Testing Environments

Virtual Box

MySQL Sandbox

Backup

ZRM for MySQL

Tuning

mysqlsla

mysqltuner

mytop

Other

MySQL Workbench

sar-sql

Wildcard

myterm

• fifo-pending - the number of threads that have been selected to run via a pthread condition variable broadcast but have yet to begin running. This is incremented by threads that exit InnoDB when they schedule another thread to run and is decremented by the thread as soon as it begins to run.
• lifo-running - the number of threads that are currently running courtesy of the LIFO policy.

    lifo-running < fifo-pending

5084-flifo 186.22 342.65 570.79 707.82 718.84 665.60 574.96 590.33 611.15 612.69 637.37 
5084-original 180.95 335.37 516.97 645.86 625.14 648.88 658.71 579.59 515.26 431.97 255.04 

sysbench --test=oltp --mysql-db=test --oltp-table-size=2000000 --max-time=180 \
--max-requests=0 --mysql-table-engine=innodb --db-ps-mode=disable \
--mysql-engine-trx=yes --oltp-read-only --oltp-skip-trx --oltp-dist-type=uniform \
--oltp-range-size=1000 --num-threads=1 --seed-rng=1 run

innodb_buffer_pool_size=2000M
innodb_log_file_size=100M
innodb_flush_log_at_trx_commit=2
innodb_doublewrite=0
innodb_flush_method=O_DIRECT
innodb_thread_concurrency=16
max_connections=2000
innodb_max_dirty_pages_pct=80
table_cache=2000

innodb_thread_sleep_delay=0
innodb_concurrency_tickets=500
innodb_thread_lifo=1

innodb_buffer_pool_size=2000M
innodb_log_file_size=100M
innodb_doublewrite=0
innodb_flush_method=O_DIRECT
innodb_thread_concurrency=32
max_connections=2000
innodb_max_dirty_pages_pct=80
innodb_flush_log_at_trx_commit=2
table_cache=2000

procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu------
 r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa st
# Typical output from vmstat for InnoDB+FLIFO
40  0      0 56524420 1255528 5451320    0    0     0    81 1035 66694 81 11  8  0  0

# and from original InnoDB
53  0      0 56494980 1255616 5460592    0    0     0    95 1037 238890 58 23 19  0  0

1. Download and feed to package manager


2. Add my account to dba group


3. As root, /etc/init.d/oracle-xe configure to set passwords and ports

MySQL

Brian “Krow” Aker has something to say about Drizzle, InfiniDB, and column-oriented storage: “I have been asked a number of times ‘do you think there is a need for a column oriented database in the open source world?’ The answer has been yes!  . . .  I was very happy to see Calpont do their release of Infinidb last week.”

Vadim of the MySQL Performance Blog said, “As Calpont announced availability of InfiniDB I surely couldn’t miss a chance to compare it with previously tested databases in the same environment.” And he didn’t, as shows his post Air traffic queries in InfiniDB: early alpha. Bob Dempsey and Jim Tommaney of InfiniDB are in on the discussion.

Back to Drizzle for a moment, and Jay Pipes’ item, The Great Escape. “This week, I am working on putting together test cases which validate the Drizzle transaction log’s handling of BLOB columns.  . . .  I ran into an interesting set of problems and am wondering how to go about handling them. Perhaps the LazyWeb will have some solutions.  . . .  The problem, in short, is inconsistency in the way that the NUL character is escaped (or not escaped) in both the MySQL/Drizzle protocol and the MySQL/Drizzle client tools.”

Baron Schwartz has been catching erroneous queries, without MySQL proxy, having been inspired by Chris Calender’s post, Capturing Erroneous Queries with MySQL Proxy.

Nick Goodman promises instant relief from slow MySQL reporting queries using dynamoDB. And no gooey applicator!

Robert Hodges of the Scale-Out Blog looks at replicating from MySQL to Drizzle and beyond. “I am . . . delighted that Marcus Erikkson has published a patch to Tungsten that allows replication from MySQL to Drizzle. He’s also working on implementing Drizzle-to-Drizzle support, which will be very exciting.  . . .  This brings up a question–what about replicating from MySQL to PostgreSQL? What about other databases?”

And back to xaprb, where Baron confesses, I’m a Postgres user, as it turns out.

PostgreSQL

Bruce Momjian has published a new security talk, Securing PostgreSQL From External Attack.

Andrew Dunstan delves into recursion in Recursion, n. See recursion. “Never,” he says, “underestimate the usefulness of silly demos (this is written for a talk next week) to teach things worth knowing.”

Bernd Helmle shares a walk-through of cloning Slony nodes. “The new stable branch 2.0 of Slony-I is out for a while now. Time to blog about one of my favorite new features there, cloning an existing node without doing an initial SUBSCRIBE command.”

SQL Server

It was PASS Summit this week. On Home of the Scary DBA, Grant Fritchey covers the event with several good posts, including PASS Summit 2009 Key Note 3. (Grant is also Geek of the Week! Congratulations, Grant! I guess. Quote: “I think most DBA’s have adminhood thrust upon them. I think the ‘accidental’ DBA is the most prevalent path into becoming a DBA. I became a full time Admin by opening my mouth once too often.”)

Aaron Bertrand also has his summary Blogging from the PASS Keynote: 2009-11-03. (Grant and Aaron both have to specify which keynote they mean, because there’s more than one keynote. This, I guess, is “keynote redundancy”, but I still think PASS needs to normalize.)

Greg Low announces the launch at the PASS Summit of a new book, SQL Server MVP Deep Dives. “This is no ordinary book,” he writes. “Paul Nielsen took up Steve Ballmer’s challenge at a recent MVP summit to do something notable to give back to the community. He organised a large group of SQL Server MVPs to create a unique book and worked with Manning to get it published. The money made on the book was to go directly to a charity and the charity chosen was WarChild.”

Ben Nevarez asks, Are You Using Scalable Shared Databases? “Did you know that you can share read-only databases between several instances of SQL Server?  . . .  Scalable Shared Databases is a very interesting SQL Server feature that many of us seem to almost have forgotten about . . . ”

Here’s Roman Rehak reporting an issue with restoring 2000 backups on 2008. He writes, “Recently we’ve been experiencing a lot of headaches with SQL Server 2008 crashing while restoring a backup taken on a SQL Server 2000 production server. The crash resulted in a stack dump but SQL Server would continue running, although less stable, and sooner or later needed a reboot.”

Meanwhile, Adam Machanic reports on SQL Server 2008: lock escalation, INSERTs, and a potential bug. Adam says, “Lock escalation is a funny thing. I’ve found myself on numerous occasions waging war against its concurrency-sapping existence, and rarely have I found myself wishing that it would work more aggressively. But there is a time and place for everything, and yesterday I discovered that a major change has occurred with regard to lock escalation in SQL Server 2008.”

