December 2015

Full Database Caching in #Oracle 12c

If your Oracle Database fits into the buffer cache, we will put all segments into it now upon access – no more direct reads:

SQL> connect / as sysdba
Connected.
SQL> select banner from v$version;

BANNER
--------------------------------------------------------------------------------
Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production
PL/SQL Release 12.1.0.2.0 - Production
CORE	12.1.0.2.0	Production
TNS for Linux: Version 12.1.0.2.0 - Production
NLSRTL Version 12.1.0.2.0 - Production

SQL> select sum(bytes)/1024/1024 as mb from v$datafile;

	MB
----------
      1424

SQL> select current_size from v$buffer_pool;

CURRENT_SIZE
------------
	1872

The requirements are met here, I don’t need to force anything:

Don’t forget the COPY command in SQL*Plus (and SQLcl)

One of the developers asked me to copy a small table from Live to Dev. In situations like this, my first thought is to use the SQL*Plus COPY command. By the way, this command is also available in SQLcl.

It’s super-easy and has been around forever. Provided you can live with the data type restrictions, it’s a lot less hassle than expdp/impdp, even with the NETWORK_LINK option.

The twelve days of … AskTom

On the 1st day of AskTom, a poster sent to me

A question about 12c

 

On the 2nd day of AskTom, a poster sent to me

two SQL queries,

in a question about 12c

 

On the 3rd day of AskTom, a poster sent to me

three table joins,

two SQL queries,

in a question about 12c

 

On the 4th day of AskTom, a poster sent to me

four nested queries,

three table joins,

two SQL queries,

in a question about 12c

 

On the 5th day of AskTom, a poster sent to me

five pattern matches,

four nested queries,

three table joins,

two SQL queries,

in a question about 12c

 

On the 6th day of AskTom, a poster sent to me

six analytic functions,

five pattern matches,

four nested queries,

three table joins,

two SQL queries,

in a question about 12c