The last time I wrote this was just under 2 years ago!!! WoW. Things have changed. Sun bought MySQL, Oracle bought Sun. Those were bombshell deals. At least you can rest assured that some things can be constant. I still eat my daily serving of broccoli (among other healthful “things”). I urge you all to go the fridge and grab some veggies prior to sitting down for this week’s… ahem… digest.

Starting with Oracle, Pythian’s own Alex Fatkulin illustrates a bug (?…likely) that could lead to logically corrupted data. Doug Burns provides an update on his Hotsos 2010 trip with some serious thumbs-up action pointing in Tanel Poder’s direction and his affinity toward SQL*Plus.

Over at Mark Rittman’s Oracle Weblog, Venkatakrishnan J talks about Oracle Warehouse Builder 11gR2 – Importing Essbase Cubes using ODI Knowledge Modules – Part 1. This should drive the MySQL folks bonkers (in a good way) since he points to an example by David Allen to import MySQL Metadata over and vice versa.

Oracle Virtualization Blog’s Adam Hawley let everyone know about a Best Practices around Oracle VM with RAC RAC SIG webcast. It was on March 18th, but it was recorded and should be available online. I’m interested in this stuff so I included it here. I hope you can enjoy it too.

I had the honour to recently provide a training session at a customer site on tuning methods and tools. A key topic of the discussion was related to Oracle statistics and the CBO. It was timely that the Oracle Scratchpad’s Jonathan Lewis posted a series created by Doug Burns all about stats. Nice.

Has anyone ever told you (or maybe you deduced it on your own) that leaving out where clauses is a bad thing. Well, leave it to Charles Hooper on his Oracle Notes to prove to us that sometimes, they are actually more efficient for solving certain types of problems. In another excellent post titled Physical Reads are Very Fast, Why is this SQL Statement Slow Charles also dives into why a slow query is “actually” slow. There’s an interesting discussion taking place. More performance tuning goodness was posted by Joel Goodman discussing some interesting behaviour with Oracle Index Leaf Blocks contention. Tell RAC to Leave Your Leaves Alone! Kerry Osborne illustrates the use of an interesting hidden parameter (_high_priority_processes) to resolve “log file sync” issues.

Over on the other side of the fence in the MySQL world, Jay Pipes @ Join-Fu gives us some background on the MySQL Transaction Log. Vadim Tkachenko with the MySQL Performance Blog has a number of posts on Percona 9.1 as well as a list of related sessions at the 2010 MySQL conference. Check it out.

On a more somber note (and by somber I mean legal, we all hate legalese don’t we?), Giuseppe Maxia over at The Data Charmer discusses Protocol, the GPL, and how Bazaar can help. He also has some good takeaways from the Linux MySQL distros meeting in Brussels. Baron Schwartz at xaprb has a new tool he’d like the MySQL folks to take for a spin. Try mk-query-advisor, a new Maatkit tool. It uses heuristics to find problems in SQL. Please use it and give feedback!

Are you interested in MySQL Clustering? I am. Andew Morgan has a new post introducing a tutorial to Build MySQL Cluster 7.1 from source – including MySQL Cluster Connector for Java. With Alex Fatkulin maybe running into an as yet possibly, sort of , kinda non-discovered bug, it’s only fair we also get some vision into the dark side on the MySQL front. Shlomi Noach states But I DO want MySQL to say “ERROR”!.

Brian Aker invites readers to participate at this year’s O’Reilly MySQL User’s Conference where they will be doing their first ever Ignite talk series.

Lastly, Stewart Smith has a very good set of posts illustrating Stored Procedures/Functions for Drizzle. Check this out (from Stewart’s post).

drizzle> select libtcc("#include <string.h>\n#include <stdlib.h>\nint foo(char* s) { char *a= 0x199c610; strcpy(s, a); return strlen(s); }") as result;

+--------------+
| result       |
+--------------+
| Hello World! |
+--------------+
1 row in set (0.01 sec)

I dare you.

On to SQL Server….

Scary DBA SQL MVP Grant Fritchey discusses Undocumented Virtual Column: %%lockres% and also recaps the SNESSUG March Meeting.