Oracle

Mohammed Mawla on the Pythian Blog bridges the gap with his item on running the same query against multiple SQL Server AND Oracle instances.

Surachart Opun shares his HOWTO on using DUPLICATE without a connection to target database: “ . . . that’s a 11gR2 Feature. DUPLICATE can be performed without connecting to a target database. This requires connecting to a catalog and auxiliary database.”

Here’s another HOWTO, this one from the great grandson of Husnu Sensoy: How to Install Oracle 11g Release 2 on OEL 5.4 on VirtualBox: Installing Grid Infrastructure. He begins, “In Oracle 11g Release 2 you will find that things have changed even for single instance database installation. I will try to illustrate in this series of posts how to install a single instance Oracle 11g Release 2 database to your Linux machines.”

But let’s step back a bit. Ronny Egners says, Oracle on linux – yes of course – but what linux?. “There is a discussion from December 2008 what Linux (SLES vs. Red vHat vs. Oracle Enterprise Linux) to use for running oracle on Linux by Yann Neuhaus.  . . .  After nearly one year i wanted to catch up the article and check if the pros and cons are still valid or if there changed anything.”

Chen Shapira offers The Senile DBA Guide to Troubleshooting Sudden Growth in Redo Generation, which begins, “I just troubleshooted a server where the amounts of redo generated suddenly exploded to the point of running out of disk space.  . . .  The problem was found and the storage manager pacified, I decided to save the queries I used.  . . .  It was very embarrassing to discover that I actually have 4 similar but not identical scripts . . .  Now I have 5.”

Embarrassing, Chen! But do you have guilty feelings like Martin Widlake does? He makes a guilty confession. The sin? “I use the Buffer Cache Hit Ratio.”

Last, Tyler Muth introduces Logger, A PL/SQL Logging and Debugging Utility.

That is all for now. Please let’s hear your favourite database blogs in the comments. Until next time!

Follow 451 CAOS Links live @caostheory on Twitter and Identi.ca
“Tracking the open source news wires, so you don’t have to.”

For the latest on Oracle’s acquisition of MySQL via Sun, see Everything you always wanted to know about MySQL but were afraid to ask

# Funambol acquired Zapatec, an AJAX web 2.0 frameworks vendor.

# The top ten issues facing open source users, according to Mark Radcliffe.

# Google open sourced its Closure JavaScript tools.

# Sam Ramji explained why open source still matters in the cloud.

# Likewise Software launched Enterprise Starter Packs for integration with Active Directory.

# Eucalyptus Systems updated its open source cloud computing software.

# RiverMuse hired a new CEO released Enterprise Subscription version.

# Jaspersoft joined the Open Source Software Institute.

# Hitachi joined Red Hat’s Advanced Mission-Critical Program.

# SourceForge became GeekNet, reported third quarter results.

# Mark Fidelman supplied six laws for expanding an open source business strategy into Europe.

# Eric Raymond launched ForgePlucker, for extracting project-state from forges for backup and offline analysis.

# Versant relicensed its db4o database from GPLv2 to the GPLv3.

# Hippo and Sonatype announced a distribution and technology partnership.

# Mandriva released Mandriva Linux 2010.

# Mary Jo Foley reported on Microsoft’s Orchard open source content management app.

# Zend Technologies is working with Oracle to deliver an integrated Unbreakable Linux and PHP offering.

# Subversion was submitted to become an Apache incubator project.

# Pentaho released Pentaho Analyzer and unveiled an “Agile BI” initiative.

# Red Hat CEO said open source needs champions - such as Red Hat and Google.

# eWeek reported that Microsoft has recommitted another $100K to Apache.

# Stephen O’Grady speculated on Amazon, RDS and the Future of MySQL.

RDS brings with it the promise of MySQL on a Cloud. Having been a MySQL fan for quite some time now, I was itching to get my hands on an AWS account and check out what the hype was all about. Imagine my confusion when I signed up for Amazon RDS and all the AWS Management Console showed me was the EC2 dashboard! It was time I downloaded the Getting Started Guide and went through the rigmarole of studying it.

Setting up the Command Line Interface Tools

Apparently, there is no GUI yet for RDS. The only way to go about using it is through the CLI tools. Setting up the tools, however, can be quite a pain: There are no installers per se; you have to download the archive, extract it, and set up the environment manually. Here’s how I did it on my Windows XP box:

• Prerequisites: The CLI tools are written in Java. So you need to have either JDK or JRE installed on your system to be able to run them. I had JRE 6 installed.
• The Environment: There are a couple of environment variables that need to be set, manually:
  • The JAVA_HOME variable, containing the path of the Java runtime installed on the system.
  • The AWS_RDS_HOME variable, containing the path to the folder containing the CLI tools.

C:\>set JAVA_HOME=E:\Java\jre6

C:\>set AWS_RDS_HOME=C:\Amazon RDS\CLI

• The Credential File: The archive containing the CLI tools also had a file named credential-file-path.template. I copied my AWS Access and Secret Keys into the place holders in the file, and then had to set yet another environment variable:

C:\>set AWS_CREDENTIAL_FILE=C:\Amazon RDS\CLI\credential-file-path.template

• One Last Thing: Finally, I was almost done (setting up the CLI tools, that is)! All I had to do was add the path of the CLI tools to the PATH variable:

C:\>set PATH=%PATH%;C:\Amazon RDS\CLI

Creating a Database Instance

I went on to create an Extra Large database instance, with an allocated storage of 5GB:

C:\>rds-create-db-instance --engine MySQL5.1 --master-username root --master-user-password mypass
--db-name WebyogTestData --db-instance-identifier webyogtestinstance --allocated-storage 5
--db-instance-class db.m1.xlarge –-header
DBINSTANCE  DBInstanceId        Class         Engine    Storage  Master Username
Status    Backup Retention
DBINSTANCE  webyogtestinstance  db.m1.xlarge  mysql5.1  5        root
creating  1
SECGROUP  Name     Status
SECGROUP  default  active
PARAMGRP  Group Name        Apply Status
PARAMGRP  default.mysql5.1  in-sync
C:\>

The rds-decribe-db-instances command displays all the running instances:

C:\>rds-describe-db-instances
DBINSTANCE  webyogtestinstance  2009-11-06T08:40:52.571Z  db.m1.xlarge  mysql5.1
5   root  available  webyogtestinstance.clc2ed76md1v.us-east-1.rds.amazonaws.com 3306  us-east-1d  1
SECGROUP  default  active
PARAMGRP  default.mysql5.1  in-sync
C:\>

Voila! My database is up and running in no time.

