Here is a brief description, taken from their site:

The Ruby Toolbox gives you an overview of these tools, sorted in categories and rated by the amount of watchers and forks in the corresponding source code repository on GitHub so you can find out easily what options you have and which are the most common ones in the Ruby community.

They basically list Ruby libraries by category and ‘popularity’ (defined above.)  I think it’s really interesting how influential GitHub has been to Ruby development, and in my opinion it is only natural that sites like The Ruby Toolbox are created.  I like the site because it lets me quickly choose candidates for evaluation when I am looking for a library to help with a particular task.

Stop the database and make sure that no instance has mounted the controlfile:

srvctl stop database -d db1

Now, log onto the database, start it in nomount mode and set the control_files parameter:              

sqlplus / as sysdba              
startup nomount             
alter system set control_files = +DATA/db1/controlfile/current_controlfile_1.ctl','+DATA/db1/controlfile/current_controlfile_2.ctl'

scope = spfile sid = '*';
exit;

Next, log into RMAN and copy the controlfiles to the new destination:              

rman target=/              
restore controlfile to '+DATA/db1/controlfile/current_controlfile_1.ctl'
from '+DATA/db1/controlfile/Current.controlfile.260.3462344';                          
restore controlfile to '+DATA/db1/controlfile/current_controlfile_2.ctl' from
'+DATA/db1/controlfile/Current.controlfile.260.3462344';              
exit; 

Finally,  shutdown and startup the database:              

sqlplus / as sysdba              
shutdown immediate              
exit;              
srvctl start database -d db1

The database should start up using your new controlfiles.  You can use ASMCMD to delete the old controlfile once everything is verified to be working with the new controlfiles.

You can find the article here, and his main site (excellent!) is here: http://www.martinfowler.com

I stumbled across the article while exploring deployment/system administration options utilizing Ruby. Because I am using RAC for my database instances, I have multiple servers that I need to consistently update with scripts, configuration, data, etc. I have been looking into Capistrano for this task (even though it is an Oracle system) and it looks promising, if a bit kludgy to implement without SCM in place and accessible from the server.

Once I have the deployment solution figured out, I’ll write it up.

ActiveRecord handles LOB inserts in two steps:

1. The data is inserted into the database and the LOB field is initialized with an empty lob.
2. The record is updated with the provided LOB data, replacing the empty lob.

As part of step 1 above, ActiveRecord pre-fetches the sequence that is used to populate the primary key field of the table. If you then have a trigger on that table that updates the incoming primary key column with the next sequence value, your Ruby object and the data inserted into the database are out of sync. Therefore, in step
2 of the LOB insert process described above, ActiveRecord is attempting to update a row with a primary key value that does not exist and no LOB values are ever populated.

To prevent this, I created the following code that alters ActiveRecord::Base and ActiveRecord::ConnectionAdapters::OracleAdapter to use the trigger-generated key (via the Oracle ‘RETURNING’ clause) in the AR object.
[ruby]

module ActiveRecord
module ConnectionAdapters #:nodoc:
class OracleAdapter < AbstractAdapter
def insert(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil) #:nodoc:
cursor = @connection.parse(sql)
log(sql, name) { cursor.exec(0) }
# return the primary key value for the record just inserted
cursor[1]
end
end
end

class Base
# Creates a record with values matching those of the instance attributes and
# returns its id.
def create
if self.id.nil? && connection.prefetch_primary_key?(self.class.table_name)
self.id = connection.next_sequence_value(self.class.sequence_name)
end

quoted_attributes = attributes_with_quotes

statement = if quoted_attributes.empty?
connection.empty_insert_statement(self.class.table_name)
else
“INSERT INTO #{self.class.quoted_table_name} ” +
“(#{quoted_column_names.join(’, ‘)}) ” +
“VALUES(#{quoted_attributes.values.join(’, ‘)}) returning #{self.class.primary_key} into :1″
end

self.id = connection.insert(statement, “#{self.class.name} Create”,
self.class.primary_key, self.id, self.class.sequence_name)

@new_record = false
id
end
end
end
[/ruby]

Now, this is really, really rough. I am using the 2.x version of ActiveRecord, and any updates to these sections in future releases will break my changes. It does, however, work for me right now. As I have time I will refactor this and increase its maintainablility.

Comments?

What is this place about?

ThoughtHook is a place where I can share my thoughts and ideas about surviving and thriving in the jungle that is software development. I relish programming in Ruby, so much of what I post about will be ruby-related (not necessarily Rails-related.) You will also see posts about Programming Languages, Oracle, PL/SQL, general coding, etc.; Whatever interests me and/or is relevant to my current work.

So now you have a better idea of what I am trying to do here. Hopefully, we can all learn from each other.