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Published on 2010-06-16T16:56:19Z
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I have a query
SELECT foo FROM bar WHERE some_column = ?
How do I get a explain plan from MySQL without filling in a value for the parameter?
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I tried everything till now:
sudo apt-get remove mysql-server mysql-client mysql-common
sudo apt-get purge mysql-server mysql-client mysql-common
sudo apt-get autoremove
and even more commands...
But whenever I am trying to locate mysql. I get a no. of files related to mysql
command:
shell>>…
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Mysql was started:
/usr/bin/mysqld_safe --datadir=/srv/mysql/myDB --log-error=/srv/mysql/logs/mysqld-myDB.log --pid-file=/srv/mysql/pids/mysqld-myDB.pid --user=mysql --socket=/srv/mysql/sockets/mysql-myDB.sock --port=3700
but when I'm trying to do something:
ERROR 1548 (HY000) at line 1: Cannot…
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A client of my IT-consulting service owns a web-development shop. He's been having problems with a Slackware 12.0 server running MySQL 5.0.67. The machine was set up by the client's sysadmin, who left on bad terms. My client no longer employs a sysadmin.
As far as I can tell, the only copy of MySQL…
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Can't start mysql with:
sudo /usr/bin/mysqld_safe --datadir=/srv/mysql/myDB --log-error=/srv/mysql/logs/mysqld-myDB.log --pid-file=/srv/mysql/pids/mysqld-myDB.pid --user=mysql --socket=/srv/mysql/sockets/mysql-myDB.sock --port=3700
120222 13:40:48 mysqld_safe Starting mysqld daemon with databases…
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MySQL is one of the most popular database language and I have been recently working with it a lot. Data have no barrier and every database have their own place. I have been working with MySQL for quite a while and just like SQL Server, I often find lots of people asking me if I have a tutorial which…
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I've recently gotten some questions around "why do I not see a parallel plan" while Auto DOP is on (I think)...? It is probably worthwhile to quickly go over some of the ways to find out what Auto DOP was thinking. In general, there is no need to go tracing sessions and look under the hood. The thing…
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I asked PostgreSQL to explain my query. Part of the explanation was:
table_name --> Materialize
What does materialize do? I'm joining two tables, not views or anything like that.
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I have a stored procedure that I am calling using EXECUTE IMMEDIATE. The issue that I am facing is that the explain plan is different when I call the procedure directly vs when I use EXECUTE IMMEDIATE to call the procedure. This is causing the execution time to increase 5x. The main difference…
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I am making a test. I have all tests in rows, so my rows looks like this;
ID | TEST
----------------------------------
1 | 'select sysdate from dual'
2 | 'select sysdatesss from dual'
Now I read it row by row and I need to test it with EXPLAIN PLAN FOR
so the for the first row it would…
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When Oracle is estimating the 'Cost' for certain queries, does it actually look at the amount of data (rows) in a table?
For example:
If I'm doing a full table scan of employees for name='Bob', does it estimate the cost by counting the amount of existing rows, or is it always a set cost?
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