Proyectos de Subversion Moodle

<?php
/**
 * Library for basic performance monitoring and tuning
 *
 * This file is part of ADOdb, a Database Abstraction Layer library for PHP.
 *
 * @package ADOdb
 * @link https://adodb.org Project's web site and documentation
 * @link https://github.com/ADOdb/ADOdb Source code and issue tracker
 *
 * The ADOdb Library is dual-licensed, released under both the BSD 3-Clause
 * and the GNU Lesser General Public Licence (LGPL) v2.1 or, at your option,
 * any later version. This means you can use it in proprietary products.
 * See the LICENSE.md file distributed with this source code for details.
 * @license BSD-3-Clause
 * @license LGPL-2.1-or-later
 *
 * @copyright 2000-2013 John Lim
 * @copyright 2014 Damien Regad, Mark Newnham and the ADOdb community
 */

// security - hide paths
if (!defined('ADODB_DIR')) die();


class perf_oci8 extends adodb_perf{

        var $noShowIxora = 15; // if the sql for suspicious sql is taking too long, then disable ixora

        var $tablesSQL = "select segment_name as \"tablename\", sum(bytes)/1024 as \"size_in_k\",tablespace_name as \"tablespace\",count(*) \"extents\" from sys.user_extents
           group by segment_name,tablespace_name";

        var $version;

        var $createTableSQL = "CREATE TABLE adodb_logsql (
                  created date NOT NULL,
                  sql0 varchar(250) NOT NULL,
                  sql1 varchar(4000) NOT NULL,
                  params varchar(4000),
                  tracer varchar(4000),
                  timer decimal(16,6) NOT NULL
                )";

        var $settings = array(
        'Ratios',
                'data cache hit ratio' => array('RATIOH',
                        "select round((1-(phy.value / (cur.value + con.value)))*100,2)
                        from v\$sysstat cur, v\$sysstat con, v\$sysstat phy
                        where cur.name = 'db block gets' and
                              con.name = 'consistent gets' and
                              phy.name = 'physical reads'",
                        '=WarnCacheRatio'),

                'sql cache hit ratio' => array( 'RATIOH',
                        'select round(100*(sum(pins)-sum(reloads))/sum(pins),2)  from v$librarycache',
                        'increase <i>shared_pool_size</i> if too ratio low'),

                'datadict cache hit ratio' => array('RATIOH',
                "select
           round((1 - (sum(getmisses) / (sum(gets) +
                 sum(getmisses))))*100,2)
                from  v\$rowcache",
                'increase <i>shared_pool_size</i> if too ratio low'),

                'memory sort ratio' => array('RATIOH',
                "SELECT ROUND((100 * b.VALUE) /DECODE ((a.VALUE + b.VALUE),
       0,1,(a.VALUE + b.VALUE)),2)
FROM   v\$sysstat a,
       v\$sysstat b
WHERE  a.name = 'sorts (disk)'
AND    b.name = 'sorts (memory)'",
        "% of memory sorts compared to disk sorts - should be over 95%"),

        'IO',
                'data reads' => array('IO',
                "select value from v\$sysstat where name='physical reads'"),

        'data writes' => array('IO',
                "select value from v\$sysstat where name='physical writes'"),

        'Data Cache',

                'data cache buffers' => array( 'DATAC',
                "select a.value/b.value  from v\$parameter a, v\$parameter b
                        where a.name = 'db_cache_size' and b.name= 'db_block_size'",
                        'Number of cache buffers. Tune <i>db_cache_size</i> if the <i>data cache hit ratio</i> is too low.'),
                'data cache blocksize' => array('DATAC',
                        "select value from v\$parameter where name='db_block_size'",
                        '' ),

