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Database Feed

Oracle Database, Oracle 10g, Oracle 11g, Oracle XE, Oracle RAC, Oracle Instant Client, Oracle Data Guard and Oracle Exadata resources, news, and support articles.

SQL Profiles Disable Automatic Dynamic Sampling

I had an interesting email exchange with a fellow Oracle practitioner, Bryan Grenn, about differences between SQL Profiles and Baselines last week. Basically Bryan observed that SQL Profiles appeared to disable Dynamic Sampling on Global Temporary Tables while Baselines did not. This caused the optimizer’s cost calculations (and therefore the estimated elapsed runtimes) to be [...]

Spin tales: Part 1. Exclusive latches in Oracle 9.2-11g

How does Oracle process spin for a latch? How many times does it check the latch before going to sleep? Anyone knows. This is the _spin_count=2000. Two thousand cycles by default. Oracle established this value long ago in version 6 at the beginning of 90s. However, let me count. My previous investigation showed that latch [...]

What is the default for a METHOD_OPT value using SIZE REPEAT?

Past experience has always led me to believe that a METHOD_OPT value of “FOR ALL COLUMNS SIZE REPEAT” would default to “SIZE 1″ on columns without statistics. I have never explicitly tested this default however so this is the quick test I did to put my mind at rest.

First we create a test table that, being new, has never had any queries on it. Therefore “SIZE AUTO” should not create any histograms.

SOAP Server in PL/SQL

Or how to expose PL/SQL packages as SOAP web services using pure PL/SQL

I have blogged before about the various options available for both consuming and exposing SOAP web services using PL/SQL.

Profiles, Password and Resource Control for Oracle Database XE

In this fifth part of a ten-part series on securing Oracle Database XE, you'll learn about profiles as they pertain to password and resource control. This article is excerpted from chapter 31 of the book Beginning PHP and Oracle: From Novice to Professional, written by W. Jason Gilmore and Bob Bryla (Apress; ISBN: 1590597702).
- Profiles and Password Control

Table 31-3 shows the password-related profile parameters.

last 2010 huzzah

2010 was a bit of a roller coaster...

First, the passing of four very good friends and colleagues:

- John Alexander Wildgoose, a fellow dba and IT pro as well as my long time golf buddy and friend.
- Dr. Paulo Abrantes, a very good adolescence friend I hadn't seen in many years, who quietly passed away recently. I do miss our talks about the future, Paulo.
- Noel Vanspaal, my database

FTP 421 service not available tcp wrapper hosts.allow

Files /etc/hosts.allow and /etc/hosts.deny control tcp wrapper permissions for incoming requests to linux servers. Ftp access is normally controlled by the ‘vsftpd’ line, e.g.: vsftpd: 138.134.116. 138.134.117. That would allow ftp connections from IP addresses like 138.134.116.x and 138.134.117.x. If your IP address is not in the allow list, ftp attempts will fail with an [...]


I’ve lost count of the number of times I’ve said something like: “Ideally you really need to do your testing on the production system”. Kevin Closson has recently written some interesting notes (with more to come) about clonedb – an 11.2 feature that may make it possible to get pretty close to this ideal. Part [...]

How to move table containing LONG or LOB columns?

Today a friend of mine asked me how to move a table having LONG datatype.As per him, when he fired alter table table_name move tablespace , he got “ORA-00997: illegal use of LONG datatype”.In past, i had moved the tables to the other tablespace but had not faced this error.So, it was time to do

New Environments, New DBA Crushes…

Just about any DBA you speak with will admit to having at least one other DBA they follow on the web, seek out when the present at conferences or search out when purchasing technical books. I jokingly refer to these as DBA crushes, (which really annoys my male coworkers when I tell them they are “DBA crushing” when the arena is also predominently male… :) )

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