Alejandro Vargas

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Oracle Blogs
Updated: 1 hour 28 min ago

Oracle RDBMS Home Install Using Cloning

Wed, 2010-11-17 00:40

Using a standard Oracle Home, that is updated to the last patches, as the source to install new Oracle Homes can save a lot of time, compared to installing the same Oracle Home + Patches from scratch.

The procedure to clone an Oracle Home is simple and is well documented on a set of My Oracle Support documents that can be found on Document 1154613.1 ordered by release.

On this post I'm providing a step by step example of cloning a 11g R2 Home: How to clone a 11g R2 Oracle Home

This is nice to have solution if you need to make multiple installs on many servers. Yo do one install + patches, then move that copy over to all other servers.

Categories: DBA Blogs

Oracle RDBMS Home Install Using Cloning

Wed, 2010-11-17 00:40

Using a standard Oracle Home, that is updated to the last patches, as the source to install new Oracle Homes can save a lot of time, compared to installing the same Oracle Home + Patches from scratch.

The procedure to clone an Oracle Home is simple and is well documented on a set of My Oracle Support documents that can be found on Document 1154613.1 ordered by release.

On this post I'm providing a step by step example of cloning a 11g R2 Home:
How to clone a 11g R2 Oracle Home

This is nice to have solution if you need to make multiple installs on many servers. Yo do one install + patches, then move that copy over to all other servers.

Categories: DBA Blogs

Data Guard for Manual Failover, Step by Step

Sat, 2010-11-13 17:14

about:blankIn this post I'm showing the steps used to implement a manual failover scenario. My customer did not want to enable fast start failover but to leave the decision to failover in case of a major crash to the management team.

In the example I'm providing here I did configure flashback database with a one hour retention time so that the OS team can have this time to solve any issues on the primary, if they succeed to solve the problem in this time then the old primary can be easily reinstated as the new standby, other wise it will need to be recreated from a backup taken from the new primary

All details of this experience can be found on this document "Step by Step Configuration of a Physical Standby Database for Manual Failover"

Categories: DBA Blogs

Data Guard for Manual Failover, Step by Step

Sat, 2010-11-13 17:14

about:blank


In this post I'm showing the steps used to implement a manual failover scenario. My customer did not want to enable fast start failover but to leave the decision to failover in case of a major crash to the management team.

In the example I'm providing here I did configure flashback database with a one hour retention time so that the OS team can have this time to solve any issues on the primary, if they succeed to solve the problem in this time then the old primary can be easily reinstated as the new standby, other wise it will need to be recreated from a backup taken from the new primary

All details of this experience can be found on this document "Step by Step Configuration of a Physical Standby Database for Manual Failover"

Categories: DBA Blogs

How to Calculate TCP Socket Buffer Sizes for Data Guard Environments

Wed, 2010-05-19 05:31

The MAA best practices contains an example of how to calculate the optimal TCP socket buffer sizes, that is quite important for very busy Data Guard environments, this document Formula to Calculate TCP Socket Buffer Sizes.pdf contains an example of using the instructions provided on the best practices document.

In order to execute the calculation you need to know which is the band with or your network interface, usually will be 1Gb, on my example is a 10Gb network; and the round trip time, RTT, that is the time it takes for a packet to make a travel to the other end of the network and come back, on my example that was provided by the network administrator and was 3 ms (1000/seconds)

Categories: DBA Blogs

How to Calculate TCP Socket Buffer Sizes for Data Guard Environments

Wed, 2010-05-19 05:31

The MAA best practices contains an example of how to calculate the optimal TCP socket buffer sizes, that is quite important for very busy Data Guard environments, this document Formula to Calculate TCP Socket Buffer Sizes.pdf contains an example of using the instructions provided on the best practices document.

In order to execute the calculation you need to know which is the band with or your network interface, usually will be 1Gb, on my example is a 10Gb network; and the round trip time, RTT, that is the time it takes for a packet to make a travel to the other end of the network and come back, on my example that was provided by the network administrator and was 3 ms (1000/seconds)

Categories: DBA Blogs

Impact of Truncate or Drop Table When Flashback Database is Enabled

Wed, 2010-05-19 04:51

Recently I was working on a VLDB on the implementation of a disaster recovery environment configured with data guard physical standby and fast start failover.

One of the questions that come up was about the overhead of truncating and dropping tables. There are daily jobs on the database that truncate extremely large partitions, and as note 565535.1 explain, we knew there is an overhead for these operations.

