct DDReports to save the template so you can customize the output in excel.
The best way to get an introduction to this is to watch the screencast for the Excel Transformation Extension in Data Dynamics Reports here. Jump to about 1:20 in the screencast if you get impatient and see an example of a simple template. Keep in mind this is a very simple template and the possibilities are much more sophisticated. Unfortunately, thus far we haven't published very good documentation on using the excel transformation extension template syntax yet, but let me know if you have questions and I'll help you out! Just comment on this post or send an email to our support team.
Scott Willeke
Data Dynamics / GrapeCity
I've used it and it rocks! It has a Report Designer control that allows you users to build thier own reports on the fly and supports multiple datasources used in a single reports. Best reporting tool on the market bar none.
We use both products and they are quite different from each other. I have been a long time user of Active Reports and have loved them. But when it came time to select a .net reporting tool we did not want to spend a bunch of $$ so we decised to get their DDR product. It took me a couple of weeks to get used to it as I kept trying to use it like Active Reports. Not a good idea. Anyways, once you get used to it it does a decent job. there are some things that they need to do to improve the product. Here are the things that stand out.
You cannot access the control collection in the code area. This is a huge problem if you want to change anything like data binding inside the report.
The database connection have to be refreshed if you repopen the report int he designer. This took a while to figure out and we wondered why our fields would not show up in the preview mode when re reloaded the report.
Their new tech support is terrable. They were bought out recently and now when you call tech supprt you get someone tht has no knowledge that always tells you that someone will call you back. 80% of the time you get no call back. The otehr 20% of the time you get a sample emaild to you that has nothing to do with your issue. Now this is accorss the board with both products. THey used to have great tech support. I hope they fix this.
Those are the main problems and I know they are workign to solve the issues. Like i said we use boh DDR and Active Reports. If you need to do complicated reports stick with Active Reports. If they are simple and you do not want to spend a lto fo money then DDR works fine. I see DDR getting better with each release but it will take a while to get the knks worked out.
Just my opinion
I've only used ActiveReports as well, but their web licensing model is a bit expensive in general in my view, espeically if you need to develop multiple apps on multiple servers. Then there is the per developer costs as well.
I use DevXpress XtraReports and have been fairly happy with it so far and it has some fairly decent export functionality and a much better licensing model.
Regarding export to Excel, I've not seen any reporting tool do it well, mainly due to the formatting issues with the report itself. What we typically do is provide the formatted report to the user, along with an additional link for an Excel export which is a similar but different query with the raw data the report uses.
Another option over formatted printable reports is using grids such as Infragistics which allow you to do sorting, grouping, summaries, and which has excellent Excel export features.
This is to give more information to Bill's response in this thread. I tried to post a comment, but ran out of room :)
Bill Thanks for your honest assessment. Let me give some comments for you from the inside on the issues you mentioned:
1: Admittedly it is not quite as intuitive to access the controls collection as it was with AR, but you /can/ do it. You need to do it outside of the report (not in the script/code embedded into the report). To do it you can load the rdlx file in a ReportDefinition object. For example:
var rpt = new DataDynamics.Reports.ReportDefinition(new FileInfo("myfile...rdlx"));
var list = (DataDynamics.Reports.ReportObjectModel.List)rpt.Report.Body.ReportItems["myList"];
var txt = (DataDynamics.Reports.ReportObjectModel.TextBox)list.ReportItems["myTextBox"];
txt.Value = "=Fields!MyField.Value";
However, depending on the scenario you're after there may be a better way to handle this than changing the binding on the control/reportItem itself. It is difficult to say more without knowing more about your particular scenario/goals.
2: There was recently some discussion I was involved in on how to improve this in the very near future. The dev team was gathering use cases and doing some investigation on various caching strategies to keep hitting the database to an absolutely minimum in the designer. So look for improvements in this area in an upcoming build.
3: Unfortunately, we're working through some challenges with our new technical support team. However, we are improving constantly and we're working hard to bring up the new guys as quickly as possible. If you have a problem with one of your incidents with support feel free to email me personally with your case number and I'll work to try get your case escalated or help out in any way I can (scott dot willeke at grapecity dot com).
Thanks again for your feedback, my next letter is an internal one based on your feedback to help us improve!
Scott Willeke
Program Manager
Data Dynamics / GrapeCity inc.
I have used this product since 2004. Great performance, licensing was great. The migration from earlier versions was great. It had its flaws like ghost images for high speed high volume in production environment and missing some of the goodies you get with Crystal and bar codes issues. But this the engine was fast. Then came version 7. What a mess!! rendering a 4 x 4 label went from 320 ms to 800 ms. Try getting a patch... Good luck with that. Try getting someone on the phone suddenly became like winning lottery. If performance is not a factor and you need just simple reports, go for it. Otherwise, think twice. As for us, this is the last version if our QA can pass it. We're shopping for a replacement product.
They are good and I am not trying to frighten you, but below is the fact, in my perspective :
Pros
Active Community ... you can expect responses overnight.
Good stuff to get you started - walkr-thrus, tutorials, examples, vides etc
Internal builds - Just like Linux kernel patches you can get "hot fixe" for the problems their developer team was able to solve
Web report viewer is available and also works within Visual Studio - just like other reporting tools.