Setting up SQLyog/MONyog to Connect to Amazon RDS

Here’s the best part about Amazon RDS: It has native MySQL 5.1 support. (Well, at this time, it supports  no other RDBMS, but may be  it will in the future.) This means that I can use my favorite MySQL GUI tool to connect to the Amazon RDS database instance. Or at least that’s what Amazon claims.

I filled in the master user name and password that I had used to create the DB instance. For the host address, I used webyogtestinstance.clc2ed76md1v.us-east-1.rds.amazonaws.com (I noticed it in the output of the rds-describe-db-instances command).

Apprehensively, I clicked on the Test Connection button and without a hitch it connected successfully. Notice that SQLyog reports as having connected to MySQL 5.1.38-log.

Setting up MONyog was as simple.

MONyog displaying the InnoDB Cache stats

In Conclusion

RDS is but a MySQL 5.1 instance running on an EC2 platform, bringing with it all the advantages of EC2. You can scale your server to use up to 68GB of memory, 26 ECUs, and 1TB of persistent storage. On the flip-side, Amazon RDS does not support replication yet.

Periodically, the Amazon RDS system performs some maintenance of the database instance. This ensures that your server is running smoothly. This also translates into a 4-hour down time period on a weekly basis.

There is a pattern emerging here, if you look close enough. Back in 2008, at about the same time, when it became clear that Microsoft would announce a Windows-based Cloud, Amazon jumped in and announced support for Windows-based EC2 instances. And Amazon has managed to do it again with RDS. Microsoft, it seems, drives Amazon harder than users do.

For us at Webyog this is an exciting development. We believe that our products (SQLyog and MONyog) are very well ‘fit for the Cloud’.  Much more fit than the console-based tools that most advanced users still seem to use.  We will now start checking our programs in detail with this. Till now we’ve found no issues.

Want to Know More?

Read more about Amazon RDS froom their website.

Amazon RDS Functionality.

Pricing plans for Amazon RDS.

Sign up for Amazon RDS.

CREATE TABLE pbms.pbms_backup (
id INT NOT NULL AUTO_INCREMENT,
Database_Name VARCHAR(64) NOT NULL,
Started TIMESTAMP,
Completed TIMESTAMP,
IsRunning BOOL,
IsDump BOOL,
Location VARCHAR(1024),
Cloud_Ref INT,
Cloud_backup_no INT,
PRIMARY KEY (id)
)

• MySQLDump: To backup the repository using 'mysqldump' you simply dump the database's 'pbms_dump' table. This table is a one column table of type 'long blob'. Any select from this table is assumed to be a repository backup and any insert into the table is assumed to be a repository recovery. Selecting the data from the 'pbms_dump' table results in a new record being added to the 'pbms.pbms_backup' table. To recover the repository the dumped data is inserted back into the 'pbms_dump' table. During the recovery it is important to set the pbms variable "Restoring-Dump" in the database's 'pbms_variable' table to "TRUE". This tells the PBMS engine that the database is being recovered and that insertion of BLOB references should not increment the BLOB reference count.
• Engine level backup: To perform an engine level backup all you do is insert a record into the 'pbms.pbms_backup' table providing the name of the database to be backed up and the location into which the backup should be placed. This starts an asynchronous backup operation. To recover the repository from the backup all you do is drag and drop the backup into your recovered database.

• database_id is the id of the database as provided by the PBMS engine.
• backup_no is the backup number of the BLOB. For BLOBs that are not backup copies this number is always zero. The backup number is just a sequence counter that ensures that the backup BLOBs have a unique name. All backup BLOBs from the same backup will have the same backup number. This backup number is stored in the 'Cloud_backup_no' column of the 'pbms.pbms_backup' table.
• cloud_ref is the reference into the 'pbms.pbms_cloud' table that refers to the S3 server and bucket in which the BLOB is stored.
• time_stamp is the time in seconds at which the BLOB was created.
• sequence_count is just a counter to ensure that no 2 BLOBs get the same name.

Let me explain the reason of choosing these engines. After initial three posts I am often asked "What is baseline ? Can we compare results with standard MySQL engines ?". So there come MyISAM to consider it as base point to see how column-oriented-analytic engines are better here.

However, take into account, that for MyISAM we need to choose proper indexes to execute queries effectively, and there is pain coming with indexes: - load of data is getting slower; - to design proper indexes is additional research, especially when MySQL optimizer is not smart in picking best one.

The really nice thing about MonetDB, InfoBright, InfiniDB is that they do not need indexes, so you may not worry about maintaining them and picking best one. I am not sure about LucidDB, I was told indexes are needed, but creating new index was really fast even on full database, so I guess, it's not B-Tree indexes. So this my reflexion on indexes turned me onto TokuDB direction.

What is so special about TokuDB ? There two things: indexes have special structure and are "cheap", by "cheap" I mean the maintenance cost is constant and independent on datasize. With regular B-Tree indexes cost grows exponentially on datasize (Bradley Kuszmaul from Tokutek will correct me if I am wrong in this statement). Another point with TokuDB, it uses compression, so I expect less size of loaded data and less IO operations during query execution.

So what indexes we need for queries. To recall you details, the schema is available in this post
http://www.mysqlperformanceblog.com/2009/10/02/analyzing-air-traffic-performance-with-infobright-and-monetdb/, and
queries I posted on sheet "Queries" in my summary Spreadsheet.

With Bradley's help we chose next indexes:

And I measured load time for both MyISAM and TokuDB in empty table with created indexes.

Load time for MyISAM: 16608 sec
For TokuDB: 19131 sec

Datasize (including indexes)

MyISAM: 36.7GB
TokuDB: 6.7GB

I am a bit surprised that TokuDB is slower loading data, but my guess it is related to compression, and I expect with bigger amount of data TokuDB will be faster MyISAM.

Now to queries. Bradley pointed me that query Q5 SELECT t.carrier, c, c2, c*1000/c2 as c3 FROM (SELECT carrier,
count(*) AS c FROM ontime WHERE DepDelay>10 AND Year=2007 GROUP BY
carrier) t JOIN (SELECT carrier, count(*) AS c2 FROM ontime WHERE
Year=2007 GROUP BY carrier) t2 ON (t.Carrier=t2.Carrier) ORDER BY c3 can be rewritten as
SELECT carrier,totalflights,ndelayed,ndelayed*1000/totalflights as c3 FROM (SELECT carrier,count(*) as totalflights,sum(if(depdelay>10,1,0)) as ndelayed from ontime where year=2007 group by carrier) t order by c3 desc; ( I name it as Query Q5i)

The summary table with queries execution time (in sec, less is better):

For reference I used 5.1.36-Tokutek-2.1.0 for both MyISAM and TokuDB tests.