But the information on the note was not clear enough, with the additional information I've got from Senior Oracle colleagues I did compile this document "Impact of Truncate or Drop Table When Flashback Database is Enabled" that further explain the case

Categories: DBA Blogs

Impact of Truncate or Drop Table When Flashback Database is Enabled

Wed, 2010-05-19 04:51

Recently I was working on a VLDB on the implementation of a disaster recovery environment configured with data guard physical standby and fast start failover.

One of the questions that come up was about the overhead of truncating and dropping tables. There are daily jobs on the database that truncate extremely large partitions, and as note 565535.1 explain, we knew there is an overhead for these operations.

But the information on the note was not clear enough, with the additional information I've got from Senior Oracle colleagues I did compile this document "Impact of Truncate or Drop Table When Flashback Database is Enabled" that further explain the case

Categories: DBA Blogs

Oracle Database 11g Underground Advice for Database Administrators, by April C. Sims

Wed, 2010-05-19 04:34

Recently I have received a request to review the book "Oracle Database 11g Underground Advice for Database Administrators" by April C. Sims

I was happy to have the opportunity to know some details about the author, she is an active contributor to the Oracle DBA community, through her blog "Oracle High Availability" .

The book is a serious and interesting work, I think it provides a good study and reference guide for DBA's that want to understand and implement highly available environments.

She starts walking over the more general aspects and skills required by a DBA and then goes on explaining the steps required to implement Data Guard, using RMAN, upgrading to 11g, etc.

Categories: DBA Blogs

Oracle Database 11g Underground Advice for Database Administrators, by April C. Sims

Wed, 2010-05-19 04:34

Recently I have received a request to review the book "Oracle Database 11g Underground Advice for Database Administrators" by April C. Sims

I was happy to have the opportunity to know some details about the author, she is an active contributor to the Oracle DBA community, through her blog "Oracle High Availability" .

The book is a serious and interesting work, I think it provides a good study and reference guide for DBA's that want to understand and implement highly available environments.

She starts walking over the more general aspects and skills required by a DBA and then goes on explaining the steps required to implement Data Guard, using RMAN, upgrading to 11g, etc.

Categories: DBA Blogs

The Next RAC, ASM and Linux Forum. May 4, 2010 Beit HP Raanana

Tue, 2010-04-27 18:39

The next RAC, ASM and Linux forum will take place next week, you are still on time to register : Israel Oracle Users Group RAC,ASM and Linux Forum

This time we will have a panel formed by Principal Oracle Advanced Customer Services Engineers and RAC experts Galit Elad and Nickita Chernovski and Senior Oracle Advanced Customer Services Engineers and RAC experts Roy Burstein and Dorit Noga.

They will address the subject: 5 years of experience with RAC at Israeli Customers, lessons learned. It is a wonderful opportunity to meet with the people that is present at most major implementations and helped to solve all major issues along the last years.

In addition we will have 2 most interesting Customer Presentations:

Visa Cal DBA Team Leader Harel Safra will tell about their experience with scalability using standard Linux Servers for their mission critical data warehouse.

Bank Discount Infrastructure DBA Uril Levin, who is in charge of the Bank Backup and Recovery Project, will speak about their Corporate Backup Solution using RMAN; that includes an end to end solution for VLDBS and mission critical databases. One of the most interesting RMAN implementations in Israel.

This time I will not be able to attend myself as I'm abroad on business, Galit Elad will greet you and will lead the meeting.

I'm sure you will enjoy a very, very interesting meeting.

Beit HP is located at 9 Dafna Street, Raanana

Best Regards

Alejandro


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Categories: DBA Blogs

Cloning A Database On The Same Server Using Rman Duplicate From Active Database

Sat, 2010-03-20 01:16

To clone a database using Rman we used to require an existing Rman backup, on 11g we can clone databases using the "from active" database option.

In this case we do not require an existing backup, the active datafiles will be used as the source for the clone.

In order to clone with the source database open it must be on archivelog mode. Otherwise we can make the clone mounting the source database, as shown in this example.


These are the steps required to complete the clone:


  1. Configure The Network

  2. Create A Password File For The New Database

  3. Create An Init.Ora For The New Database

  4. Create The Admin Directory For The New Database

  5. Shutdown And Startup Mount The Source Database

  6. Startup Nomount The New Database

  7. Connect To The Target (Source) And Auxiliary (New Clone) Databases Using Rman

  8. Execute The Duplicate Command

  9. Remove The Old Pfile

  10. Check The New Database

A step by step example is provided on this file: rman-duplicate-from-active-database.pdf

Categories: DBA Blogs

Compression for tables with more than 250 columns

Sun, 2010-02-28 19:15

Compression for tables with more than 250 columns

Tables with more than 250 columns are not supported to be compressed, this restriction remains in place even on 11g R2.

