sanoj - Page 3 - Developer IT

Is it a good idea to use MySQL and Neo4j together?

- by Sanoj

I will make an application with a lot of similar items (millions), and I would like to store them in a MySQL database, because I would like to do a lot of statistics and search on specific values for specific columns. But at the same time, I will store relations between all the items, that are related in many connected binary-tree-like structures (transitive closure), and relation databases are not good at that kind of structures, so I would like to store all relations in Neo4j which have good performance for this kind of data. My plan is to have all data except the relations in the MySQL database and all relations with item_id stored in the Neo4j database. When I want to lookup a tree, I first search the Neo4j for all the item_id:s in the tree, then I search the MySQL-database for all the specified items in a query that would look like: SELECT * FROM items WHERE item_id = 45 OR item_id = 345435 OR item_id = 343 OR item_id = 78 OR item_id = 4522 OR item_id = 676 OR item_id = 443 OR item_id = 4255 OR item_id = 4345 Is this a good idea, or am I very wrong? I haven't used graph-databases before. Are there any better approaches to my problem? How would the MySQL-query perform in this case?

Read the article

How can I quickly set up a RESTful site using PHP without a Framework?

- by Sanoj

I would like to quickly set up a RESTful site using PHP without learning a PHP Framework. I would like to use a single .htaccess-file in Apache (no mod_rewrite) or a single rule using Nginx, so I easyli can change web server without changing my code. So I want to direct all requests to a single PHP-file, and that file takes care of the RESTful-handling and call the right PHP-file. In example: The user request http://mysite.com/test The server sends all requests to rest.php The rest.php call test.php (maybe with a querystring). If this can be done, is there a free PHP-script that works like my rest.php? or how can I do this PHP-script?

Read the article

How can I do block-oriented disk I/O with Java? Or similar for a B+ tree

- by Sanoj

I would like to implement an B+ tree in Java and try to optimize it for disk based I/O. Is there an API for accessing individual disk blocks from Java? or is there an API that can do similar block-oriented access that fits my purpose? I would like to create something like Tokyo Cabinet in 100% Java. Is there anyone that knows what Java only databases like JavaDB is using in the back-end for this? I know that there are probably other languages than Java that can do this better, but I do this in a learning purpose only.

Read the article

How to get the number of columns from a JDBC Resultset?

- by Sanoj

I am using CsvJdbc (it is a JDBC-driver for csv-files) to access a csv-file. I don't know how many columns the csv-file contains. How can I get the number of columns? Is there any JDBC-function for this? I can not find any methods for this in java.sql.Resultset. For acessing the file, I use code similar to the example on the CsvJdbc website.

Read the article

Do I need a spatial index in my database?

- by Sanoj

I am designing an application that needs to save geometric shapes in a database. I haven't choosen the database management system yet. In my application, all database queries will have an bounding box as input, and as output I want all shapes within that database. I know that databases with a spatial index is used for this kind of application. But in my application there will not be any queries of type "give me objects nearby x/y" or other more complex queries that are useful in a GIS application. I am planning of having a database without a spatial index and have queries looking like: SELECT * FROM shapes WHERE x < max_x AND x > min_x AND y < max_y AND y > min_y And have an index on the columns x (double) and y (double). As long I can see, I don't really need a database with an spatial index, howsoever my application is close to that kind of applications. And even if I would like to have nearby queries, then I could create a big enough bounding box around that point. Or will this lead to poor performance? Do I really need a spatial database? And when is a spatial index needed?

Read the article

How can I draw the control points of a Bézier Path in Java?

- by Sanoj

I have created a Path of Bézier curves and it works fine to draw the path. But I don't know How I can draw the Control Points together with the Path. Is that possible or do I have to keep track of them in another datastructure? I am creating the path with: Path2D.Double path = new Path2D.Double(); path.moveTo(0,0); path.curveTo(5, 6, 23, 12, 45, 54); path.curveTo(34, 23, 12, 34, 2, 3); And drawing it with: g2.draw(path);

Developer IT