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Welcome to the third installment of a series describing the Oracle Exadata platform. In part 1 we talked about hardware components, and in part 2 went on to discuss software. We now move on to how these components are packaged and licensed.

Unlike version 1 of the Oracle database machine, which was sold in full-rack increments only, version 2 introduces the concept of half and quarter rack configurations for smaller products. All database machines include a full-size physical rack for equipment, networking equipment including two redundant InfiniBand fabrics, the Cisco administrative switch, a KVM management unit, and power distribution units.
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Hello Folks,

As part of my preparation for the Exadata OCP Exam – Oracle Exadata 11g Essentials (1Z1-536), I was reading through the “Oracle® Exadata Storage Server Software User’s Guide” (not available publicly at the moment as far as I know). I found that in the Exadata world the two famous events “db file scattered read” and “db file sequential read” that cause so much confusion in Oracle DBAs’ minds are renamed to “cell multiblock physical read” and “cell single block physical read” accordingly.

Hopefully Oracle will port those events’ names to the RDBMS world as well in version 12c.

PS: I passed the Beta exam this morning. As with any beta, Oracle will release results after a period of time. ETA: 3-5 weeks from now.

Stay tuned, more info is coming,

Yury

As I work on putting together slides, I’d like to remind you all of my Oracle OpenWorld 2010 presentation, a customer case study migrating a complex data warehouse environment to Exadata. I’ll be presenting along with Michael Aldrich of LinkShare and Aiman al-Khammash of Oracle, and focusing on our own experience with Exadata, lessons learned, and advice for others choosing to implement Exadata.

The session will begin at half past noon on Monday in Moscone South, room 308. Here’s a link to import it into your calendar in ICS format

There is a little know fact that Oracle table compression doesn’t work with tables that have more than 255. It’s has been reported here and compression limitations in general here.

As a follow up from my previous post on Exadata Design, where I question the use of dimensions for certain attributes in data warehouses, I figured I should test whether HCC works with tables that have more than 255 columns.

And it does. Here’s my test case.

Setup:

create table ctest (
col_1  varchar2(30) default 'JUSTSOMEDATA',
col_2  varchar2(30) default 'JUSTSOMEDATA',
...
col_255  varchar2(30) default 'JUSTSOMEDATA'
);
insert into ctest (col_1) select 'OTHERDATA' from dba_objects;
insert /*+APPEND*/ into ctest select * from ctest;
commit;
insert /*+APPEND*/ into ctest select * from ctest;
commit;

Build various scenarios (NOTE: second create adds the 256th column):

/*REGULAR*/
create table ctest_cmp compress as select * from ctest;
create table ctest_cmp1 compress as select t.*, 'NEW' col_256 from ctest t;

/*HCC QUERY*/
create table ctest_hcc compress for query low as select * from ctest;
create table ctest_hcc1 compress for query low  as select t.*, 'NEW' col_256 from ctest t;

/*HCC ARCHIVE*/
create table ctest_hccA compress for archive low as select * from ctest;
create table ctest_hccA1 compress for archive low  as select t.*, 'NEW' col_256 from ctest t;

And the results:

SQL> select round((bytes)/1024/1024) as mb ,  segment_name from user_segments t where segment_name like 'CTEST%' order by segment_name;

        MB SEGMENT_NAME
---------- ----------------------------
       824 CTEST
         3 CTEST_CMP
       824 CTEST_CMP1
         1 CTEST_HCC
         1 CTEST_HCC1
         1 CTEST_HCCA
         1 CTEST_HCCA1

As of this afternoon, version 11.2.1.3.1 of Oracle’s Exadata storage server software, is out in the wild. This is the first publicly available version of the 11.2.1.3 branch, a major release including a full OS image with an update to Oracle Enterprise Linux 5.5. A number of bugs causing cell server crashes and hangs have been fixed, including 9472035, 9870117, and 9722560.
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Welcome to Log Buffer. The weekly review of DBA industry news. Enjoy Log Buffer #199.

Remember if you find a link or interesting blog post that you think Log Buffer should mention, send a note to the editor at Log Buffer and be sure to include the link, and a short note outlining why you think that particular post would be of value to other DBAs, or what you learned from reading it.

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Kicking off this week are posts recommended by Gwen Shapira who also took a few minutes to share her production advice for developers.
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One of the questions in my webinar this week related to TPC benchmark results for Exadata. Kevin Closson blogged about a TPC-H test run against an Exadata V1 machine back in June 2009. It was the fastest 1,000GB TPC-H result at the time, but has since been overtaken by a ParAccel result that makes a mockery of the benchmark according to Curt Monash by running almost entirely in RAM.

I’m not aware of any TPC results for Exadata V2. However a TPC-C test was run in late 2009 using a Sun F5100 flash array on Sun T5540 servers, setting a record for the benchmark that still stands.

The Oracle wiki has a great overview of the various benchmarks and what they actually measure.

We’re in the process of applying Exadata Bundle Patch 5, and ran into an issue I wanted to share.

Step 5 in the post-install instructions in the README says:

5. Recompile all invalid objects before using in catmet2

@?/rdbms/admin/utlrp.sql
@?/rdbms/admin/catmet2.sql

— recompile dbms_metadata_int to enable the diffing code
alter package dbms_metadata_int compile plsql_ccflags = ‘ku$xml_enabled:true’;

— recompile dbms_metadata_util to enable the xmlschema load code
alter package dbms_metadata_util compile plsql_ccflags = ‘ku$xml_enabled:true’;

========================================================================================

NOTE: If warnings are received after running the catmet2.sql and the alter
packages for dbms_metadata_int and dbms_metadata_util like below :

Received “Warning: Package altered with compilation errors.”

Please recompile those packages manually and re-run catmet2.sql:

alter package DBMS_METADATA_INT compile body;

alter package DBMS_METADATA_UTIL compile body;

@?/rdbms/admin/catmet2.sql

========================================================================================

The system didn’t have a XDB user, and likely because of this, the two “alter package” commands invalidated the dbms_metadata objects. The subsequent recompilations all failed. On advice from Oracle support, we ended up backing out the patch and re-applying without running these “alter package” commands, and confirmed that DBMS_METADATA works fine.

So if you don’t have XDB installed, skip the “alter package” commands. I hope the README is updated soon.

My article Making the Most of Oracle Exadata in the August 2010 issue of the NoCOUG Journal has come out. It covers Exadata’s feature set, and then dives deeper, discussing how to make the best use of its capabilities. For those of you not subscribers of the print edition, it’s also available electronically.
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Welcome to Log Buffer, a weekly review of the database industry. This week’s issue Log Buffer #198 is generously published by Sam DeFilippis, who manages Oracle Notes blogs, with latest postings on Oracle GoldenGate.

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Please enjoy Sam’s issue of Log Buffer #198.