On the 11g R2, Sql Language Reference Manual, page 16-36 we can read:

Restrictions on Table Compression

* COMPRESS FOR OLTP and COMPRESS BASIC are not supported for tables with more than 255 columns.

This is a serious limitation specially for Telecoms where CDR tables can have a number of columns way over 255.

The available workaround:


  • Split the table into 2 sub-tables.

  • create table A as select pk,field 1 to 150 from origtable

  • create table B as select pk,field 151 to 300 from origtable

  • Each one will have less than 250 rows.

  • They will be joined by the primary key.

  • The table will be accessed using a view that has all the columns of the original table.

  • create view origtable as select a.pk,field a.1 to a.150, field b.151 to b.300 from a, b where a.pk=b.pk

Categories: DBA Blogs

RAC, ASM and Linux Forum, December 15, 13:30 - 18:00 Beit HP Raanana

Sun, 2009-12-13 03:04

It's time for our 2nd, 2009 RAC, ASM and Linux Forum in Tel Aviv!

I would like to warmly invite you to our next RAC, ASM and Linux forum to be held at Beit HP in Raanana, on December 15.

You can register on the Israel Oracle User Group site.

On this forum we will have a 11g R2 Technology Update and 2 very interesting Customer Presentations about minimum downtime VLDB Migration to RAC on Linux and Creating and Managing RPM's for Oracle Silent Install on Linux.

Panel on Grid Infrastructure, ASM, Clusterware and RAC 11g R2, Technology Update

Annie Flint, Principal Member of Technical Staff, Oracle Corporation
Ofir Manor, Senior Sales Consultant, Oracle Israel
Alejandro Vargas, Principal Support Consultant, Oracle Advanced Customer Services

In the few months since last forum on June many things happened, 11g Release 2 is already production and brought a revolution in terms of performance and deep changes to the world of ASM, Oracle Clusterware and RAC.

Exadata Release 2 was released opening the way for OLTP databases based on the new Oracle - Sun Database Machine.

In this seminar we will review the new face of ASM, Oracle Clusterware and RAC on 11g Release 2 and we will comment on some of the incredible performance enhancements of the new version.

Migration of a VLDB to RAC 11g with Minimal Downtime

Dotan Mor,
Senior DBA
Pelephone DBA Team

Dotan will tell us the whole story of migrating an 8TB Datawarehouse, with near 0 downtime, from Linux 3 with OCFS2 to Linux 5, with CRS, RAC and ASM 11g, and Infiniband; and how his customer still cannot believe the incredible improvements they got in performance.

He will tell us also all the several problems faced in the way to this big success and how all of them were overcome.

Packaging Application and Database Together On Linux for Super-Silent-Installs

Liron Amitzi,
VP Professional Services
Brillix

Liron will explain us how to build a Linux RPM that contains inside the whole set of files required to easily and fast deploy a complete application, from the database to last application executable.

See you there!

Best Regards,

Alejandro

Categories: DBA Blogs

Check IO Scripts

Wed, 2009-12-09 19:32

These scripts are very useful to check throughput.

The original version can be found on My Oracle Support Note 422414.1 by Luca Canali.

set lines 250 pages 50000

alter session set nls_date_format='dd-mm-yyyy hh24:mi';

col Phys_Read_Total_Bps for 999999999999
col Phys_Write_Total_Bps for 999999999999
col Redo_Bytes_per_sec for 999999999999
col Phys_Read_IOPS for 999999999999
col Phys_write_IOPS for 999999999999
col Phys_redo_IOPS for 999999999999
col OS_LOad for 999999999999
col DB_CPU_Usage_per_sec for 999999999999
col Host_CPU_util for 999999999999
col Network_bytes_per_sec for 999999999999
col Phys_IO_Tot_MBps for 999999999999
col Phys_IOPS_Tot for 999999999999

