I read an article recently, about how mobile apps will probably not get the hardware boost that people are expecting.

This is partially to do with that CPU performance hitting a sort of (heat) wall and cannot improve on their speed. As Linley Gwenapp said “we’ve been falling behind Moore’s Law ever since Intel hit the power wall back in 2005”.


I myself have noticed that on a few occasions when companies decided to buy an expensive machine for their main server, it turned out to perform slower on queries than their previous soon-to-be-updated machine.

In a …

Percona Server’s “crash-resistant replication” feature is useful in versions 5.1 through 5.5. However, in Percona Server 5.6 it’s replaced with Oracle MySQL 5.6′s “crash safe replication” feature, which has it’s own implementation (you can read more about it here).

A MySQL slave normally stores its position in files master.info and relay-log.info which are updated by slave IO_THREAD & slave SQL_THREAD respectively. The file master.info contains connection info & replication coordinates showing how many events were fetched from the master binary log. The relay-log.info, on the other hand, represents info showing the positions where the slave applied those events. You can read more about slave status logs …

Introduction

InnoDB is a general-purpose storage engine that balances high reliability and high performance. It is a transactional storage engine and is fully ACID compliant, as would be expected from any relational database. The durability guarantee provided by InnoDB is made possible by the redo logs.

This article will provide an overview of the redo log subsystem or log subsystem of InnoDB. We will look at the following details:

• The global log system object, which provides access to important data structures and information.
• The mini-transaction (mtr), using which all redo log records are created.
• The global in-memory log buffer (or just log buffer), into which the redo logs are written to from the mini transaction buffer. This log buffer will be periodically flushed to the log file on disk. …

This is a very simple batch script for mysql backup on windows.

@echo off
 
REM "MySQL username"
SET muser="dba"
 
REM "MySQL password"
SET mpass="password"
 
REM "Source destination for mysqldump (executable)"
SET mbackup="C:\My Documents\mariadb-5.5.29-win32\bin"
 
REM "Backup destination for mysql"
SET mysqlbackup="C:\My Documents\backup\"
 
REM "Exclude database backup"
SET dbname="('information_schema','performance_schema')"
 
REM "Dump database to file"
for /f %%i in ('"%mbackup%\mysql -u%muser% -p%mpass% -e "select distinct table_schema from information_schema.tables where table_schema NOT IN %dbname%" --skip-column-name "') do (
    %mbackup%\mysqldump %%i -u%muser% -p%mpass% > %mysqlbackup%%%i.sql
)

It can be automated using scheduler in windows.

Tags: backup scriptwindowsCategory:  …

This is either too funny or too sad.

An acquaintance sent me this image from a cyber cafe or hotel in Russia. It says that my blog site is prohibited and violates Russian law, and that they’re blocking my site in accordance with the Russian Federal Law of 27.07.2006 No. 149-FZ.

All I can say is, “Wow!” I didn’t know that stuff about writing programs, web pages, and solving generic database and operating system problems was so sensitive. For that matter, I didn’t know what I post would interest any government. I half wonder whether my friend’s pulling my leg.

As I reflect on it, could it be that Oracle post on how to write an encrypted object type? or, how with proper OS credentials …

SQL tidbits are always valuable and highly searched for by newbies (as opposed to reading the SQL documentation). Sometimes we seasoned SQL developers take for granted little things like when a single- or multiple-character wildcard comparison works. It seems we know what newbies don’t. That you need a wildcard comparison operator not simply and equality comparison operator.

The question posed to me was, “Why doesn’t my wildcard comparison work?” Here’s a simplified example of their question.

SELECT 'Valid' AS "Test"
FROM    dual
WHERE  'Treat' = 'Tre_t'
OR     'Treet' = 'Tre_t';

Naturally, the answer is that the equality operator compares the strings based on their exact match (character sensitively in Oracle and character insensitively in MySQL). It needs to be rewritten by replacing the equals (=) comparison operator with the LIKE …

I registered yesterday for Oracle OpenWorld 2013, and I’ll look forward to seeing friends there. Having worked in the Oracle 12c beta for a year, I’ll be interested in the presentations. Also, hearing more about Java 7 at JavaOne. On the downside, I’m missing MySQL Connect this year.

Cloud computing offers many possibilities, and container and pluggable databases are a great solution. We’ve two new acronyms with the Oracle 12c release. A containerized database is a CDB, and a pluggable database is a PDB. I’m looking forward to seeing more about the provisioning of PDBs during the conference. If you’re new to the changes, check out CDBs and PDBs in Chapter 17 in the …

This article addresses the benefits provided from database virtualization. Before we proceed however, it is important to explain that database virtualization does NOT mean simply running a DBMS inside a virtual machine.

Database Virtualization, More Than Running a DBMS in a Virtual Machine While running a DBMS in a VM can provide advantages (and disadvantages) it is NOT database virtualization. Typical databases fuse together the data (or I/O) with the processing (CPU utilization) to operate as a single unit. Simply running that single unit in a VM does not provide the benefits detailed below. That is not database virtualization that is merely server virtualization.
An Example of the Database Virtualization Problem Say you have a database handling banking and I have $10MM in the bank (I wish). Now let’s assume that the bank is busy, so it bursts that database across 3 VM nodes in typical cloud-style.  …

This article addresses the benefits provided from database virtualization. Before we proceed however, it is important to explain that database virtualization does NOT mean simply running a DBMS inside a virtual machine.

Database Virtualization, More Than Running a DBMS in a Virtual Machine While running a DBMS in a VM can provide advantages (and disadvantages) it is NOT database virtualization. Typical databases fuse together the data (or I/O) with the processing (CPU utilization) to operate as a single unit. Simply running that single unit in a VM does not provide the benefits detailed below. That is not database virtualization that is merely server virtualization.
An Example of the Database Virtualization Problem Say you have a database handling banking and I have $10MM in the bank (I wish). Now let’s assume that the bank is busy, so it bursts that database across 3 VM nodes in typical cloud-style.  Now …

As there was a lot of complain recently about various cases with PERFORMANCE SCHEMA (PFS) overhead, I've decided to start a series of articles to help you to use PFS in the best way to analyze your workloads. This is the first part, starting with an overview of instrumentation problems generally..

First of all, instrumentation cannot be free! - when you want to trace or get some stats about your application internals you're adding a new code, and this code is increasing an overall code path, so your final binary simply cannot run on the same speed by definition!.. Of course, if your instrumentation code is poor, the overall overhead will be bigger ;-) but if you're designing it well, it'll be lower, but still not zero!..

Dynamic instrumentation brings additional cost - as soon as you're willing to add some advanced stuff within your instrumentation, it makes sense to not keep it active all of the time.. - …