Jamie Thomson gives keyboard junkies some tips to Kill your temp tables using keyboard shortcuts : SSMS. Anyone interested in distributed queries should read Buck Woody’s Using linked servers, OPENROWSET and OPENQUERY.

Finally, Aaron Bertrand says with conviction “Yes, you can benefit from both data and backup compression”.

Having now exhausted my supply of munchies, it is time for me to retire. I bid you all a fantastic week. Keep your data safe, folks.

Shakir

Let’s start by creating a simple table with a deferrable primary key:

SQL> create table def_bug(n number primary key deferrable initially deferred);

Table created

SQL> insert into def_bug values (1);

1 row inserted

SQL> insert into def_bug values (2);

1 row inserted

SQL> commit;

Commit complete

You can confirm that the primary key constraint is working fine by trying to insert a duplicate value:

SQL> insert into def_bug values (1);

1 row inserted

SQL> commit;

commit

ORA-02091: transaction rolled back
ORA-00001: unique constraint (SRC.SYS_C004070) violated

So far so good. Open a second session and execute the following update:

SQL> update def_bug set n=3 where n=2;

1 row updated

Do not commit yet and execute in your first session:

SQL> update def_bug set n=3 where n<=2;

The above update will block due to our second session holding a lock on the row where n=2. Now commit your second session…

SQL> update def_bug set n=3 where n=2;

1 row updated

SQL> commit;

Commit complete

…and then commit your first session:

SQL> update def_bug set n=3 where n<=2;

1 row updated

SQL> commit;

Commit complete

Take a look at the data now:

SQL> select * from def_bug;

         N
----------
         3
         3

Ouch! This was certainly unexpected. You can confirm that the primary key is still working by trying to insert a duplicate value again:

SQL> insert into def_bug values (3);

1 row inserted

SQL> commit;

commit

ORA-02091: transaction rolled back
ORA-00001: unique constraint (SRC.SYS_C004070) violated

It certainly looks like the update statement did not take into account deferrable constraint declared on the table during restart caused by the write consistency mechanism.

This week started out with me posting about International Women’s Day, and has me personally attending Confoo (Montreal) which is an excellent conference I hope to return to next year. I learned a lot from confoo, especially the blending nosql and sql session I attended.

This week was also the Hotsos Symposium. Doug’s Oracle Blog has a series of posts about Hotsos. If all this talk about conferences has gotten you excited, Joshua Drake notes that 14 days and the hotel is almost full for postgresql conference east which is March 25th-28th in Philadelphia. And the Oracle database insider notes that the Oracle OpenWorld call for papers is now open.

According to Susan Visser this week (ending tomorrow) is also read an e-book week. So if you have not already done so, read an e-book! She links a coupon for an e-book in the post.

Craig Mullins notes that the mainframe is a good career choice in Mainframes: The Safe IT Career Choice. He notes that the mainframe is still not dead:

People having been predicting the death of the mainframe since the advent of client/server in the late 1980s. That is more than 20 years! Think of all the things that have died in that timespan while the mainframe keeps on chugging away: IBM’s PC business, Circuit City, Koogle peanut butter, public pay phones, Johnny Cash… the list is endless.

In other career-related news, Antonio Cangiano is looking for [2] top-notch student hackers for a 16-month internship at IBM in Toronto starting in May. All the details, including how to apply, are in Cangiano’s blog post.

Willie Favero wants to know how you “solve the batch dilemma” for issues like “shrinking your batch window, designing your batch to play nicely with … OLTP” in how’s your batch workload doing? Perhaps Favero should read the updated batch best practices posted by Anthony Shorten.

Bryan Smith surveys a more personal question by asking if you go both ways and “manage both DB2 for Linux, UNIX, and Windows and DB2 for z/OS” in don’t ask, don’t tell, bi-platform DBAs. This week’s Log Buffer editor admits to being a tri-platform DBA — she has tried many platforms, and in fact, many databases (MySQL, Oracle, DB2, SQL Server, Sybase, Postgres and Ingres)!

Hari Prasanna Srinivasan promotes a patching survey in Oracle really wants to hear from you! Patching Survey.