And if you are interested to compare MyISAM with previous engines:

The all results are available in summary Spreadsheet

I especially do not put TokuDB in the same table with analytic oriented databases, to highlight TokuDB is OLTP engine for general purposes.
As you see it is doing better than MyISAM in all queries.

Entry posted by Vadim | One comment

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GoodData

Mark Logic

Kognitio

Infobright

The details:
San Francisco
4th December
9:30AM - 5PM

Spaces are limited, so to give everyone a fair chance we're delaying registration to open at noon tomorrow (Friday) Pacific Time. It's strictly first in first served, so be quick!  The registration link is here.

Entry posted by Morgan Tocker | One comment

Add to: | | | |

• Step 1: The BLOB metadata is sent to the PBMS engine.
• Step 2: A repository record is created containing the BLOB metadata.
• Step 3: A reply is sent back to the client containing the BLOB reference which is passed back up to the client application to be inserted into the user's table in place of the BLOB. An S3 authorization signature is also returned to the client. The authorization signature is generated by the PBMS engine using the Public/Private keys for the S3 server to sign the BLOB upload request.
  
• Step 4: The PBMS client library uses the authorization signature to upload the BLOB to the S3 server.

• Step 1: A BLOB request containing a PBMS BLOB reference is sent to the PBMS engine’s HTTP server.
• Step 2: The BLOB’s repository record is read from local storage.
• Step 3: An HTTP redirect reply is sent back to the client redirecting the request to the BLOB stored in the cloud. The metadata associated with the BLOB is returned to the client in the reply’s HTTP headers. The redirect URL is an authenticated query string that gives the client time limited access to the BLOB data. Use of an authenticated query string allows the data in the cloud to have access protection without requiring the client applications to know the private key normally required to get access.
• Step 4: The redirect is followed to the cloud and the BLOB data is retrieved.

• Copy the BLOB data from the amazon server to the Sun server.
• Update the pbms_cloud table as: UPDATE pbms.pbms_cloud set server = "S3.sunaws.com", Bucket = "B3" PublicKey = "zft123", PrivateKey = "abc123" where id = 17;
• Delete the BLOBs on the amazon server.

Results

Pages read 7444152, created 94756, written 2758813
Read ahead: 255016 random, 428633 sequential
Sync reads: 6730101 requests, 0 old, 16384.30 bytes/r, svc: 106827.43 secs, 15.87 msecs/r, 807.76 max msecs, wait: 106827.57 secs 15.87 msecs/r, 807.76 max msecs
Async reads: 374094 requests, 0 old, 31269.07 bytes/r, svc: 3037.55 secs, 8.12 msecs/r, 473.97 max msecs, wait: 24448.33 secs 65.35 msecs/r, 473.97 max msecs

Pages read 7025361, created 89550, written 2778099
Read ahead: 0 random, 0 sequential
Sync reads: 6994645 requests, 0 old, 16384.29 bytes/r, svc: 90021.08 secs, 12.87 msecs/r, 1289.22 max msecs, wait: 90021.21 secs 12.87 msecs/r, 1289.22 max msecs
Async reads: 20932 requests, 0 old, 24078.19 bytes/r, svc: 267.37 secs, 12.77 msecs/r, 326.25 max msecs, wait: 347.28 secs 16.59 msecs/r, 326.25 max msecs

Even though there are several distributed alternatives available for some years now (with Bazaar, git and Mercurial being the most prominent representatives here), many large and popular Open Source projects still use centralized systems like Subversion or even CVS to maintain their source code. While Subversion has eased some of the pains of CVS (e.g. better remote access, renaming/moving of files and directories, easy branching), the centralized approach by itself poses some disadvantages compared to distributed systems. So what are these? Let me give you a few examples of the limitations that a centralized system like Subversion has and how these affect the possible workflows and development practices.

KickFire

Greenplum

Groovy

Aster Data

To me, Aster is more aggressively driving their platform into green fields trying to leverage their technology to find new customers and new markets.  Greenplum on the other hand is more ‘steady as she goes’, focusing on a more traditional and conservative enterprise data warehousing market (while still innovating ahead of the general purpose behemoth's).  The risks are on both sides.  When trying to define a new market you risk not finding one or finding one that is too small or “niche” to support your business.  With the conservative approach you risk being lumped in with everyone else, and in data warehousing ‘everyone else’ is now quite a long list. 

>> part 2 

With many thanks to Vadim at Percona for his analysis of different capabilities of different columnar dbms. Definitely good information, and well documented.  Queries and results available at:

http://www.mysqlperformanceblog.com/2009/11/02/air-traffic-queries-in-infinidb-early-alpha/

Of course InfiniDB, does offer multi-threaded processing for all offerings and distributed prRead More...
PlanetMySQL Voting: Vote UP / Vote DOWN]]> Thu, 05 Nov 2009 19:55:24 +0000 Jim Tommaney scalability Performance multi-threaded http://www.mysqlperformanceblog.com/?p=1616 http://www.mysqlperformanceblog.com/2009/11/05/innodb-look-after-fragmentation/ One problem made me puzzled for couple hours, but it was really interesting to figure out what's going on. So let me introduce problem at first. The table is PLAIN TEXT CODE: CREATE TABLE `c` (   `tracker_id` int(10) unsigned NOT NULL,   `username` char(20) character set latin1 collate latin1_bin NOT NULL,   `time_id` date NOT NULL,   `block_id` int(10) unsigned default NULL,   PRIMARY KEY  (`tracker_id`,`username`,`time_id`),   KEY `block_id` (`block_id`) ) ENGINE=InnoDB Table has 11864696 rows and takes Data_length: 698,351,616 bytes on disk The problem is that after restoring table from mysqldump, the query that scans data by primary key was slow. How slow ? Let me show. The query in question is (Q1): SELECT count(distinct username) FROM tracker where TIME_ID >= '2009-07-20 00:00:00' AND TIME_ID = '2009-07-20 00:00:00' AND TIME_ID One problem made me puzzled for couple hours, but it was really interesting to figure out what's going on.

So let me introduce problem at first. The table is

Table has 11864696 rows and takes Data_length: 698,351,616 bytes on disk

The problem is that after restoring table from mysqldump, the query that scans data by primary key was slow. How slow ? Let me show.

The query in question is (Q1):

SELECT count(distinct username) FROM tracker where TIME_ID >= '2009-07-20 00:00:00' AND TIME_ID <= '2009-10-21 00:00:00' AND (tracker_id=437)


On cold buffer_pool, it took:

However the query (again on cold buffer_pool) (Q2)

SELECT count(distinct username) FROM tracker where TIME_ID >= '2009-07-20 00:00:00' AND TIME_ID <= '2009-10-21 00:00:00'


Difference is impressive. 4 min 13.61 sec vs 18.81 sec

If you want EXPLAIN plain, here it is:

For Q1:

For Q2:

Query Q1 is executed using Primary Key, and Query Q2 is using block_id key.