        'Memory Pools',
                'Mem Max Target (11g+)' => array( 'DATAC',
                "select value from v\$parameter where name = 'memory_max_target'",
                        'The memory_max_size is the maximum value to which memory_target can be set.' ),
        'Memory target (11g+)' => array( 'DATAC',
                "select value from v\$parameter where name = 'memory_target'",
                        'If memory_target is defined then SGA and PGA targets are consolidated into one memory_target.' ),
                'SGA Max Size' => array( 'DATAC',
                "select nvl(value,0)/1024.0/1024 || 'M' from v\$parameter where name = 'sga_max_size'",
                        'The sga_max_size is the maximum value to which sga_target can be set.' ),
        'SGA target' => array( 'DATAC',
                "select nvl(value,0)/1024.0/1024 || 'M'  from v\$parameter where name = 'sga_target'",
                        'If sga_target is defined then data cache, shared, java and large pool size can be 0. This is because all these pools are consolidated into one sga_target.' ),
        'PGA aggr target' => array( 'DATAC',
                "select nvl(value,0)/1024.0/1024 || 'M' from v\$parameter where name = 'pga_aggregate_target'",
                        'If pga_aggregate_target is defined then this is the maximum memory that can be allocated for cursor operations such as sorts, group by, joins, merges. When in doubt, set it to 20% of sga_target.' ),
        'data cache size' => array('DATAC',
                        "select value from v\$parameter where name = 'db_cache_size'",
                        'db_cache_size' ),
                'shared pool size' => array('DATAC',
                        "select value from v\$parameter where name = 'shared_pool_size'",
                        'shared_pool_size, which holds shared sql, stored procedures, dict cache and similar shared structs' ),
                'java pool size' => array('DATAJ',
                        "select value from v\$parameter where name = 'java_pool_size'",
                        'java_pool_size' ),
                'large pool buffer size' => array('CACHE',
                        "select value from v\$parameter where name='large_pool_size'",
                        'this pool is for large mem allocations (not because it is larger than shared pool), for MTS sessions, parallel queries, io buffers (large_pool_size) ' ),

                'dynamic memory usage' => array('CACHE', "select '-' from dual", '=DynMemoryUsage'),

                'Connections',
                'current connections' => array('SESS',
                        'select count(*) from sys.v_$session where username is not null',
                        ''),
                'max connections' => array( 'SESS',
                        "select value from v\$parameter where name='sessions'",
                        ''),

        'Memory Utilization',
                'data cache utilization ratio' => array('RATIOU',
                        "select round((1-bytes/sgasize)*100, 2)
                        from (select sum(bytes) sgasize from sys.v_\$sgastat) s, sys.v_\$sgastat f
                        where name = 'free memory' and pool = 'shared pool'",
                'Percentage of data cache actually in use - should be over 85%'),

                'shared pool utilization ratio' => array('RATIOU',
                'select round((sga.bytes/case when p.value=0 then sga.bytes else to_number(p.value) end)*100,2)
                from v$sgastat sga, v$parameter p
                where sga.name = \'free memory\' and sga.pool = \'shared pool\'
                and p.name = \'shared_pool_size\'',
                'Percentage of shared pool actually used - too low is bad, too high is worse'),

                'large pool utilization ratio' => array('RATIOU',
                        "select round((1-bytes/sgasize)*100, 2)
                        from (select sum(bytes) sgasize from sys.v_\$sgastat) s, sys.v_\$sgastat f
                        where name = 'free memory' and pool = 'large pool'",
                'Percentage of large_pool actually in use - too low is bad, too high is worse'),
                'sort buffer size' => array('CACHE',
                        "select value from v\$parameter where name='sort_area_size'",
                        'max in-mem sort_area_size (per query), uses memory in pga' ),

                /*'pga usage at peak' => array('RATIOU',
                '=PGA','Mb utilization at peak transactions (requires Oracle 9i+)'),*/
        'Transactions',
                'rollback segments' => array('ROLLBACK',
                        "select count(*) from sys.v_\$rollstat",
                        ''),

                'peak transactions' => array('ROLLBACK',
                        "select max_utilization  tx_hwm
                from sys.v_\$resource_limit
                where resource_name = 'transactions'",
                        'Taken from high-water-mark'),
                'max transactions' => array('ROLLBACK',
                        "select value from v\$parameter where name = 'transactions'",
                        'max transactions / rollback segments < 3.5 (or transactions_per_rollback_segment)'),
        'Parameters',
                'cursor sharing' => array('CURSOR',
                        "select value from v\$parameter where name = 'cursor_sharing'",
                        'Cursor reuse strategy. Recommended is FORCE (8i+) or SIMILAR (9i+). See <a href=http://www.praetoriate.com/oracle_tips_cursor_sharing.htm>cursor_sharing</a>.'),
                /*
                'cursor reuse' => array('CURSOR',
                        "select count(*) from (select sql_text_wo_constants, count(*)
  from t1
 group by sql_text_wo_constants
having count(*) > 100)",'These are sql statements that should be using bind variables'),*/
                'index cache cost' => array('COST',
                        "select value from v\$parameter where name = 'optimizer_index_caching'",
                        '=WarnIndexCost'),
                'random page cost' => array('COST',
                        "select value from v\$parameter where name = 'optimizer_index_cost_adj'",
                        '=WarnPageCost'),
        'Waits',
                'Recent wait events' => array('WAITS','select \'Top 5 events\' from dual','=TopRecentWaits'),
//              'Historical wait SQL' => array('WAITS','select \'Last 2 days\' from dual','=TopHistoricalWaits'), -- requires AWR license
        'Backup',
                'Achivelog Mode' => array('BACKUP', 'select log_mode from v$database', '=LogMode'),