spool io_max_checkup.log

select min(begin_time), max(end_time),
sum(case metric_name when 'Physical Read Total Bytes Per Sec' then maxval end) Phys_Read_Tot_Bps,
sum(case metric_name when 'Physical Write Total Bytes Per Sec' then maxval end) Phys_Write_Tot_Bps,
sum(case metric_name when 'Redo Generated Per Sec' then maxval end) Redo_Bytes_per_sec,
sum(case metric_name when 'Physical Read Total IO Requests Per Sec' then maxval end) Phys_Read_IOPS,
sum(case metric_name when 'Physical Write Total IO Requests Per Sec' then maxval end) Phys_write_IOPS,
sum(case metric_name when 'Redo Writes Per Sec' then maxval end) Phys_redo_IOPS,
sum(case metric_name when 'Current OS Load' then maxval end) OS_LOad,
sum(case metric_name when 'CPU Usage Per Sec' then maxval end) DB_CPU_Usage_per_sec,
sum(case metric_name when 'Host CPU Utilization (%)' then maxval end) Host_CPU_util, --NOTE 100% = 1 loaded RAC node
sum(case metric_name when 'Network Traffic Volume Per Sec' then maxval end) Network_bytes_per_sec,
snap_id
from dba_hist_sysmetric_summary
group by snap_id
order by snap_id;

spool off

spool io_maxtot_summary.log

select min(begin_time), max(end_time),
sum(case metric_name when 'Physical Read Total Bytes Per Sec' then maxval end)/1024/1024 +
sum(case metric_name when 'Physical Write Total Bytes Per Sec' then maxval end)/1024/1024 +
sum(case metric_name when 'Redo Generated Per Sec' then maxval end)/1024/1024 Phys_IO_Tot_MBps,
sum(case metric_name when 'Physical Read Total IO Requests Per Sec' then maxval end) +
sum(case metric_name when 'Physical Write Total IO Requests Per Sec' then maxval end) +
sum(case metric_name when 'Redo Writes Per Sec' then maxval end) Phys_IOPS_Tot,
sum(case metric_name when 'Current OS Load' then maxval end) OS_LOad,
sum(case metric_name when 'CPU Usage Per Sec' then maxval end) DB_CPU_Usage_per_sec,
sum(case metric_name when 'Host CPU Utilization (%)' then maxval end) Host_CPU_util, --NOTE 100% = 1 loaded RAC node
sum(case metric_name when 'Network Traffic Volume Per Sec' then maxval end) Network_bytes_per_sec,
snap_id
from dba_hist_sysmetric_summary
group by snap_id
order by snap_id;

spool off

Categories: DBA Blogs

RAC install root.sh fail on 2nd Node with error: "Timed out waiting for the CRS stack to start"

Mon, 2009-11-30 20:51

Yesterday we spent the day trial to solve this problem.

The actual solution, once the problem was found, took a couple of minutes to solve.

Usually this issue will arise when there is a network misconfiguration. We did check that carefully and everything was well configured:

- Same device names at both ends
- No dropped packets or transmission errors
- Both sides configured full duplex

Then we decided to move the install software to the second node and used scp over the interconnect:

scp -r -priv:

scp progressed for a while and then become stalled.

Retrying using the public network worked without any problem.

Any other test using the interconnect got stalled after a while.

The network people checked what the problem can be and found that the switch was configured half duplex.

They corrected the problem and everything worked fine.

Oracle Support Note 745215.1 describe the problem and other areas to check as well.

Categories: DBA Blogs

ASM Hands-On Training, Server Enviroment Setup And Aliases

Sat, 2009-09-12 05:37

The server where the labs of the ASM Hands-On Training works is configured with tcsh as the default oracle user shell.

A .cshrc file containing several aliases was setup to easy moving around and executing repetitive commands.

On this document there is a general explanation of how the environment can be used.

Details on this file: Server Enviroment Setup And Aliases

Categories: DBA Blogs

ASM Hands-On Training, Lab 21, ASMCMD Use And Options

Sat, 2009-09-12 05:27

On this lab we will review some of the useful set of commands provided by the ASM command line utility.

Some of the asmcmd commands display information, these information is based on v$asm views, other commands actually make changes to the structure like mkdir or rm.

Details on file: ASMCMD Use And Options

Categories: DBA Blogs

ASM Hands-On Training, Lab 20, Storage Consolidation With ASM

Sat, 2009-09-12 05:22

On this lab we will share our ASM disks with a second server and we will open the sati12 database on it.

To do that we copied the vm to another location, without including the ASM disks, that are located on a separate folder, this way the second vm is pointing to the same ASM disks as the first one.

Details on file: Storage Consolidation With ASM

Categories: DBA Blogs

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