Henrik Loeser explains what a deadlock and a hot spot are by using a real life analogy taken from a police report in deadlock and hot spot in real life.

Jamie Thomson asks why do you abbreviate schema names?. Shlomi Noach tries to solve the issue that “there is no consistent convention as for how to write [about table aliases in] an SQL query” in proper sql table alias use conventions. Noach also gives us a tip: faster than truncate.

Leons Petrazickis reminds us that “rulesets are chains” and it is important to have your rulesets in the proper order in iptables firewall pitfall.

Anyone interested in the history of MySQL AB will be informed after reading Dries Buytaert’s article.
Gavin Towey shares his software that helps centrally manage 120 MySQL servers in qsh.pl: distributed query tool For those who want to learn more about column-oriented databases, particularly in MySQL, Robin Schumacher of the InfiniDB blog announces that there is a MySQL University session recording on MySQL column databases now available. MySQL join-fu expert Jay Pipes has moved his blog to www.joinfu.com and starts with An SQL Puzzle and of course a follow up on the sql puzzle.

Ivan Zoratti is happy that finally, slides posted for the MySQL DW breakfast. Venu Anuganti gives you tips on one of the most common MySQL frustrations: optimizing subqueries in how to improve subqueries derived tables performance. Justin Swanhart posts the way in which he Gets Linux performance information from your MySQL database without shell access and emulates a ‘top’ CPU summary using /proc/stat and MySQL using the same method.

The Oracle Apps blog has an introduction to Oracle user productivity kit (UPK). Even though in this editor’s opinion the article is very sales-pitchy, it has valuable information, and does indeed live up to its promise:

UPK is a software tool that can capture all the steps in a system process. It records every keystroke, every click of the mouse, each menu option chosen and each button pressed. All this is done in the UPK Recorder by going through the transaction and pressing “printscreen” after every user action. From this, without any further effort from the developer, UPK builds a number of valuable outputs.

Allen White gives a great tip on how to optimize queries in keep your data clean.

Mike Dietrich reminds you to remove “old” parameters and events from your init.ora when upgrading, “as keeping them will definitely slow down the database performance in the new release.” He shows evidence of slowness when this is not done. Dietrich also shows how you can be gathering workload statistics “to give the optimizer some good knowledge about how powerful your IO-system might be”, especially “a few days after upgrading to the new release…while a real workload is running.”

Brian Aker shows the exciting features coming soon in Drizzle in Drizzle, Cherry, Roadmap for our Next Release.

Maybe you are thinking of migrating, not upgrading…..The O’Reilly Radar shows how to asses an Oracle to MySQL migration in MySQL migration and risk management. Actually, that article interviews Ronald Bradford on the subject — Bradford has been prolific lately, updating free my.cnf advice series and “Don’t Assume”: MySQL for the Oracle DBA series. Nick Quarmby also talks about migrating Oracle, but not to a new database, just to a new platform, in his primer on migrating Oracle Applications to new platforms. And the big news comes from Carlos of dataprix that Twitter will migrate from MySQL to Cassandra DB.

Paul S. Randal explains his way of benchmarking: 1 Tb table population on SQL Server.

Pete Finnigan shares his slides from a webinar on how to secure oracle, and Denis Pilipchuk shares his approaches for discovering security vulnerabilities in software applications.

Jeff Davis shares his thoughts about scalability and the relational model. Robert Treat responds actually, the relational model doesn’t scale and Baron Schwartz counters with NoSQL doesn’t mean non-relational.

Buck Woody explains “whenever you want to know something about SQL Server’s configuration, whether that’s the Instance itself or a database, you have a few options” — and of course what those options are — in system variables, stored procedures or functions for meta data.

This week’s T-SQL Tuesday topic was I/O. There are many links to great blog posts in the comments; three random posts I chose to highlight: Michael Zilberstein talks about IO capacity planning, while Kalen Delaney talks about using STATISTICS IO in I/O, you know, and Merrill Aldrich chimes in with information on real world SSD’s. Aldrich also begs folks not to waste resources and make more work for developers and DBAs in dear ISV, you’re keeping me awake nights with your VARCHAR() dates.