                'DBID' => array('BACKUP','select dbid from v$database','Primary key of database, used for recovery with an RMAN Recovery Catalog'),
                'Archive Log Dest' => array('BACKUP', "SELECT NVL(v1.value,v2.value)
FROM v\$parameter v1, v\$parameter v2 WHERE v1.name='log_archive_dest' AND v2.name='log_archive_dest_10'", ''),

                'Flashback Area' => array('BACKUP', "select nvl(value,'Flashback Area not used') from v\$parameter where name=lower('DB_RECOVERY_FILE_DEST')", 'Flashback area is a folder where all backup data and logs can be stored and managed by Oracle. If Error: message displayed, then it is not in use.'),

                'Flashback Usage' => array('BACKUP', "select nvl('-','Flashback Area not used') from v\$parameter where name=lower('DB_RECOVERY_FILE_DEST')", '=FlashUsage', 'Flashback area usage.'),

                'Control File Keep Time' => array('BACKUP', "select value from v\$parameter where name='control_file_record_keep_time'",'No of days to keep RMAN info in control file.  Recommended set to x2 or x3 times the frequency of your full backup.'),
                'Recent RMAN Jobs' => array('BACKUP', "select '-' from dual", "=RMAN"),

                //              'Control File Keep Time' => array('BACKUP', "select value from v\$parameter where name='control_file_record_keep_time'",'No of days to keep RMAN info in control file. I recommend it be set to x2 or x3 times the frequency of your full backup.'),
      'Storage', 'Tablespaces' => array('TABLESPACE', "select '-' from dual", "=TableSpace"),
                false

        );


        function __construct(&$conn)
        {
        global $gSQLBlockRows;

                $gSQLBlockRows = 1000;
                $savelog = $conn->LogSQL(false);
                $this->version = $conn->ServerInfo();
                $conn->LogSQL($savelog);
                $this->conn = $conn;
        }

        function LogMode()
        {
                $mode = $this->conn->GetOne("select log_mode from v\$database");

                if ($mode == 'ARCHIVELOG') return 'To turn off archivelog:<br>
        <pre><font size=-2>
        SQLPLUS> connect sys as sysdba;
        SQLPLUS> shutdown immediate;

        SQLPLUS> startup mount exclusive;
        SQLPLUS> alter database noarchivelog;
        SQLPLUS> alter database open;
</font></pre>';

                return 'To turn on archivelog:<br>
        <pre><font size=-2>
        SQLPLUS> connect sys as sysdba;
        SQLPLUS> shutdown immediate;

        SQLPLUS> startup mount exclusive;
        SQLPLUS> alter database archivelog;
        SQLPLUS> archive log start;
        SQLPLUS> alter database open;
</font></pre>';
        }

        function TopRecentWaits()
        {

                $rs = $this->conn->Execute("select * from (
                select event, round(100*time_waited/(select sum(time_waited) from v\$system_event where wait_class <> 'Idle'),1) \"% Wait\",
    total_waits,time_waited, average_wait,wait_class from v\$system_event where wait_class <> 'Idle' order by 2 desc
        ) where rownum <=5");

                $ret = rs2html($rs,false,false,false,false);
                return "&nbsp;<p>".$ret."&nbsp;</p>";

        }

        function TopHistoricalWaits()
        {
                $days = 2;

