Is Memgraph following openCypher specification? - cypher

I've taken a look at openCypher specs. And I wonder if I can use all of the clauses any principles from openCypher in Memgraph.

Memgraph follows openCypher specifications, but there are some minor differences in implementation. You can find the exact list of differences listed on the Memgraph documentation site.

Related

How to generate understanding of PLSQL package, procedure or function?

we can generate ER diagram in SQL developer which help us in understanding of tables in a better way.
Like this Is it possible we can generate some kind of document which can give us overview of what a package/procedure/function is doing?
I'm asking this because in my project we have very long packages like 10000 lines and to read them consume lot of time. If we can generate some kind of document for understanding it will be very helpful.
As far as my experience is concerned there is no tool available which will generate documentation out of PLSQL code (just by reading the code without any comments).
However, I would like to mention the following tools and you can consider using them if they are of any help.
Pldoc
Pldoc is an open-source utility for generating HTML documentation of code written in Oracle PL/SQL.
http://pldoc.sourceforge.net/maven-site/
However, you will have to provide comments in your packages and functions in PLdoc style to ensure that documentation gets created.
Toad's Code Xpert
http://www.toadworld.com/products/toad-for-oracle/w/toad_for_oracle_wiki/11088.code-complexity-analysis-using-toad
This tool will perform an automated review on your code and provide a report. It will also provide a CRUD matrix which you might find useful.
PLSQL Doc Plugin
https://www.allroundautomations.com/plsplsqldoc.html
Similar to PLdoc.
Natural Docs
http://www.naturaldocs.org/
Open-source documentation generator for multiple programming languages.
There is no silver bullet - you cannot automagically create documentation for code.
Worse - the "auto-doc" tools typically look at comments, but there's no guarantee the comments match the code.
However, "working with legacy code" is a common problem. You might want to read this answer, and the book it refers to.
I'm happy with this (new) tool: https://github.com/teotiger/pldocu
It's limited and I miss some automatic export formats (e.g. html), but you can try to do this by yourself. For me it's okay.

hadoop.mapred vs hadoop.mapreduce?

Why are there two separate packages map-reduce package in Apache's hadoop package tree:
org.apache.hadoop.mapred
http://javasourcecode.org/html/open-source/hadoop/hadoop-1.0.3/org/apache/hadoop/mapred/
org.apache.hadoop.mapreduce
http://javasourcecode.org/html/open-source/hadoop/hadoop-1.0.3/org/apache/hadoop/mapreduce/
Why are they separated out? Is there documentation that clarifies this?
They are separated out because both of these packages represent 2 different APIs. org.apache.hadoop.mapred is the older API and org.apache.hadoop.mapreduce is the new one. And it was done to allow programmers write MapReduce jobs in a more convenient, easier and sophisticated fashion. You might find this presentation useful, which talks about the differences in detail.
Hope this answers your question.

'Queueing' tutorials and documentation?

I'm looking for articles and references that give an overview of 'queueing' (I'm probably not even using the right term here). I'm hoping for an introductory styled guide through a world of Redis, RabbitMQ, Celery, Kombu, and whatever other components exist that I haven't read about yet, and how they fit together.
My problem is I need to queue up background tasks for issued by my Django website, and every blog and article I read recommend different solutions.
Lots of options available to you, and your choice will likely come down to personal preference and what dependencies you feel comfortable installing.
I'll give a vote for Redis. I evaluated RabbitMQ, ActiveMQ, HornetQ, and Redis and found Redis to offer the best mix of ease of installation, simplicity, and performance.
It's technically not a message queue, but the push/pop primitives for the list types provide atomic queue-like operations, so it can effectively be used as a queue. It has worked well for us.
One python specific project on top of Redis you might look at:
http://richardhenry.github.com/hotqueue/tutorial.html
Very simple. But again, all the other options, like Celery, are viable too.
RabbitMQ has a good introduction here: http://www.rabbitmq.com/getstarted.html There's examples in Python, even.
HornetQ has a very good documentation, and it's simple to install.
You can find the documentation at www.hornetq.org, and you would have several examples available with the distribution.

Pl/SQL Package Inline Documentation

I am attempting to more fully document our database packages as an API. What we would like is something like JavaDocs for PL/SQL. I have seen a couple tools out there (pldoc, plsqldoc) but would like to know from people who use them how they compare.
I have used PlDoc and find it really good. I haven't used any other tools so can't compare. I found PlDoc did the basics well. I wanted some more advanced features so I built our own tool that added extensions to PlDoc for more tags. Also I don't just do documentation with it I also generate our package headers using some PlDoc tags (e.g #private).
I recommend you try PlDoc then tweak whatever doesn't meet your needs. It doesn't take that long to set up so its not a huge time investment to try it.
I've been using NaturalDocs for a few years now and have found it easy to install and use.
It's pretty much like JavaDocs and supports multiple languages although I've only used it with PL/SQL.
Very configurable although I've not found it necessary to fiddle with that.

Lucene.Net and Geosearch - is it outthere somewhere?

I've found an interesting article about Lucene and geosearching:
http://sujitpal.blogspot.com/2008/02/spatial-search-with-lucene.html
Is there an equivilant .NET implementation out there that I have been unable to find or do I have to rework the Java-code in his example to fit in the .NET Framework?
I came across this article, as well. I do not see a .NET-specific in my Googling, so I am planning on probably porting this code when the need arises, as well. Right now, I am just getting my feet wet with Lucene.NET and have not gotten to the point that I am comfortable enough with it to start extending it, yet.
The code in the article appears to be a derived example of the conceptual geo-distance functionality outlined in Lucene In Action. Although the book is based on the Java product, it is a great read. The samples port easily and it is full of information.
in the latest lucene.net contrib folder there is spatial contribution to perform geosearch see
https://svn.apache.org/repos/asf/incubator/lucene.net/tags/Lucene.Net_2_9_1/contrib/Spatial.Net/
With Lucene.NET 3.0.3, soon to be released, there is a brand new spatial contrib. See:
http://www.code972.com/blog/2012/05/the-future-of-geo-spatial-searches-with-lucene/
There is worked example at https://www.leapinggorilla.com/Blog/Read/1010/spatial-search-in-lucenenet---worked-example
Regards
Ismail