And we end with a bit of fin: Paul Nielsen wants us all to have a bit of fun; he has posted an SQL limerick and asks readers to create there own in there once was in Dublin a query.

I arrived at Omni Mandalay Hotel on Sunday evening with Dan Norris. I was flying through Chicago and it turned out that Dan was on the same flight and only few rows behind me. Small world.

Preparations for the conference were very chaotic on my part and, of course, I didn’t have either of my presentations ready. I was very stressed and getting sick as well — it looked like a complete disaster waiting to happen. I’d like to say that I was feeling like Doug Burns as he often managed to get sick just before a conference. Of course, I worked on my slides for the last few days as well as on the flight and presentation was slowly getting there but boy was I tired!

I quickly said hello to the crowd in the bar on the way to my room and rushed away to do some more damage to my slides. And then I had a brilliant idea — I could still see one of my best mates and do something good about my presentation! I asked Doug if he was interested in the preview (he probably wasn’t interested but he couldn’t say it to me) especially that my session wasn’t on his original agenda. Of course, that would mean that he had to leave a bunch of other good friends and spend some time tete-a-tete. Knowing Doug, this is some of the hardest thing to ask from him but it shows how good of a friend he is! (Plus, everyone thinks that he is anti-social anyway. Shhhh!)

Doug has made my day — while he provided lots of ideas and feedback on few things that I was lucking, he generally approved the idea and confirmed that it wasn’t totally crazy. I guess that was all I needed back then and Doug knew how nervous I was about it. (Thanks mate!)

So I called Sunday a day very early and went to bed before midnight. I really needed some sleep. Woken up by the alarm at 5AM (I woke up few times during the night looking at the clock — making sure I didn’t sleep through) and slides were ready just before lunch. I even managed to do a test run and it took 65 minutes — a wee bit too long for one hour session. But it was good test and I knew I had to be just a bit more concise in few parts.

Mi morning was very productive. Unfortunately, I missed the opening keynote from Tom Kyte. Such a pity! If what Doug wrote is true, Tom was talking about the mistakes we make *because* of our experience and our assumptions. This was exactly one of the points I was making in my Battle Against Any Guess — experience is danger. I wish I could see Tom’s example. Oh well, maybe another time.

I managed to attend half of the Richard Foote’s session on indexes but my mind was far away — with my own slides. Though, I did manage to focus on bitmap indexes part and the myth of bitmap indexes not working well for columns with high cardinality. Very interesting conclusions. I’m still wondering how much overhead updates will do to such bitmap index.

After lunch, it was my turn. I ordered few copies of the latest OakTable book — Expert Oracle Practices: Oracle Database Administration from the Oak Table — that I co-authored with the bunch of other Oakies. I contributed chapter 1 in the book titled just like my presentation — Battle Against Any Guess. The plan was to give a copy away during the presentation and do a draw for another one at the end of the session. I was so nervous that I forgot about it until the end of the session so I just did a draw for two copies. The lucky winners were Lynn-Georgia Tesch and Surendra Anchula. Congratulations! For the rest of you who left the contact details — please stay tuned and we’ll organize few things online.

Now the main topic of this post — my presentation. What’s unusual about this session is that it’s not some technical stuff that I usually do but a more conceptual and motivational talk. Could I pull it off? Well, I think it went fairly well in general even though I did identify few rough places and my lack of English language mastering. Might need to work a little bit more on the flow of the presentation.

We had quite a few good laughs. Later, people in the next hall were asking about it and Dan was making the jokes on the stage so it must have been loud. Anyway, I think nobody fell asleep and I managed to get people thinking about the topic. I received many “thank you” notes yesterday and compliments on a good session so by the end of the day I was more and more pleased. Thanks everyone for attending and especially big thanks to those of you who brought to my attention examples from their own battles. If you have more to discuss — contact me by email (my last name) {at} pythian.com.

Thanks to Marco Gralike for recording some fragments and sharing them. I think he has more to come.

This is the introductory couple minutes. You can definitely notice how nervous I am starting on the stage:

Solving the wrong problem example:

That’s all for now. Stay tuned — more to come.