                $rs = $this->conn->Execute("select * from (   SELECT
         b.wait_class,B.NAME,
        round(sum(wait_time+TIME_WAITED)/1000000) waitsecs,
        parsing_schema_name,
        C.SQL_TEXT, a.sql_id
FROM    V\$ACTIVE_SESSION_HISTORY A
        join V\$EVENT_NAME B  on  A.EVENT# = B.EVENT#
       join V\$SQLAREA C  on  A.SQL_ID = C.SQL_ID
WHERE   A.SAMPLE_TIME BETWEEN sysdate-$days and sysdate
       and parsing_schema_name not in ('SYS','SYSMAN','DBSNMP','SYSTEM')
GROUP BY b.wait_class,parsing_schema_name,C.SQL_TEXT, B.NAME,A.sql_id
order by 3 desc) where rownum <=10");

                $ret = rs2html($rs,false,false,false,false);
                return "&nbsp;<p>".$ret."&nbsp;</p>";

        }

        function TableSpace()
        {

                $rs = $this->conn->Execute(
        "select tablespace_name,round(sum(bytes)/1024/1024) as Used_MB,round(sum(maxbytes)/1024/1024) as Max_MB, round(sum(bytes)/sum(maxbytes),4) * 100 as PCT
        from dba_data_files
   group by tablespace_name order by 2 desc");

                $ret = "<p><b>Tablespace</b>".rs2html($rs,false,false,false,false);

                $rs = $this->conn->Execute("select * from dba_data_files order by tablespace_name, 1");
                $ret .= "<p><b>Datafile</b>".rs2html($rs,false,false,false,false);

                return "&nbsp;<p>".$ret."&nbsp;</p>";
        }

        function RMAN()
        {
                $rs = $this->conn->Execute("select * from (select start_time, end_time, operation, status, mbytes_processed, output_device_type
                        from V\$RMAN_STATUS order by start_time desc) where rownum <=10");

                $ret = rs2html($rs,false,false,false,false);
                return "&nbsp;<p>".$ret."&nbsp;</p>";

        }

        function DynMemoryUsage()
        {
                if (@$this->version['version'] >= 11) {
                        $rs = $this->conn->Execute("select component, current_size/1024./1024 as \"CurrSize (M)\" from  V\$MEMORY_DYNAMIC_COMPONENTS");

                } else
                        $rs = $this->conn->Execute("select name, round(bytes/1024./1024,2) as \"CurrSize (M)\" from  V\$sgainfo");


                $ret = rs2html($rs,false,false,false,false);
                return "&nbsp;<p>".$ret."&nbsp;</p>";
        }

        function FlashUsage()
        {
        $rs = $this->conn->Execute("select * from  V\$FLASH_RECOVERY_AREA_USAGE");
                $ret = rs2html($rs,false,false,false,false);
                return "&nbsp;<p>".$ret."&nbsp;</p>";
        }

        function WarnPageCost($val)
        {
                if ($val == 100 && $this->version['version'] < 10) $s = '<font color=red><b>Too High</b>. </font>';
                else $s = '';

                return $s.'Recommended is 20-50 for TP, and 50 for data warehouses. Default is 100. See <a href=http://www.dba-oracle.com/oracle_tips_cost_adj.htm>optimizer_index_cost_adj</a>. ';
        }

        function WarnIndexCost($val)
        {
                if ($val == 0 && $this->version['version'] < 10) $s = '<font color=red><b>Too Low</b>. </font>';
                else $s = '';

                return $s.'Percentage of indexed data blocks expected in the cache.
                        Recommended is 20 (fast disk array) to 30 (slower hard disks). Default is 0.
                         See <a href=http://www.dba-oracle.com/oracle_tips_cbo_part1.htm>optimizer_index_caching</a>.';
                }

        function PGA()
        {

                //if ($this->version['version'] < 9) return 'Oracle 9i or later required';
        }

        function PGA_Advice()
        {
                $t = "<h3>PGA Advice Estimate</h3>";
                if ($this->version['version'] < 9) return $t.'Oracle 9i or later required';