To get more details I ran both queries with our extended stats in slow.log (available in 5.0-percona releases)

So for query Q1:

And for query Q2:

As you see for Q1 IO read took 236.149003 sec vs 0.165124 for Q2. But Q1 is scan by primary key, which supposed to be
sequential!

Let's see on another statistic, which available in innodb_check_fragmentation patch:

for Q1:

and for Q2:

So you see for Q1 it was not sequential scan, even it is primary key, but it is sequential for Q2.

So what's the answer ? It's fragmentation of primary key (and whole data table, as InnoDB data == primary key). But how it could happen with
primary key after mysqldump ? The answer here if we look on

EXPLAIN SELECT * FROM tracker;

We see that dump is taken in key "block_id" order, not in primary key order. And later when we load this table, INSERTS into primary key happens in random order, and that gives us the fragmentation we see here.

How to fix it in our case. It's easy: ALTER TABLE tracker ENGINE=InnoDB, it will force InnoDB to rebuild table in primary key order.

After that Q1:

You see that time returned to appropriate 17.72 sec.

You may ask what happens now with Q2 ? yes, it's getting slow now, as we made key "block_id" inserted not in order.

As for mysqldump you may use --order-by-primary options to force dump in primary key order.

So notes to highlight:

• InnoDB fragmentation may hurt your query significantly, especially when data is not in buffer_pool and execution goes to read from disk
• Fragmentation by secondary key is much more likely than by primary key, and you cannot really control it (tough it is possible in XtraDB / InnoDB-plugin with FAST INDEX creation) so be careful with queries scan many records by secondary key
• To check if you query affected by fragmentation you can use Innodb_scan_pages_contiguous ; Innodb_scan_pages_jumpy statistics in 5.0-percona releases (coming to 5.1-XtraDB soon)

Entry posted by Vadim | 3 comments

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1. myterm> SELECT engine, count(*) AS count FROM information_schema.tables GROUP BY 1 ORDER BY 2 DESC | chart pie | browser

What's that?

Some examples

1. myterm> SHOW PROCESSLIST
2. +------+------+-----------------+------+---------+------+-------+------------------+
3. | Id | User | Host | db | Command | Time | State | Info |
4. +------+------+-----------------+------+---------+------+-------+------------------+
5. | 4789 | root | 127.0.0.1:59047 | test | Query | 0 | | SHOW PROCESSLIST |
6. +------+------+-----------------+------+---------+------+-------+------------------+
7. 1 row in set (0.000 sec)

1. myterm> SHOW PROCESSLIST | cols 2-3
2. +------+-----------------+
3. | User | Host |
4. +------+-----------------+
5. | root | 127.0.0.1:59047 |
6. +------+-----------------+
7. 1 row in set (0.000 sec)

1. myterm> SHOW DATABASES | grep info
2. +--------------------+
3. | Database |
4. +--------------------+
5. | information_schema |
6. +--------------------+
7. 1 row in set (0.001 sec)

1. myterm> SELECT CONCAT(table_schema, '.', table_name) AS 'Table', data_length + index_length AS Bytes FROM information_schema.tables ORDER BY 2 DESC | other 7 | chart hbar

1. myterm> SHOW PROCESSLIST|insertify|tsv -N -E
2. CREATE TABLE 'some_table' (
3. 'Id' bigint(11) NOT NULL DEFAULT '',
4. 'User' varchar(16) NOT NULL DEFAULT '',
5. 'Host' varchar(64) NOT NULL DEFAULT '',
6. 'db' varchar(64) DEFAULT NULL,
7. 'Command' varchar(16) NOT NULL DEFAULT '',
8. 'Time' int(7) UNSIGNED NOT NULL DEFAULT '',
9. 'State' varchar(30) DEFAULT NULL,
10. 'Info' varchar(100) DEFAULT NULL
11. ) ENGINE=InnoDB;
12. INSERT INTO some_table (Id, User, Host, db, Command, Time, State, Info) VALUES ('4789', 'root', '127.0.0.1:59047', 'test', 'Query', '0', NULL, 'SHOW PROCESSLIST');
13. 2 rows in set (0.000 sec)

1. myterm> plugins list
2. 15 plugins loaded:
4. Filters:
5. cols Filters columns and column ranges.
6. grep Filters lines containing the specified text in any column.
7. insertify Creates insert statements based on a result set.
8. other Reduces a result to max N rows, collapsing any extra rows to a row titled Other at the end.
10. Presenters:
11. chart Renders a chart using php Libchart.
12. html Formats the data to a html table.
13. md5 Calculates an md5 checksum of all rows and column values.
14. plain Formats the data to the default plain text table grid.
15. tsv Formats the data to tab-separated-values plain text.
16. vert Presents the data in a vertical plain-text fashion, similar to mysql \G output format.
17. vhtml Formats the data to a record by record, vertical html table.
19. Dests:
20. browser Sends the output to the browser.
21. file Sends output to a file with the given filename.
22. mailto Sends output to the registered email application using a mailto: link
23. std Sends output to standard out.

Current status

Download

1. bzr branch lp:myterm

Contribute

I had some tweets about the situation and briefly chatted with Florian Müller whom everybody should know from 2004's anti software patent EU campaign and who is acting as a formal advisor in the current EU observation regarding the deal. I believe in Open Source being "free as in freedom". In the last months I haven't heard anything from Oracle itself regarding its future plans for MySQL. And when I read this article ("Oracle plans aggressive fight [...]") from PC World magazine I'm not sure if it would be quite a good thing that Oracle will own MySQL in the future. Does Oracle have experience in growing and maintaining an Open Source community accepting the dual-license nature of the software, and will it invest into MySQL?

By splitting off MySQL (i.e. selling it to another business) it has to be assured that there's a company behind MySQL that thrives the further adoption of MySQL especially in the Enterprise Business. That's why in the past decade MySQL grew from a small database to a great database server which suits a lot of enterprise needs for the web. I don't want that industry fall back - the future is the web and the database for the web is MySQL.

I'm pretty sure that EU commisioner Kroes will do the right decision by end of January 2010.

This replaces MySQL Cluster 7.0.9.

You can either wait for the binaries to be released or if you’re in a rush then you can find instructions on building the binaries for yourself in the earlier article: “MySQL Cluster 7.0.7 source released“.

A description of all of the changes (fixes) that have gone into MySQL Cluster 7.0.9a (compared to 7.0.8a) can be found in the MySQL Cluster MySQL Cluster 7.0.9a Change Log.

This replaces MySQL Cluster 7.3.28 which has been withdrawn.