Start planning your blog posts for Ada Lovelace day now (March 24th, http://findingada.com/ Ada Lovelace Day is an international day of blogging (videologging, podcasting, comic drawing etc.!) to draw attention to the achievements of women in technology and science.)

To that end, I would like to point out all the women currently in science and tech fields that I admire and think are doing great things. I think it would be great if everyone, male or female, made a list like this:

The women that have taught me science/tech along the way:

High School:
Mary Lou Ciavarra (Physics)
Maria Petretti (Pre-Algebra, and Academic Decathlon)
Reneé Fishman (Biology)
Lisa Acquaire (Economics during Academic Decathlon)

College:
Professor Kalpana White (Biology), and in whose fruit fly lab I worked for 2 semesters.
Professor Eve Marder (Introductory Neuroscience)

Though Brandeis does have female faculty in the Computer Science department, I did not manage to have any classes with female Computer Science faculty members.

My current female DBA co-workers at Pythian: Isabel Pinarci (Oracle), Michelle Gutzait (SQL Server), Catherine Chow (Oracle) and Jasmine Wen (Oracle).

And to folks in the greater MySQL/tech community and tech co-workers past and present, especially those I have been inspired and helped by: Tracy Gangwer, Selena Deckelmann (Postgres), Amy Rich, Anne Cross, and more (If I have forgotten you, I apologize!).

Oracle 11g Release 2 Grid Infrastructure has been dramatically redesigned compare to 10g and 11gR1 Clusterware. Coming with impressive set of new features, Grid Infrastructure also uses much more memory. While RAM is rather inexpensive these days, it does pose an inconvenience in some scenarios. Particularly, for sand-box type installations that I use all the time for my own tests and demonstrations. For production upgrades, you need to be aware of and plan for increased memory usage.

I’ve been able to easily run a 2 node 10g RAC cluster on my MacBook with 4 GB of RAM allocating less than 1 GB of RAM to each virtual machine. That was even enough for a mini database instance with a very small memory footprint. Oracle 11g Release 1 was pretty much the same except maybe the database instance itself required a bit more memory but one node could still fit within 1 GB of RAM.

In 11gR2, bare-bone Grid Infrastructure processes alone consume 10+ times more memory (11.2.0.1 on 32 bit Linux to be precise):

[gorby@cheese1 ~]$ ps -eo pid,%mem,rss,user,cmd --sort=rsz --cols 100 | grep -e '^ *PID' -e grid -e ohasd | grep -v grep
  PID %MEM   RSS USER     CMD
 3614  0.0  1080 root     /bin/sh /etc/init.d/init.ohasd run
 4322  0.2  3368 oracle   /nfs/11.2.0/grid/opmn/bin/ons -d
 4323  0.4  5164 oracle   /nfs/11.2.0/grid/opmn/bin/ons -d
 4117  0.6  7860 root     /nfs/11.2.0/grid/bin/oclskd.bin
 3830  0.6  8788 oracle   /nfs/11.2.0/grid/bin/gipcd.bin
 5048  0.7  8992 oracle   /nfs/11.2.0/grid/bin/tnslsnr LISTENER -inherit
 4167  0.7 10052 oracle   /nfs/11.2.0/grid/bin/evmlogger.bin -o /nfs/11.2.0/grid/evm/log/evmlogger.i
 3969  0.9 12412 oracle   /nfs/11.2.0/grid/bin/diskmon.bin -d -f
 3860  0.9 12736 oracle   /nfs/11.2.0/grid/bin/mdnsd.bin
 4067  1.1 14648 root     /nfs/11.2.0/grid/bin/octssd.bin reboot
 5016  1.2 15860 root     /nfs/11.2.0/grid/bin/orarootagent.bin
 3956  1.3 16964 root     /nfs/11.2.0/grid/bin/orarootagent.bin
 4292  1.4 17984 oracle   /nfs/11.2.0/grid/bin/oraagent.bin
 3874  1.5 20112 oracle   /nfs/11.2.0/grid/bin/gpnpd.bin
 3817  1.5 20300 oracle   /nfs/11.2.0/grid/bin/oraagent.bin
 4083  1.8 23700 oracle   /nfs/11.2.0/grid/bin/evmd.bin
 4372  2.4 31548 oracle   /nfs/11.2.0/grid/jdk/jre//bin/java -Doracle.supercluster.cluster.server=eo
 3564  3.2 41532 root     /nfs/11.2.0/grid/bin/ohasd.bin reboot
 4081  3.5 44932 root     /nfs/11.2.0/grid/bin/crsd.bin reboot
 3906 18.6 239428 root    /nfs/11.2.0/grid/bin/cssdagent
 3887 18.6 239444 root    /nfs/11.2.0/grid/bin/cssdmonitor
 3924 20.1 258564 oracle  /nfs/11.2.0/grid/bin/ocssd.bin