                $rs = $this->conn->Execute('select a.MB,
                        case when a.targ = 1 then \'<<= Current \'
                        when a.targ < 1  or a.pct <= b.pct then null
                        else
                        \'- BETTER than Current by \'||round(a.pct/b.pct*100-100,2)||\'%\' end as "Percent Improved",
        a.targ as  "PGA Size Factor",a.pct "% Perf"
        from
       (select round(pga_target_for_estimate/1024.0/1024.0,0) MB,
              pga_target_factor targ,estd_pga_cache_hit_percentage pct,rownum as r
              from v$pga_target_advice) a left join
       (select round(pga_target_for_estimate/1024.0/1024.0,0) MB,
              pga_target_factor targ,estd_pga_cache_hit_percentage pct,rownum as r
              from v$pga_target_advice) b on
      a.r = b.r+1 where
          b.pct < 100');
                if (!$rs) return $t."Only in 9i or later";
        //      $rs->Close();
                if ($rs->EOF) return $t."PGA could be too big";

                return $t.rs2html($rs,false,false,true,false);
        }

        function Explain($sql,$partial=false)
        {
                $savelog = $this->conn->LogSQL(false);
                $rs = $this->conn->SelectLimit("select ID FROM PLAN_TABLE");
                if (!$rs) {
                        echo "<p><b>Missing PLAN_TABLE</b></p>
<pre>
CREATE TABLE PLAN_TABLE (
  STATEMENT_ID                    VARCHAR2(30),
  TIMESTAMP                       DATE,
  REMARKS                         VARCHAR2(80),
  OPERATION                       VARCHAR2(30),
  OPTIONS                         VARCHAR2(30),
  OBJECT_NODE                     VARCHAR2(128),
  OBJECT_OWNER                    VARCHAR2(30),
  OBJECT_NAME                     VARCHAR2(30),
  OBJECT_INSTANCE                 NUMBER(38),
  OBJECT_TYPE                     VARCHAR2(30),
  OPTIMIZER                       VARCHAR2(255),
  SEARCH_COLUMNS                  NUMBER,
  ID                              NUMBER(38),
  PARENT_ID                       NUMBER(38),
  POSITION                        NUMBER(38),
  COST                            NUMBER(38),
  CARDINALITY                     NUMBER(38),
  BYTES                           NUMBER(38),
  OTHER_TAG                       VARCHAR2(255),
  PARTITION_START                 VARCHAR2(255),
  PARTITION_STOP                  VARCHAR2(255),
  PARTITION_ID                    NUMBER(38),
  OTHER                           LONG,
  DISTRIBUTION                    VARCHAR2(30)
);
</pre>";
                        return false;
                }

                $rs->Close();
        //      $this->conn->debug=1;

                if ($partial) {
                        $sqlq = $this->conn->qstr($sql.'%');
                        $arr = $this->conn->GetArray("select distinct sql1 from adodb_logsql where sql1 like $sqlq");
                        if ($arr) {
                                foreach($arr as $row) {
                                        $sql = reset($row);
                                        if (crc32($sql) == $partial) break;
                                }
                        }
                }

                $s = "<p><b>Explain</b>: ".htmlspecialchars($sql)."</p>";

                $this->conn->BeginTrans();
                $id = "ADODB ".microtime();

                $rs = $this->conn->Execute("EXPLAIN PLAN SET STATEMENT_ID='$id' FOR $sql");
                $m = $this->conn->ErrorMsg();
                if ($m) {
                        $this->conn->RollbackTrans();
                        $this->conn->LogSQL($savelog);
                        $s .= "<p>$m</p>";
                        return $s;
                }
                $rs = $this->conn->Execute("
                select
  '<pre>'||lpad('--', (level-1)*2,'-') || trim(operation) || ' ' || trim(options)||'</pre>'  as Operation,
  object_name,COST,CARDINALITY,bytes
                FROM plan_table
START WITH id = 0  and STATEMENT_ID='$id'
CONNECT BY prior id=parent_id and statement_id='$id'");

                $s .= rs2html($rs,false,false,false,false);
                $this->conn->RollbackTrans();
                $this->conn->LogSQL($savelog);
                $s .= $this->Tracer($sql,$partial);
                return $s;
        }

        function CheckMemory()
        {
                if ($this->version['version'] < 9) return 'Oracle 9i or later required';