You can either wait for the binaries to be released or if you’re in a rush then you can find instructions on building the binaries for yourself in the earlier article: “MySQL Cluster 7.0.7 source released“.

A description of all of the changes (fixes) that have gone into MySQL Cluster 6.3.28a (compared to 6.3.27) can be found in the MySQL Cluster MySQL Cluster 6.3.28a Change Log.

I always thought Dreamhost was a little skiddish, and my email box finds approximately one email per day with a failure, but i figured they were small, single request failures. Nope. The independent measuring of the uptime of this blog is a CRUDDY, CRAPPY, 97.6%.

That’s pathetic! My blog is nothing special, an out of the box Wordpress installation backed by their MySQL. I haven’t done any of my own installations, customizations (excepting a theme) and yet my blog uptime is awful. I’ve liked the dreamhost panel; it gives the “technical but uninterested in actually administering their own server” user a lot of power and I’d be willing to tolerate a little downtime (truthfully, anything above 99.5% is OK with me). But 97% uptime? Shyeah… Time to start looking.

Anyone have any suggestions for good Wordpress / PHP / MySQL hosts? WIlling to pay top dollar and I’ll bring with me registrations for about 25 domains.

What are the requirements? Having a server with HTTP access and no hassles with low traffic limits. At this stage you’ll need about 5GB disk space, and you’ll use rsync to sync from the master servers (we’ll provide you with a script to help with that). Thanks!

With the new releases the traffic is up (not surprising) and while our existing mirrors appear to be doing ok so far, it’ll be good to have more available before we run into capacity or speed problems. We also haven’t yet split for geographic location, that too becomes a possibility with more mirrors.

Now for practicals. If I look on Launchpad, the 5.1 branch is the only active one (next to 5.0 fixes, of course). 5.4 was last updated 15 weeks ago. There is no 5.2 on there that I can find. Wasn’t looking for it really, just happened to notice its absence while I was trying to find 5.5. And the reason for that was that Miguel closed a bug I was following, noting it was no longer reproducible in 5.5. He pastes some code that reports mysql as 5.5, so it’s not a typo.

So, in addition to the above list of abandonment (5.4, 6.0), we have 5.2 which I’m told should exist but doesn’t at Launchpad, and 5.5 which appears to exist and is news to me yet doesn’t appear to be out there either. Are you confused? I am.

The particular bug was found during a training session and occurs on Windows. Now the bug is closed, but we can’t see code and have no indication when it or binaries will be available. So what do I tell a user asking about the bug and its apparent fix? (I have to say apparent because Miguel’s response indicate that it’s merely not reproducible on the later version, there’s no specific fix)

Updates

• Vladislav Vainroub notes there’s a mysql-next-mr branch on launchpad which is in fact version 5.5 inside. It appears to be mirrored, last sync 5 minutes ago but last changeset 39 hours ago. So this seems like a publishing branch, not a development branch (otherwise we’d see more activity).
• Paul DuBois tells that the mysql-server trunk on launchpad is now 5.5. Last activity is from a week ago, so I presume that like the abovementioned mysql-next-mr branch it’s synced and not actually from a live development branch. Pity.

• 4.5% as measured by iostat w/s
• 13% as measured by iostat wsec/s
• 18% as measured by Innodb pages written.

• 2% as measured by iostat w/s
• 18% as measured by iostat wsec/s
• 26% as measured by Innodb pages written.

I ran into an issue with it on this server that was running the MySQL 5.0.77-percona-highperf-b13-log x86_64 build. The error was:
./tuning-primer.sh.1: line 517: 5.000000: syntax error in expression (error token is ".000000")

There were three options to fix this issue

1. Dive into the code and modify it cowboy style
2. Use our typical monitoring against the client’s wishes
3. Contact the developer to get a fix

I hopped on IRC.freenode.net to the #mysql channel and found Matthew online. Long story short he narrowed it down to the version of MySQL being from Percona that was changing the format of the variable in question vs the typical MySQL variable type. After discussing the matter he released a new build to address this change and I was on my way to generating reports again.That is quality support that you won’t see from the likes of Microsoft or Apple or any big closed-source player.

If there’s on thing to take away from this story it’s the Open Source Software will ALWAYS be better than closed source because of the hands on attitude and direct contact you can get with the developers or, at the minimum, with the large user community that is willing and able to help troubleshoot. Why are people able to help? Because the code is open and free – and people like free software that they can improve and fix themselves – and those people like to help others because we’ve all needed help at some point or another, no matter how much of an expert you are.

If there are two things to take away it’s to remember that IRC is a wealth of useful information and support for Open Source applications. You can find me on the #mysql, ##php, #perl, #extjs, and #codeigniter channels under various usernames – or idling in the #kontrollbase channel for supporting my own application.

Closed source apps are the old way to do business, the rotting steel skeletons from the industrial age of computing… Open Source is the brainy kid down the street that doesn’t want to rip you off for something that some nameless big corporation designed overseas for pennies on the dollar just to turn a profit and sell you something with crappy support and non-auditable code. Long live OSS!

I'm looking for a usable C++ IDE for Linux and I'm wondering if you've seen one. Before you start giving the normal suggestions (Ecliipse, NetBeans, just-use-vi) let start off by saying that I've tried Eclipse, Netbeans and Code::Blocks and KDevelop several times, and that I normally hack in some combination of vi and emacs. (yes yes, I know I'm supposed to religiously pick one and be rude to the other... consider me a postmodern hacker)

For it to be usable by me, it must be able to:

1. Handle the fact that my build is run with autoconf/automake.
2. Properly rename a method and have that show up throughout the codebase.
3. Properly encapsulate a variable with getter/setting methods.
4. Correctly answer the question "where is this method being used"
5. Run without consuming all of my RAM and CPU resources.
6. Quickly and easily open a new project/branch (I have 93 different branches of Drizzle in my source dir right now. Going through a 10 step process to open any given branch in the IDE== FAIL)

Bonus points given for:

1. Allowing me to deal with one or more bzr branches in a sane manner
2. Supporting an option like emacs where the tab key NEVER inserts a tab character and instead ALWAYS indents the line its on.
3. Figuring out by the existence of a configure.ac file that perhaps a Makefile will appear if it runs "autoreconf -f -i; ./configure"

If you think you have the answer, try this as a test:

• bzr branch lp:drizzle
• Open the drizzle directory as a "project"
• Build
• Find some method on the Session object in drizzled/session.h.  Rename it using the IDE. Build again.
• Find the method errmsg_printf in drizzled/errmsg_print.h. Find out every place that uses it. See if that matches what grep -r '\berrmsg_printf\b' would tell you.

Anybody? If you have an IDE and it can actually deal with my daily Drizzle development, I will happily blog both that it can and how to get started.

