Here is the problem: http://en.wikipedia.org/wiki/Partition_problem

Any weighted set can be partitioned. A weighted set can be represented in a sparse way as a space and time optimization. Also duplicates are removed, making it easy to at least partially partition any problem by hash.

For example, you can distribute the subset sum problem over multiple machines when you reduce the set to unique values and hash on the value (weighted set). This allows you to distribute checks, reducing complexity.

You can partition the problem into even and odd items, the absolute value of the items, etc, and add many simple checks which can be tested during insertion instead of after a huge list has been created inside the database. Using distributed computation of combinatorial algebra (sum) you can aggregate the data with your load, allowing you to answer questions on the data while it is loaded. The check will fire as soon as an …

This will just be a short reminder. If you're planning to create multiple-column indexes in MySQL, remember that the order of the columns matters. As the MySQL documentation points out, any "leftmost prefix of the index can be used." This means that the index can be used for any number of columns in a where clause as long as those columns are at the beginning of the index column list and in the same order.

Let me just start off this post saying if you're not interested in InnoDB tablespace internals, then this might not be the post for you. :)

At any rate, whilst examining individual tablespace files (the .ibd file created when running with innodb_file_per_table option enabled) in their binary format, I noticed the initial page size for a individual tablespace did not appear to be 16k (as the default InnoDB page size is 16k).

Upon examining the actual binary data stored in the data file (just create a basic table and insert 10 rows), you can see data is written at the very beginning of the file (position 0).

One can also see data appearing at several (4) other places in this file.

I was trying to sync up what I was seeing with these InnoDB internals:

…

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Effective June 1, 2011, MySQL certification exams will be offered exclusively through a new test delivery partner — Pearson VUE — and will no longer be available through Prometric. This will consolidate all Oracle Certification exams within the operations of a single testing vendor so we can provide better service and global testing coverage for these Oracle certification exams. Pearson VUE currently has over 5,000 test centers worldwide in 165 countries.

To help prepare you for this transition, here are some important dates for you to be aware of:

• If you are currently following a certification path and are planning to take an exam on/after June 1: Registration has began at Pearson VUE on May 16, 2011 for all scheduled exams on or after June 1. Visit pearsonvue.com/oracle to create a new web account and get started.
• …

One of the issues Web Developers face is making their application robust to prevent SQL injection attacks. Different approaches exist which help. Sometimes people use large abstraction layers (which, sometimes, don't make anything safe ...) and sometimes people use prepared statements as a way to secure queries. Now prepared statements were a nice invention some 30 years ago abut they weren't meant for making things secure and so they do have some shortcomings: One issue is that preparing and executing a query adds a round-trip to the server where it then requires resources. In a classic application this is no issue. The users starts the application up early in the morning and processes data multiple times so the prepared statement handle is re-used quite some time. The system benefits from early optimisations.  In a typical PHP Web application this isn't the case. A request and therefore a database connection with its associated …

Check out this great MySQL-related post. Meta. hehehe.

Check out this excellent article by Shlomi Noach!!

Really - my life is much happier now, and as a bonus I got a free set of steak knives and even lost 20 pounds. (and MySQL!)

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