Cons
Week rendering engines - you can not expect that they are going to be exported to word/excel w/o any issues, if you use a sub-report in a table row.
Poor bug fixes - takes over a year to fix a bug - I am following one since 11-11-2011, still they keep saying "we will let you know as soon as we fix this bug"
Not too active to release stable versions. - It takes a year some times for the, to release the next stable version.
Low control over rendering, you may not use events if you wish to embed some code, but yes, Data Dynamics does provide VB.net (and just VB.net ! ) (Custom Code) support, you may use it for validation typo stuff
I am sharing some links for your reference:
forums | How to section | Walkthrough(s) | Useful resources | drill throughs | videos | Convert Crystal reports (Remember: vice versa is not possible) | online help / Documentation - User Guide | Web Report Viewer
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I have been looking for cloud computing / storage solutions for a long time (inspired by the Google Bigtable). But I can't find a easy-to-use, business-ready solution.
I'm searching a simple, fault tolerant, distributed Key=>Value DB like SimpleDB from Amazon.
I've seen things like:
The CouchDB Project : Simple and distributed, fault-tolerant Database. But it understands only JSON. No XML connectors etc.
Eucalyptus : Nice Amazon EC2 interfaces. Open Standards & XML. But less distributed and less fault-tolerant? There are also a lot of open tickets with XEN/VMWare issues.
Cloudstore / Kosmosfs : Nice distributed, fault tolerant fs. But it's hard to configure. Are there any java connectors?
Apache Hadoop : Nice system which much more then abilities to store data. Uses its own Hadoop Distributed File System and has been testet on clusters with 2000 nodes.
*Amazon SimpleDB : Can't find an open-source alternative! It's a nice but expensive system for huge amounts of data. And you're addicted to Amazon.
Are there other, better solutions out there? Which one is the best to choose? Which one offers the smallest amount of SOF(Singe Point of Failure)?
How about memcached?
The High Scalability blog covers this issue; if there's an open source solution for what you're after, it'll surely be there.
Other projects include:
Project Voldemort
Lightcloud - Key-Value Database
Ringo - Distributed key-value storage for immutable data
Another good list: Anti-RDBMS: A list of distributed key-value stores
MongoDB is another option which is very similar to CouchDB, but using query language very similar to SQL instead of map/reduce in JavaScript. It also supports indexes, query profiling, replication and storage of binary data.
It has huge amount of documentation which might be overwhelming at fist, so I would suggest to start with Developer's tour
Wikipedia says that Yahoo both contributes to Hadoop and uses it in production (article linked from wikipedia). So I'd say it counts for business-provenness, although I'm not sure whether it counts as a K/V value database.
Not on your list is the Friendfeed system of using MySQL as a simple schema-less key/value store.
It's hard for me to understand your priorities. CouchDB is simple, fault-tolerant, and distributed, but somehow you exclude it because it doesn't have XML. Are XML and Java connectors an unstated requirement?
(Anyway, CouchDB should in fact be excluded because it's young, its API isn't stable, and it's not a key-value store.)
I use Google's Google Base api, it's Xml, free, documented, cloud based, and has connectors for many languages. I think it will fill your bill if you want free hosting too.
Now if you want to host your own servers Tokyo cabinet is your answer, its key=>value based, uses flat files, and is the fastest database out there right now (very barebones compared to say Oracle, but incredibly good at storing and accessing data, about 1 million records per second, with about 10bytes of overhead (depending on the storage engine)). As for business ready TokyoCabinet is the heart of a service called Mixi, which is the equivalent of Japan's Facebook+MyPage, with several million heavy users, so it's actually very battle proven.
If you want something like Bigtable, you can't go past HBase or Hypertable - they're both open-source Bigtable clones. One thing to consider, though, is if your requirements really are 'big enough' for Bigtable. It scales up to thousands of tablet servers, and as such, has quite a bit of infrastructure under it to enable that (for example, handling the expectation of regular node failures).
If you don't anticipate growing to, at the very least, tens of tablet servers, you might want to consider one of the proposed alternatives: You can't beat BerkelyDb for simplicity, or MySQL for ubiquity. If all you need is a key/value datastore, you can put a simple 'dict' wrapper around your database interface, and switch out your backend if you outgrow one.
You might want to look at hypertable which is modeled after google's bigtable.
Use The CouchDB
Whats wrong with JSON?
JSON to XML is trivial
You might want to take a look at this (using MySQL as key-value store):
http://bret.appspot.com/entry/how-friendfeed-uses-mysql
Cloudera is a company that commercializes Apache Hadoop, with some value-add of course, like productization, configuration, training & support services.
Instead of looking for something inspired by Google's bigtable- Why not just use bigtable directly? You could write a front-end on Google App-Engine.
Good compilation of storage tools for your question :
http://www.metabrew.com/article/anti-rdbms-a-list-of-distributed-key-value-stores/
Tokyo Cabinet has also received some attention as it supports table schemas, key value pairs and hash tables. It uses Lua as an embedded scripting platform and uses HTTP as it's communication protocol Here is an great demonstration.