With InfiniDB, you have some new SQL diagnostic and tracing tools that you can use to get more performance data from SQL statements that don’t seem to be running well.  Let me give yoRead More...
PlanetMySQL Voting: Vote UP / Vote DOWN]]> Wed, 04 Nov 2009 17:14:06 +0000 Robin Schumacher http://jpipes.com/index.php?/archives/309-guid.html http://jpipes.com/index.php?/archives/309-The-Great-Escape.html This week, I am working on putting together test cases which validate the Drizzle transaction log's handling of BLOB columns. I ran into an interesting set of problems and am wondering how to go about handling them. Perhaps the LazyWeb will have some solutions. The problem, in short, is inconsistency in the way that the NUL character is escaped (or not escaped) in both the MySQL/Drizzle protocol and the MySQL/Drizzle client tools. And, by client tools, I mean both everyone's favourite little mysql command-line client, but also the mysqltest client, which provides infrastructure and runtime services for the MySQL and Drizzle test suites. Even within the server and client protocol, there appears to be some inconsistency in how and when things are escaped. Take a look at this interesting output from the drizzle client program (FYI, output is identical for mysql client, I checked...) drizzle> select 'test\0me'; +---------+ | test | +---------+ | test me | +---------+ 1 row in set (0 sec) You'll notice that in the first SELECT statement, the column header is cut off — i.e. the column header is not escaping the \0 NUL character in the string 'test\0me'. However, the result data does not truncate the string but replaces the NUL character with a space character. So, I came to the conclusion that the drizzle client does not escape column headers but does do some sort of escaping for the result data. Given this conclusion, you will understand my raised eyebrow when the following SELECT statement was displayed: drizzle> select 'test\0me' = 'test me'; +------------------------+ | 'test\0me' = 'test me' | +------------------------+ | 0 | +------------------------+ 1 row in set (0 sec) Hmmm...so maybe column headers are being escaped by the MySQL/Drizzle client? Clearly, the NUL character was escaped as the characters '\\' followed by the character '0' in the column header above. Indeed, quite puzzling. OK, so the above anomaly needs to be investigated. However, a similar issue exists for the mysqltest/drizzletest client program. To see the problem, check the following out. I create a simple test case with the following in it: --disable_warnings DROP TABLE IF EXISTS t1; --enable_warnings SELECT 'test\0me'; CREATE TABLE t1 (fld BLOB NULL); INSERT INTO t1 VALUES ('test\0me'); SELECT COUNT(*) FROM t1; DROP TABLE t1; Now, what you would expect to see for the output of the above — at least if you expect results similar to the MySQL/Drizzle client output — is the following: DROP TABLE IF EXISTS t1; SELECT 'test\0me'; test test me CREATE TABLE t1 (fld BLOB NULL); INSERT INTO t1 VALUES ('test\0me'); SELECT COUNT(*) FROM t1; COUNT(*) 1 DROP TABLE t1; That is what you would expect to see in the output of course... Here is what you actually get in the output: DROP TABLE IF EXISTS t1; SELECT 'test\0me'; test test So, the mysqltest/drizzletest client apparently does not escape the NUL character for the result data at all. It looks like it does do some escaping/replacing for the NUL character in the column header, though, otherwise the second "test" line would not appear. This leads to the result file being essentially truncated as soon as a NUL character is included in any output to the mysqltest/drizzletest client. This essentially makes the mysqltest/drizzletest client useless for testing and validating BLOB data. Possible Solutions? I think the cleanest solution would be to create a shared library of code that would be responsible for uniformly and consistently escaping data, and then linking the various clients (and server) with this library and removing all of the various escaping functions currently in the server. This would, of course, take some time, but would be the most future proof solution. Anyone else have ideas on solving the problem of being able to test and validate binary data via the test suite? Cheers! This week, I am working on putting together test cases which validate the Drizzle transaction log's handling of BLOB columns.

I ran into an interesting set of problems and am wondering how to go about handling them. Perhaps the LazyWeb will have some solutions.

The problem, in short, is inconsistency in the way that the NUL character is escaped (or not escaped) in both the MySQL/Drizzle protocol and the MySQL/Drizzle client tools. And, by client tools, I mean both everyone's favourite little mysql command-line client, but also the mysqltest client, which provides infrastructure and runtime services for the MySQL and Drizzle test suites.

Even within the server and client protocol, there appears to be some inconsistency in how and when things are escaped. Take a look at this interesting output from the drizzle client program (FYI, output is identical for mysql client, I checked...)

drizzle> select 'test\0me';
+---------+
| test    |
+---------+
| test me | 
+---------+
1 row in set (0 sec)

You'll notice that in the first SELECT statement, the column header is cut off — i.e. the column header is not escaping the \0 NUL character in the string 'test\0me'. However, the result data does not truncate the string but replaces the NUL character with a space character. So, I came to the conclusion that the drizzle client does not escape column headers but does do some sort of escaping for the result data. Given this conclusion, you will understand my raised eyebrow when the following SELECT statement was displayed:

drizzle> select 'test\0me' = 'test me';
+------------------------+
| 'test\0me' = 'test me' |
+------------------------+
|                      0 | 
+------------------------+
1 row in set (0 sec)

Hmmm...so maybe column headers are being escaped by the MySQL/Drizzle client? Clearly, the NUL character was escaped as the characters '\\' followed by the character '0' in the column header above. Indeed, quite puzzling.

OK, so the above anomaly needs to be investigated. However, a similar issue exists for the mysqltest/drizzletest client program. To see the problem, check the following out. I create a simple test case with the following in it:

--disable_warnings
DROP TABLE IF EXISTS t1;
--enable_warnings

SELECT 'test\0me';

CREATE TABLE t1 (fld BLOB NULL);
INSERT INTO t1 VALUES ('test\0me');
SELECT COUNT(*) FROM t1;
DROP TABLE t1;

Now, what you would expect to see for the output of the above — at least if you expect results similar to the MySQL/Drizzle client output — is the following:

DROP TABLE IF EXISTS t1;
SELECT 'test\0me';
test
test me
CREATE TABLE t1 (fld BLOB NULL);
INSERT INTO t1 VALUES ('test\0me');
SELECT COUNT(*) FROM t1;
COUNT(*)
1
DROP TABLE t1;

That is what you would expect to see in the output of course... Here is what you actually get in the output:

DROP TABLE IF EXISTS t1;
SELECT 'test\0me';
test
test

So, the mysqltest/drizzletest client apparently does not escape the NUL character for the result data at all. It looks like it does do some escaping/replacing for the NUL character in the column header, though, otherwise the second "test" line would not appear. This leads to the result file being essentially truncated as soon as a NUL character is included in any output to the mysqltest/drizzletest client. This essentially makes the mysqltest/drizzletest client useless for testing and validating BLOB data.

Possible Solutions?

I think the cleanest solution would be to create a shared library of code that would be responsible for uniformly and consistently escaping data, and then linking the various clients (and server) with this library and removing all of the various escaping functions currently in the server. This would, of course, take some time, but would be the most future proof solution. Anyone else have ideas on solving the problem of being able to test and validate binary data via the test suite? Cheers!

Come spend your morning/afternoon break with me and learn a few new tricks for making your applications fly. The information to sign up is at https://www.mysql.com/news-and-events/web-seminars/display-460.html. Hope to see you there!

1. ChipHacker -- collaborative FAQ site for electronics hacking. Based on the same StackExchange software as RedMonk's FOSS FAQ for open source software.
2. Democracy Live -- BBC launch searchable coverage of parliamentary discussion, using speech-to-text. One aspect we're particularly proud of is that we've managed to deliver good results for speech-to-text in Welsh, which, we're told, is unique. I think of this as the start of a They Work For You for video coverage. I'd love to be able to scale this to local government coverage, which is disappearing as local newspapers turn into delivery mechanisms for real estate advertisements.
3. InfiniDB: Open Source Column Database -- hooks into MySQL, uses MySQL for SQL parsing, security, etc. The commercial enterprise version has multi-server support (parallel scale-out). (via Brian Aker)
4. Massive Online Analysis -- MOA is a framework for data stream mining. Includes tools for evaluation and a collection of machine learning algorithms. Related to the WEKA project, also written in Java, while scaling to more demanding problems. . (via joshua on Delicious)

That’s Great Nick. But how do I do keep my data up to date?

We’ve got data in our Airline Performance dataset through 31-DEC-2007. I loaded 1 year, all of 2007, for the previous example. What happens when the FAA publishes their 2008 January results, and we’ve loaded the new months worth of data into MySQL?

MySQL:

select count(*) from otp.ontime; 8061223
select count(*) from ontime where FlightDate > ‘2007-12-31′; 605765
select count(*) from ontime where FlightDate <= ‘2007-12-31′; 7455458

DynamoDB:

select count(*) from FASTER.”ontime”; 7455458

So, we’ve added approximately 600k new records to our source system that we don’t have in our reporting system. How do we incrementally insert these records and get just the 600k new rows into our DynamoDB reporting instance?

Easy Easy Easy.

We’ve already done all the work, all we have to do is simply get records we haven’t processed yet! Should take just a few minutes to get our current table “up to date” with the one over in MySQL.

DynamoDB:

select max(”FlightDate”) from FASTER.”ontime”; 2007-12-31
insert into FASTER.”ontime” select * from MYSQL_SOURCE.”ontime” where “FlightDate” > DATE ‘2007-12-31′; 605765

In other words, let’s select from MySQL any records whose date is beyond what we have currently (2007-12-31).

select count(*) from FASTER.”ontime”; 8061223
select count(*) from FASTER.”ontime” where “FlightDate” > DATE ‘2007-12-31′; 605765

MySQL:
While the DynamoDB INSERT statement was running, the following SQL was being run on MySQL.

show processlist shows a SQL session with the following SQL:
SELECT * FROM `ontime` WHERE `FlightDate` > DATE ‘2007-12-31′;

A single SQL statement (insert into select * from table where date > last time) has you up to date for reporting! Long term we may look to work with Tungsten to be able to keep our data up to date using replication bin log records but for now, this simple pull based approach.

mysql> SHOW ENGINE INNODB STATUS\G
          _______  _______
|\     /|(  ____ \(  ____ \
| )   ( || (    \/| (    \/
| |   | || (_____ | (__
| |   | |(_____  )|  __)
| |   | |      ) || (
| (___) |/\____) || (____/\
(_______)\_______)(_______/

 _______  _______  _______ _________ _______  _______  _______  _______
(  ____ )(  ___  )(  ____ \\__   __/(  ____ \(  ____ )(  ____ \(  ____ \
| (    )|| (   ) || (    \/   ) (   | (    \/| (    )|| (    \/| (    \/
| (____)|| |   | || (_____    | |   | |      | (____)|| (__    | (_____
|  _____)| |   | |(_____  )   | |   | | ____ |     __)|  __)   (_____  )
| (      | |   | |      ) |   | |   | | \_  )| (\ (   | (            ) |
| )      | (___) |/\____) |   | |   | (___) || ) \ \__| (____/\/\____) |
|/       (_______)\_______)   )_(   (_______)|/   \__/(_______/\_______) 

I thought it was worth trying out, so I gave it a shot:

mysql> use postgres
ERROR 1049 (42000): Unknown database 'postgres'

Clearly I just need to create the database. Short work:

mysql> create database postgres;
Query OK, 1 row affected (0.00 sec)

mysql> use postgres
Database changed

So now I’m using Postgres. I still feel like I’m missing something, though. It feels a lot like reading XKCD comics. Where’s the tooltip?

Related posts:

1. Version 1.1.3 of improved Cacti graphs for MySQL released I’ve
2. How MySQL really executes a query WARNING: n
3. What do the InnoDB insert buffer statistics mean? Ever seen

Related posts brought to you by Yet Another Related Posts Plugin.

Follow 451 CAOS Links live @caostheory on Twitter and Identi.ca
“Tracking the open source news wires, so you don’t have to.”

For the latest on Oracle’s acquisition of MySQL via Sun, see Everything you always wanted to know about MySQL but were afraid to ask

# Yahoo! Open! Sourced! Traffic! Server!

# Red Hat launched Enterprise Virtualization for Servers for managing Linux and Microsoft Windows servers.

# 10gen, the company behind MongoDB, has raised $3.4m in a second round of funding.

# Talend updated its Open Profiler and Data Quality products.

# Tata Communications partnered with SugarCRM to provide on-demand CRM to customers in India.

# eZ Systems has appointed former IBM and BEA executive Christoph Rau as CEO.

# Bob Sutor offered his preliminary thoughts on starting an open source business.

# REvolution R Enterprise 3.0 is now available featuring R productivity environment for Windows.

# Skype confirmed it is creating an open-source Linux client.

# Monty Widenius claimed that MySQL’s main rivals has always been Oracle.

# Scalix has delivered Scalix Starter Packs, providing email and calendaring for home and small office use.

# Open source ad server vendor OpenX announced a partnership with Microsoft.

# Glyn Moody reported that the EU wants to re-define “closed” as “nearly open”.

# Munich’s use of Mozilla software surpassed Mozilla’s expectations.

# Matt Asay reported on why open source, like football/soccer is about big value, not big money.

# Mike Hogan examined how to protect FOSS -related revenues in an era of cloud services, focusing on Amazon RDS/MySQL.