Re: Taking export from SECONDARY_INSTANCE from 02 node RAC

From: Michael Austin <maustin_at_firstdbasource.com>
Date: Fri, 27 Feb 2009 12:35:50 -0600
Message-ID: <tmWpl.23685$ZP4.21421_at_nlpi067.nbdc.sbc.com>

Mladen Gogala wrote:
> On Thu, 26 Feb 2009 19:29:07 -0600, Michael Austin wrote:
>

>> I would caveat any discussion about licensing with "it all depends".

>
> Yes, of course. Oracle sales force is not unlike the car dealership.
> What, you think that $15,000 is too much for this only 4 years old
> Ford Taurus? No problem, I will lower the price, just for you, it's
> only $12,000 and I will throw in new tires, too. That is especially
> true if you are a big shop with a big name. I've seen some deals with
> cutting the prices in half - literally. Unfortunately, these days
> everybody is in dire need of money, especially the banks. Oracle cannot
> afford slashing the prices by much without layoffs.
>
> I do predict, however, that, during this crisis, many shops will turn to
> cheaper alternatives like PostgreSQL and MySQL, thus eventually forcing
> Oracle to cut the prices. My boss, an avid Oracle fan, started a pilot
> project for an office database with MySQL. I am an old oracle hack with
> many years of experience but I did accept the task to learn and manage
> MySQL. Should that go well, I am sure that we will see those projects
> multiply like rabbits. That is the thing that will eventually force Oracle
> to lower the prices and give some things like AWR report for free.
>
> I must say, though, that Oracle plans look so much nicer then this:
> mysql> explain select ar.artist_name,al.album_name
> -> from artist ar,album al
> -> where ar.artist_id=al.artist_id;
> +----+-------------+-------+------+---------------+---------+---------
> +---------
> -----------+------+-------+
> | id | select_type | table | type | possible_keys | key | key_len |
> ref
> | rows | Extra |
> +----+-------------+-------+------+---------------+---------+---------
> +---------
> -----------+------+-------+
> | 1 | SIMPLE | ar | ALL | PRIMARY | NULL | NULL |
> NULL
> | 6 | |
> | 1 | SIMPLE | al | ref | PRIMARY | PRIMARY | 2 |
> music.ar
> .artist_id | 1 | |
> +----+-------------+-------+------+---------------+---------+---------
> +---------
> -----------+------+-------+
> 2 rows in set (0.20 sec)
>
> mysql>
>
> This is a simple NESTED LOOPS join.
>
>

And there are many other performance issues as well as standards issues..

Try this in mysql and oracle: (and unless they fixed it- which they have not in my server...) will be very troubling to REAL database folks... Especially if you need to move data from MySQL to say a mainframe or COBOL app :-( And BTW per their crack[ed?] developer staff - this is NOT a BUG because it is "documented behavior".. How whacked is that!!!

create table mytest (a char(10));
insert into mytest values ('ABCDE');
select '|'||a||'|' from mytest;
select '|'||cast(a as CHAR(20))||'|' from mytest;

ORACLE: (correct result!!)
SQL> create table mytest (a char(10));
insert into mytest values ('ABCDE');
select '|'||a||'|' from mytest;
select '|'||cast(a as CHAR(20))||'|' from mytest;

Table created.

SQL>
1 row created.

SQL>
'|'||A||'|'

---

|ABCDE | <<--- note there are 5 chars+5spaces as per the data type.

SQL>
'|'||CAST(AASCHAR(20))

---

|ABCDE |

---

MySQL - the INCORRECT RESULT

mysql> create table mytest (a char(10)); Query OK, 0 rows affected (1.62 sec)

mysql> insert into mytest values ('ABCDE'); Query OK, 1 row affected (0.38 sec)

mysql> select '|'||a||'|' from mytest;
+-------------+
| '|'||a||'|' |
+-------------+
| |ABCDE| | <<--- note there are 5 chars only - no spaces. +-------------+
1 row in set (0.24 sec)

mysql> select '|'||cast(a as char(20))||'|' from mytest;

+-------------------------------+

| '|'||cast(a as char(20))||'|' |

+-------------------------------+
| |ABCDE|                       |
+-------------------------------+

1 row in set (0.11 sec) Received on Fri Feb 27 2009 - 12:35:50 CST