The second column above gives you amount of resident memory in KB for processes related to Grid Infrastructure. As you can cleanly see, processes of CSS components consume well above 700MB! In total we can account for 1 GB. (those calculations are flawed — see below)

Compare that with 10g (10.2.0.3 on 32 bit Linux) — bare-bone Clusterware processes consume only 60MB:

[oracle@lh1 ~]$ ps -eo pid,%mem,rss,user,cmd --sort=rsz --cols 100 | grep -e '^ *PID' -e nfs -e crs -e css -e evm | grep -v grep
  PID %MEM  RSS USER     CMD
 6524  0.0  348 oracle   /nfs1/oracle/oracle/product/10.2.0/crs/opmn/bin/ons -d
 4892  0.1  992 oracle   /bin/sh -c cd /nfs1/oracle/oracle/product/10.2.0/crs/log/lh1/cssd/oclsomon;
 3262  0.1 1072 root     /bin/sh /etc/init.d/init.evmd run
 3506  0.1 1100 root     /bin/sh /etc/init.d/init.crsd run
 4575  0.1 1116 root     /bin/su -l oracle -c sh -c 'ulimit -c unlimited; cd /nfs1/oracle/oracle/pro
 4890  0.1 1120 root     /bin/su -l oracle -c /bin/sh -c 'cd /nfs1/oracle/oracle/product/10.2.0/crs/
 4664  0.1 1180 root     /bin/sh /etc/init.d/init.cssd oclsomon
 3263  0.1 1188 root     /bin/sh /etc/init.d/init.cssd fatal
 4677  0.1 1188 root     /bin/sh /etc/init.d/init.cssd daemon
 6525  0.5 4792 oracle   /nfs1/oracle/oracle/product/10.2.0/crs/opmn/bin/ons -d
 4922  0.6 5224 oracle   /nfs1/oracle/oracle/product/10.2.0/crs/bin/oclsomon.bin
 5915  0.7 6280 oracle   /nfs1/oracle/oracle/product/10.2.0/crs/bin/evmlogger.bin -o /nfs1/oracle/or
 4576  1.1 9312 oracle   /nfs1/oracle/oracle/product/10.2.0/crs/bin/evmd.bin
 5018  1.1 9428 oracle   /nfs1/oracle/oracle/product/10.2.0/crs/bin/ocssd.bin
 4606  2.0 16712 root    /nfs1/oracle/oracle/product/10.2.0/crs/bin/crsd.bin reboot

The memory usage above is a bit overstated. There are some shared memory accounted multiple times. I could use Smaps interface to get better per process statistics. For example, you could see that 3 of the “top offenders” (CSS binaries) have about 40MB of shared libraries each:

[root@cheese1 ~]# ./smaps.pl 3924 | head
VMSIZE:     258576 kb
RSS:       258564 kb total
            39164 kb shared
             5180 kb private clean
           214220 kb private dirty
PRIVATE MAPPINGS
     vmsize   rss clean   rss dirty  file
   15052 kb        0 kb    15052 kb
   12016 kb        0 kb    12016 kb
   11184 kb        0 kb    11184 kb
[root@cheese1 ~]# ./smaps.pl 3887 | head
VMSIZE:     239456 kb
RSS:       239444 kb total
            40096 kb shared
             6200 kb private clean
           193148 kb private dirty
PRIVATE MAPPINGS
     vmsize   rss clean   rss dirty  file
   14624 kb        0 kb    14624 kb
   10240 kb        0 kb    10240 kb
   10240 kb        0 kb    10240 kb
[root@cheese1 ~]# ./smaps.pl 3906 | head
VMSIZE:     239440 kb
RSS:       239428 kb total
            40096 kb shared
             6200 kb private clean
           193132 kb private dirty
PRIVATE MAPPINGS
     vmsize   rss clean   rss dirty  file
   14624 kb        0 kb    14624 kb
   10240 kb        0 kb    10240 kb
   10240 kb        0 kb    10240 kb
[root@cheese1 ~]#

