I was digging through some old project code and found this script. Sometimes one finds oneself in an odd situation and needs to convert regular SQL, say from a MySQL database dump, into SQLite3 format. There’s not too much else to say, but here is a script that helps with the process. It can likely be improved but this handles the items that came up during conversion on initial runs.

#!/bin/sh
####
# NAME: convert-mysql-to-sqlite3.sh
# AUTHOR: Matt Reid
# DATE: 2011-03-22
# LICENSE: BSD
####
if [ "x$1" == "x" ]; then
   echo "Usage: $0 "
   exit 
fi 
cat $1 |
grep -v ' KEY "' |   
grep -v ' UNIQUE KEY "' |
grep -v ' PRIMARY KEY ' |
sed '/^SET/d' |          
sed 's/ unsigned / /g' | 
sed 's/ auto_increment/ primary key autoincrement/g' |
sed 's/ smallint([0-9]*) / integer /g' | 
sed 's/ tinyint([0-9]*) / integer /g' |  
sed 's/ int([0-9]*) / integer /g' |      
sed 's/

"Pinterest has learned about scaling the way most popular sites do — the architecture works until one day it doesn’t"

Advanced Weblob operations help to use Weblobs most effectively.

Weblob recap

In an earlier post I introduced Weblobs.  Weblob is a new data type that is supported by the Cloud Storage Engine for MySQL (ClouSE).  To a database developer, a WEBLOB behaves (almost) like a regular BLOB.  However, in addition to the regular BLOB functionality, Weblobs can be downloaded directly from Amazon S3 by HTTP URLs.

In MySQL, a Weblob is expressed via a pair of BLOB fields that have a special naming convention: field_name$wblob and field_name$wblob_info.  The latter field is what provides the Weblob functionality.  It can be used to retrieve the direct Amazon S3 URL for the BLOB

I got a few questions like the ones below that I’d like to address to avoid further confusion.
How exactly secure is ClouSE for MySQL, the first secure database in the cloud? Am I protected against standard application level security attacks or even accidental admin mistakes?
With the help of ClouSE I get instantaneous backup for my database on the highly durable cloud storage. But how would I protect my data in case a malicious attack or an accident did occur?

Re: security

I’ve got a comment pointing out that data encryption on the storage level doesn’t protect from SQL injections.  Of course, data encryption does not protect from SQL injections (as long as there is SQL involved, there will be a risk of a SQL

This past week I attended OSCon, the annual conference for open source’s true believers. And there was a religous fervor in the air, particularly from the point of view of someone more accustomed to Oracle conferences.

And if open source is the religion, proprietary closed-source companies are the devil. That having been said, I was surprised how virtually all large companies were demonized. Even long-time defenders of open source like IBM were ignored at best. That didn’t prevent the from coming though, with Microsoft and HP in particular with high-profile sponsorships and PR offensives that didn’t seem to have much influence with the crowd.

The companies generating buzz were the small companies built around development of their own open source products. There are a surprising number of them out

"Why the days are numbered for Hadoop as we know it"

Can OLTP database workloads use Amazon S3 as primary storage? Now they can, thanks to the Cloud Storage Engine (ClouSE), but the question is: how fast?

• ClouSE on “across the street” vs. “across the continent” cloud storage
• ClouSE vs InnoDB
• ClouSE benefits

To answer the question about performance, we decided to run db_STRESS benchmark on a MySQL database in Amazon EC2.  We compared 3 configurations:

• “Across the street storage”: ClouSE with data stored in S3 in the same region (US Standard)
• “Across

What do you think of this piece of C code?

  void foo(long v) {
    unsigned long u;
    unsigned sign;
    if (v < 0) {
      u = -v;
      sign = 1;
    } else {
      u = v;
      sign = 0;
    }
    ...

  mysql> create table t1 (a bigint) as select '-9223372036854775807.5' as a;
  mysql> select * from t1;
  +----------------------+
  | a                    |
  +----------------------+
  | -'..--).0-*(+,))+(0( | 
  +----------------------+

So can you spot what is wrong with the code? Looks pretty simple, does it

I’ve been working on a data archival project over the last couple weeks and thought it would be interesting to discuss something a bit counter-intuitive. Absolutes are never true, but when getting rid of data, it’s usually more efficient to insert the data being kept into a new table rather than deleting the old data from the existing table.

Here is our example table from the IMDB database.

mysql> show create table title\G
*************************** 1. row ***************************
       Table: title
Create Table: CREATE TABLE `title` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `title` text NOT NULL,
  `imdb_index` varchar(12) DEFAULT NULL,
  `kind_id` int(11) NOT NULL,
  `production_year` int(11) DEFAULT NULL,
  `imdb_id` int(11) DEFAULT NULL,
  `phonetic_code`

There are mistakes that drive you crazy when you try to understand what went wrong.

One of the most annoying and hard to catch was this, apparently harmless line:

tungsten-sandbox -m 5.5.24 --topology all-masters -n 2 -p 7300 -l 12300 -r 10300 –t $HOME/mm -d tsb-mm

The person reporting the error told me that the installation directory (indicated by "-t") was not taken into account.

I usually debug by examples, so I copied the line, and pasted it into one of my servers. Sure enough, the application did not take trat option into account. The installation kept happening in the default directory.

I knew that I had done a good job at making the application configurable, but I checked the code nonetheless. The only place where the default directory is mentioned is when the related variable is initialized. Throughout the code, there are no

Cloud-powered BLOB type provides ACID guarantees and fast direct access to blobs via Web URLs.

Storing unstructured data

Typically unstructured data (such as pictures, media files, documents)

a) Is either stored on the file system, unlike the related with it relational data which is stored in the database. This is well known, “convenient” practice that allows fast access to files but offers no transactional story and no unified data management (for db and filesystem)

b) Or is stored in BLOBs. This ensures transactional consistency and reduces management complexities, but is really bad for performance and scalability.

We took advantage of the cloud, and came up with an upgrade to the BLOB – a solution that combines the benefits of the two.

Weblob data type

Weblob is a new data type that is

I found time to continue my previous work on group commit for the binary log in MariaDB.

In current code, a (group) commit to InnoDB does not less than three fsync() calls:

"Dell announced a prototype low-power server with ARM processors, following a growing demand by Web companies for custom-built servers that can scale performance while reducing financial overhead on data centers"

1. Percona Toolkit
Percona Toolkit (aka Maatkit and Aspersa) is must have collection of advanced command-line tools which helps in performing tasks that are too difficult or complex to perform manually.

2. Mydumper
Mydumper is a high-performance multi-threaded backup/restore tool for MySQL. It’s up to 10x faster compared to mysqldump, can take consistent snapshots and provides File compression on-the-fly. Though it’s still under active development but is well tested/used in production on some large installations.

3. MySQL Master HA
This tool helps to maintain your Master-Slave