? sites/default/modules
? sites/default/settings.php
Index: includes/database/mysql/schema.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/database/mysql/schema.inc,v
retrieving revision 1.5
diff -u -p -r1.5 schema.inc
--- includes/database/mysql/schema.inc	11 Nov 2008 16:49:37 -0000	1.5
+++ includes/database/mysql/schema.inc	12 Nov 2008 14:33:05 -0000
@@ -131,6 +131,10 @@ class DatabaseSchema_mysql extends Datab
     return $field;
   }
 
+  /**
+   * This maps a generic data type in combination with its data size
+   * to the engine-specific data type.
+   */
   public function getFieldTypeMap() {
     // Put :normal last so it gets preserved by array_flip.  This makes
     // it much easier for modules (such as schema.module) to map
@@ -139,6 +143,14 @@ class DatabaseSchema_mysql extends Datab
       'varchar:normal'  => 'VARCHAR',
       'char:normal'     => 'CHAR',
 
+      // Based on maximum cross database compatibility concern, some rules
+      // for using Drupal text type:
+      // - Always assume text:big storage capacity as maximum 4000 characters
+      //   only.
+      // - Text type should function with the following SQL command:
+      //   "ORDER BY", "GROUP BY", "SELECT ... DISTINCT" and
+      //   "SELECT ... UNIQUE".
+      // - For storage capacity greater than 4000, use blob instead.
       'text:tiny'       => 'TINYTEXT',
       'text:small'      => 'TINYTEXT',
       'text:medium'     => 'MEDIUMTEXT',
@@ -165,6 +177,14 @@ class DatabaseSchema_mysql extends Datab
 
       'numeric:normal'  => 'DECIMAL',
 
+      // Based on maximum cross database compatibility concern, some rules
+      // for using Drupal blob type:
+      // - Usually support GB-scale storage capacity.
+      // - Blob type should NOT function with the following SQL command:
+      //   "ORDER BY", "GROUP BY", "SELECT ... DISTINCT" and
+      //   "SELECT ... UNIQUE".
+      // - Always utilize drupal_write_record(), db_insert(), db_update(),
+      //   db_merge() and db_delete() for blob operation.
       'blob:big'        => 'LONGBLOB',
       'blob:normal'     => 'BLOB',
 
Index: includes/database/pgsql/schema.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/database/pgsql/schema.inc,v
retrieving revision 1.2
diff -u -p -r1.2 schema.inc
--- includes/database/pgsql/schema.inc	15 Sep 2008 20:48:07 -0000	1.2
+++ includes/database/pgsql/schema.inc	12 Nov 2008 14:33:05 -0000
@@ -131,50 +131,65 @@ class DatabaseSchema_pgsql extends Datab
     return $field;
   }
 
-
   /**
    * This maps a generic data type in combination with its data size
    * to the engine-specific data type.
    */
-  function getFieldTypeMap() {
+  public function getFieldTypeMap() {
     // Put :normal last so it gets preserved by array_flip.  This makes
     // it much easier for modules (such as schema.module) to map
     // database types back into schema types.
-    $map = array(
-      'varchar:normal' => 'varchar',
-      'char:normal' => 'character',
-
-      'text:tiny' => 'text',
-      'text:small' => 'text',
-      'text:medium' => 'text',
-      'text:big' => 'text',
-      'text:normal' => 'text',
-
-      'int:tiny' => 'smallint',
-      'int:small' => 'smallint',
-      'int:medium' => 'int',
-      'int:big' => 'bigint',
-      'int:normal' => 'int',
-
-      'float:tiny' => 'real',
-      'float:small' => 'real',
-      'float:medium' => 'real',
-      'float:big' => 'double precision',
-      'float:normal' => 'real',
-
-      'numeric:normal' => 'numeric',
-
-      'blob:big' => 'bytea',
-      'blob:normal' => 'bytea',
-
-      'datetime:normal' => 'timestamp',
-
-      'serial:tiny' => 'serial',
-      'serial:small' => 'serial',
-      'serial:medium' => 'serial',
-      'serial:big' => 'bigserial',
-      'serial:normal' => 'serial',
-      );
+    static $map = array(
+      'varchar:normal'  => 'VARCHAR',
+      'char:normal'     => 'CHARACTER',
+
+      // Based on maximum cross database compatibility concern, some rules
+      // for using Drupal text type:
+      // - Always assume text:big storage capacity as maximum 4000 characters
+      //   only.
+      // - Text type should function with the following SQL command:
+      //   "ORDER BY", "GROUP BY", "SELECT ... DISTINCT" and
+      //   "SELECT ... UNIQUE".
+      // - For storage capacity greater than 4000, use blob instead.
+      'text:tiny'       => 'TEXT',
+      'text:small'      => 'TEXT',
+      'text:medium'     => 'TEXT',
+      'text:big'        => 'TEXT',
+      'text:normal'     => 'TEXT',
+
+      'serial:tiny'     => 'SERIAL',
+      'serial:small'    => 'SERIAL',
+      'serial:medium'   => 'SERIAL',
+      'serial:big'      => 'BIGSERIAL',
+      'serial:normal'   => 'SERIAL',
+
+      'int:tiny'        => 'SMALLINT',
+      'int:small'       => 'SMALLINT',
+      'int:medium'      => 'INT',
+      'int:big'         => 'BIGINT',
+      'int:normal'      => 'INT',
+
+      'float:tiny'      => 'REAL',
+      'float:small'     => 'REAL',
+      'float:medium'    => 'REAL',
+      'float:big'       => 'DOUBLE PRECISION',
+      'float:normal'    => 'REAL',
+
+      'numeric:normal'  => 'NUMERIC',
+
+      // Based on maximum cross database compatibility concern, some rules
+      // for using Drupal blob type:
+      // - Usually support GB-scale storage capacity.
+      // - Blob type should NOT function with the following SQL command:
+      //   "ORDER BY", "GROUP BY", "SELECT ... DISTINCT" and
+      //   "SELECT ... UNIQUE".
+      // - Always utilize drupal_write_record(), db_insert(), db_update(),
+      //   db_merge() and db_delete() for blob operation.
+      'blob:big'        => 'BYTEA',
+      'blob:normal'     => 'BYTEA',
+
+      'datetime:normal' => 'TIMESTAMP',
+    );
     return $map;
   }