One way to get a practical number is to check system memory usage with and without Grid Infrastructure running — the difference is about 750MB (see the “free” column of the second row).

[root@cheese1 ~]# free
             total       used       free     shared    buffers     cached
Mem:       1283040    1131584     151456          0      18504     295668
-/+ buffers/cache:     817412     465628
Swap:       655328         76     655252
[root@cheese1 ~]# crsctl stop crs
CRS-2791: Starting shutdown of Oracle High Availability Services-managed resources on 'cheese1'
...
...
CRS-4133: Oracle High Availability Services has been stopped.
[root@cheese1 ~]# free
             total       used       free     shared    buffers     cached
Mem:       1283040     397144     885896          0      18640     316632
-/+ buffers/cache:      61872    1221168
Swap:       655328         76     655252
[root@cheese1 ~]# ps -eo pid,%mem,rss,user,cmd --sort=rsz --cols 100 | grep -e '^ *PID' -e grid -e ohasd | grep -v grep
  PID %MEM   RSS USER     CMD
 3614  0.0  1084 root     /bin/sh /etc/init.d/init.ohasd run

I don’t have 11gR1 test cluster handy so I can’t check 100% but Oracle 11g Release 1 Clusterware is not much different from 10g so memory usage must be similar.

The lesson is that if you are upgrading your Oracle RAC Cluster to 11gR2 from 10g or 11gR1, then you have to account for additional 700MB memory for Grid Infrastructure alone on each node. Note that, this doesn’t take into account higher memory usage of the database instances themselves.

Having recently moved his blog, Gary approached the Log Buffer coordinator to volunteer for an edition because he knows that, with LB being a popular and established destination in the database blogoshphere, it would help him broadcast his new blog and welcome readers to it. You can do it too–simply send an email to the Log Buffer coordinator.

Here’s Gary’s Log Buffer #181.

If you didn’t manage to attend my presentation, Oracle 11g ASM — The Evolution, during RMOUG or other conferences, you have a chance to see it online today. I’m doing it a web-cast at RAC SIG. It’s today, 4-Mar-10 at 12:00pm EST (9:00am PST).

I am not sure how much sense all this will make without my comments. We may do it in a webinar if there is sufficient interest. Regardless I will probably be doing it again at some point in the future.

Oracle

There was so much Oracle stuff this week that I’ve decided to cram a little more of it into Log Buffer by providing a little less context than usual.

Jonathan Lewis shares an explication of aliases: “I was asked the following question recently: ‘Does the use of table aliases affect performance?’ To which the best answer is probably ‘Yes, though in general you probably won’t notice the difference and there are reasons more imporant [sic] than performance for using table aliases.’”

Doug Burns continues his most recent series: Statistics on Partitioned Tables – Part 2, and Statistics on Partitioned Tables – Part 3.

Charles Schultz demonstrates how VPD + bad ANYDATA practices can really bite: “The point of my blog was that using CAST can really screw up your data. Oracle Support is filing a bug on this behavior, as it looks like an overflow problem.”

Pythian’s Gleb Otochkin begins a series on Oracle GoldenGate installation.

Guy Harrison provides a thorough introduction and recommendations on memory management for Oracle databases on VMWare ESX.

Robert Vollman returns to blogging and offers his 10-point plan on improving your SQL queries.

Jared Still sheds some light on a cool but unknown RMAN feature.

Richard Foote knocks holes in another myth: “One of the great myths in Oracle is that bitmap indexes are only suitable and should only be used with columns that have so-called low cardinality (few distinct) values.”

