Merge pull request #2830 from abdmaster/fix/config/database_save_queries

Added [save_queries] config in config/database.php
diff --git a/application/config/database.php b/application/config/database.php
index f0b8397..62ff3e0 100644
--- a/application/config/database.php
+++ b/application/config/database.php
@@ -65,6 +65,13 @@
 |	['autoinit'] Whether or not to automatically initialize the database.
 |	['encrypt']  Whether or not to use an encrypted connection.
 |	['compress'] Whether or not to use client compression (MySQL only)
+|	['save_queries'] TRUE/FALSE	- save all executed queries.
+|				Note: Useful for development when using with profiler. However,
+|				when too many queries run, it leads to memory exhaust. So for production
+|				mode it is better to set it FALSE. Also, if set to FALSE, the
+|				$this->db->last_query() will return FALSE. This setting can
+|				also be changed during runtime by using 
+|				$this->db->save_queries = TRUE|FALSE;
 |	['stricton'] TRUE/FALSE - forces 'Strict Mode' connections
 |							- good for ensuring strict SQL while developing
 |	['failover'] array - A array with 0 or more data for connections if the main should fail.
@@ -97,6 +104,7 @@
 	'autoinit' => TRUE,
 	'encrypt' => FALSE,
 	'compress' => FALSE,
+	'save_queries' => TRUE,
 	'stricton' => FALSE,
 	'failover' => array()
 );
diff --git a/user_guide_src/source/changelog.rst b/user_guide_src/source/changelog.rst
index 237e237..2662b45 100644
--- a/user_guide_src/source/changelog.rst
+++ b/user_guide_src/source/changelog.rst
@@ -160,6 +160,7 @@
    -  Added support for SQLite3 database driver.
    -  Added Interbase/Firebird database support via the *ibase* driver.
    -  Added ODBC support for ``create_database()``, ``drop_database()`` and ``drop_table()`` in :doc:`Database Forge <database/forge>`.
+   -  Added **save_queries** config setting in *config/database.php*. Default is ``TRUE``.
 
    -  :doc:`Query Builder <database/query_builder>` changes include: