Increasing AR performance in connections with Oracle Follow @yiiframework

create table WWW_TAB_COLUMNS
(
  column_id    NUMBER(10) not null,
  table_name   VARCHAR2(50) not null,
  column_name  VARCHAR2(50) not null,
  data_type    VARCHAR2(100) not null,
  nullable     CHAR(1),
  data_default VARCHAR2(100),
  key          CHAR(1)
);
comment on column WWW_TAB_COLUMNS.nullable is 'Y/N';
comment on column WWW_TAB_COLUMNS.key is 'P/NULL';
alter table WWW_TAB_COLUMNS add constraint PK_WWW_TAB_COLUMNS primary
key (TABLE_NAME, COLUMN_NAME);
 
create table WWW_TABLES
(
  table_name VARCHAR2(50) not null
);
alter table WWW_TABLES add constraint PK_WWW_TABLES primary key (TABLE_NAME);
 
create table WWW_TAB_CONS
(
  table_name        VARCHAR2(50) not null,
  column_name       VARCHAR2(50) not null,
  position          NUMBER(10) not null,
  r_constraint_name VARCHAR2(50) not null,
  table_ref         VARCHAR2(50) not null,
  column_ref        VARCHAR2(200) not null
);
alter table WWW_TAB_CONS add constraint PK_WWW_TAB_CONS primary key
(TABLE_NAME, COLUMN_NAME);
alter table WWW_TAB_CONS add constraint FK_WWW_TAB_CONS foreign key
(TABLE_NAME) references WWW_TABLES (TABLE_NAME);

SELECT a.column_name, a.data_type ||
    case
        when data_precision is not null
            then '(' || a.data_precision ||
                    case when a.data_scale > 0 then ',' ||
a.data_scale else '' end
                || ')'
        when data_type = 'DATE' then ''
        else '(' || to_char(a.data_length) || ')'
    end as data_type,
    a.nullable, a.data_default,
    (   SELECT D.constraint_type
        FROM user_CONS_COLUMNS C
        inner join user_constraints D On D.constraint_name = C.constraint_name
        Where C.table_name = A.TABLE_NAME
           and C.column_name = A.column_name
           and D.constraint_type = 'P') as Key
FROM user_TAB_COLUMNS A
WHERE
    A.TABLE_NAME = 'NAZWA_TABELI'
ORDER by a.column_id

SELECT D.constraint_type, C.COLUMN_NAME, C.position, D.r_constraint_name,
                E.table_name as table_ref, f.column_name as column_ref
        FROM ALL_CONS_COLUMNS C
        inner join ALL_constraints D on D.OWNER = C.OWNER and
D.constraint_name = C.constraint_name
        left join ALL_constraints E on E.OWNER = D.r_OWNER and
E.constraint_name = D.r_constraint_name
        left join ALL_cons_columns F on F.OWNER = E.OWNER and
F.constraint_name = E.constraint_name and F.position = c.position
        WHERE C.OWNER = '{$schemaName}'
           and C.table_name = '{$name}'
           and D.constraint_type = 'R'
        order by d.constraint_name, c.position

protected function findColumns($table)
{
    list($schemaName,$tableName) = $this->getSchemaTableName($table->name);
 
 
    $sql=<<<EOD
        SELECT Upper(COLUMN_NAME) as COLUMN_NAME, Upper(DATA_TYPE) as DATA_TYPE, NULLABLE, DATA_DEFAULT, KEY
        FROM www_tab_columns
        Where Upper(table_name) = Upper('{$tableName}')
        ORDER by column_id
EOD;
 
    $command=$this->getDbConnection()->createCommand($sql);
 
    if(($columns=$command->queryAll())===array()){          
        return false;
    }
 
    foreach($columns as $column)
    {           
        $c=$this->createColumn($column);            
 
        $table->columns[$c->name]=$c;
        if($c->isPrimaryKey)
        {
            if($table->primaryKey===null)
                $table->primaryKey=$c->name;
            else if(is_string($table->primaryKey))
                $table->primaryKey=array($table->primaryKey,$c->name);
            else
                $table->primaryKey[]=$c->name;
            /*if(strpos(strtolower($column['Extra']),'auto_increment')!==false)
                $table->sequenceName='';*/
        }
    }
    return true;
}
 
protected function findConstraints($table)
{
    $sql=<<<EOD
    SELECT upper(COLUMN_NAME) As COLUMN_NAME, upper(TABLE_REF) As TABLE_REF, upper(COLUMN_REF) As COLUMN_REF
    FROM WWW_TAB_CONS
     WHERE upper(TABLE_NAME) = upper('{$table->name}')
    Order By POSITION
EOD;
    $command=$this->getDbConnection()->createCommand($sql);
    foreach($command->queryAll() as $row)
    {
        $name = $row["COLUMN_NAME"];
        $table->foreignKeys[$name]=array($row["TABLE_REF"], $row["COLUMN_REF"]);
        if(isset($table->columns[$name]))
            $table->columns[$name]->isForeignKey=true;
    }
}
 
protected function findTableNames($schema='')
{   
    $sql='SELECT upper(table_name) as TABLE_NAME FROM www_tables';
 
    $command=$this->getDbConnection()->createCommand($sql);
    $rows=$command->queryAll();
    $names=array();
    foreach($rows as $row)
    {
        $names[]=$row['TABLE_NAME'];
    }
    return $names;
}