Alexander Kornbrust shares a link to a really good whitepaper about “Hacking Oracle from the Web” by Sumit Siddarth.

Eddie Awad shares a link to a SQL injection prevention cheat sheet.

Charles Hooper answers the question, What is the meaning of the %CPU column in an explain plan?.

Meanwhile, Harald van Breederode does the same for this one: Why does the size of my ORACLE_HOME increase?

SQL Server

Thomas LaRock gives an recap of MS’s 2010 MVP Summit. Quotable take-away: “If I had to compare SQL 2008 R2 to SQL Server 4.0, I would say the difference is the same as comparing an F1 race car to a Chevy Vega.”

Half a world away, there is the SQLSocial Event – London March 16th, as advertised by Simon Sabin.

Simon also shares a script to get indexes and their included columns, beginning, “I get increasingly frustrated with the lack of visibility of included columns in management studio and from the system stored procedures sp_… This is a query that returns all indexes and there key and include columns[.]”

Andy Leonard throws us another nourishing SSIS snack: conditional split outputs.

Here’s Rob Farley with a book review of an oldie but a goodie: Inside SQL 2005 Query Tuning and Optimization, by Kalen Delaney et al. “If you spend any time tuning SQL Server databases, then this book will feel much thicker than it really is, and you’ll be finding useful information on just about every page.”

Thomas LaRock, meanwhile, writes that SQL Server 2008 Query Performance Tuning Distilled is
a good way to start your day. “Each morning, while I wait for my desktop to boot, I pick up their book, turn to any page, and just start reading.”

MySQL

Sticking with the theme a little longer, here is Baron Schwartz with a review of Understanding MySQL Internals by Sasha Pachev. “I should have read this book a long time ago, and it’s my loss that I didn’t.  . . .  Overall, this book is easily a high 4 stars on a scale of 5, and again, anyone seriously using MySQL should have it.”

Baron also shares a link to Oracle guy Cary Millsap’s Thinking Clearly about Performance paper.

Brian “Krow” Aker starts an extensive conversation with his post, Protocols, The GPL, Influences from MySQL. His thesis, “MySQL was the company that had the most influence on how companies and investors viewed the GPL.”

Paul Vallée of Pythian responds with his ideas on product management, effective developers, and the future of MySQL. “ . . . the future of MySQL, Drizzle, Monty Program, the Percona fork, etc.” to be more precise.

Colin Charles provides news of what’s been happening recently in MariaDB #1.

Mohammad Lahlouh wonders, can I use latin1 to store utf8 data? and gets several answers from his readers.

He might have asked Ronald Bradford, who knows this stuff. Here is his post on migrating MySQL latin1 to utf8 – character set options.

Pursuing a similar matter (collations), Roland Bouman opines, the best stored routine is the one you don’t write.

PostgreSQL

Baron Schwartz again! He announces, mk-query-digest now supports Postgres logs.

David Fetter says, part(ition)ing is such sweet sorrow. “There are excellent references on partitioning tables that depend on one table, but what happens when you need to partition the referenced table? Let’s find out!”

Bruce Momjian is here with news on the Python driver confusion.

Jon Jensen of End Point’s Blog posts a HOWTO on PostgreSQL EC2/EBS/RAID 0 snapshot backup.

NoSQL, Etc.

Chen Shapira has been at the compass and protractor, mapping the NoSQL space and returns from terra incognita unscathed.

Ronald Bradford has been getting started with Cassandra, one of the outposts on Chen’s map, and shares his steps.

Arnie Rowland says, “Mark your calendar! Portland SQLSaturday/CodeCamp/Barcamp 2010 is scheduled for May 22, 2010, at the University of Portland campus.  . . .  Portland SQLSaturday is encouraging presentations related to interoperability of any of the SQL platforms, including T-SQL (SQL Server), PostgreSQL, MySQL, and PL-SQL. Abstracts for Platform specific sessions are also encouraged.”

Okay, that is all for this edition. You guys are running me ragged! Fortunately, Gary Myers picks it up next week on his Sydney Oracle Lab. Till then!