                 $rs = $this->conn->Execute("
select  a.name Buffer_Pool, b.size_for_estimate as cache_mb_estimate,
        case when b.size_factor=1 then
                '&lt;&lt;= Current'
         when a.estd_physical_read_factor-b.estd_physical_read_factor > 0.001 and b.estd_physical_read_factor<1 then
                '- BETTER than current by ' || round((1-b.estd_physical_read_factor)/b.estd_physical_read_factor*100,2) || '%'
        else ' ' end as RATING,
   b.estd_physical_read_factor \"Phys. Reads Factor\",
   round((a.estd_physical_read_factor-b.estd_physical_read_factor)/b.estd_physical_read_factor*100,2) as \"% Improve\"
   from (select size_for_estimate,size_factor,estd_physical_read_factor,rownum  r,name from v\$db_cache_advice order by name,1) a ,
   (select size_for_estimate,size_factor,estd_physical_read_factor,rownum r,name from v\$db_cache_advice order by name,1) b
   where a.r = b.r-1 and a.name = b.name
  ");
                if (!$rs) return false;

                /*
                The v$db_cache_advice utility show the marginal changes in physical data block reads for different sizes of db_cache_size
                */
                $s = "<h3>Data Cache Advice Estimate</h3>";
                if ($rs->EOF) {
                        $s .= "<p>Cache that is 50% of current size is still too big</p>";
                } else {
                        $s .= "Ideal size of Data Cache is when %BETTER gets close to zero.";
                        $s .= rs2html($rs,false,false,false,false);
                }
                return $s.$this->PGA_Advice();
        }

        /*
                Generate html for suspicious/expensive sql
        */
        function tohtml(&$rs,$type)
        {
                $o1 = $rs->FetchField(0);
                $o2 = $rs->FetchField(1);
                $o3 = $rs->FetchField(2);
                if ($rs->EOF) return '<p>None found</p>';
                $check = '';
                $sql = '';
                $s = "\n\n<table border=1 bgcolor=white><tr><td><b>".$o1->name.'</b></td><td><b>'.$o2->name.'</b></td><td><b>'.$o3->name.'</b></td></tr>';
                while (!$rs->EOF) {
                        if ($check != $rs->fields[0].'::'.$rs->fields[1]) {
                                if ($check) {
                                        $carr = explode('::',$check);
                                        $prefix = "<a href=\"?$type=1&sql=".rawurlencode($sql).'&x#explain">';
                                        $suffix = '</a>';
                                        if (strlen($prefix)>2000) {
                                                $prefix = '';
                                                $suffix = '';
                                        }

                                        $s .=  "\n<tr><td align=right>".$carr[0].'</td><td align=right>'.$carr[1].'</td><td>'.$prefix.$sql.$suffix.'</td></tr>';
                                }
                                $sql = $rs->fields[2];
                                $check = $rs->fields[0].'::'.$rs->fields[1];
                        } else
                                $sql .= $rs->fields[2];
                        if (substr($sql,strlen($sql)-1) == "\0") $sql = substr($sql,0,strlen($sql)-1);
                        $rs->MoveNext();
                }
                $rs->Close();

                $carr = explode('::',$check);
                $prefix = "<a target=".rand()." href=\"?&hidem=1&$type=1&sql=".rawurlencode($sql).'&x#explain">';
                $suffix = '</a>';
                if (strlen($prefix)>2000) {
                        $prefix = '';
                        $suffix = '';
                }
                $s .=  "\n<tr><td align=right>".$carr[0].'</td><td align=right>'.$carr[1].'</td><td>'.$prefix.$sql.$suffix.'</td></tr>';

                return $s."</table>\n\n";
        }

        // code thanks to Ixora.
        // http://www.ixora.com.au/scripts/query_opt.htm
        // requires oracle 8.1.7 or later
        function SuspiciousSQL($numsql=10)
        {
                $sql = "
select
  substr(to_char(s.pct, '99.00'), 2) || '%'  load,
  s.executions  executes,
  p.sql_text
from
  (
    select
      address,
      buffer_gets,
      executions,
      pct,
      rank() over (order by buffer_gets desc)  ranking
    from
      (
        select
          address,
          buffer_gets,
          executions,
          100 * ratio_to_report(buffer_gets) over ()  pct
        from
          sys.v_\$sql
        where
          command_type != 47 and module != 'T.O.A.D.'
      )
    where
      buffer_gets > 50 * executions
  )  s,
  sys.v_\$sqltext  p
where
  s.ranking <= $numsql and
  p.address = s.address
order by
  1 desc, s.address, p.piece";

                global $ADODB_CACHE_MODE;
                if (isset($_GET['expsixora']) && isset($_GET['sql'])) {
                                $partial = empty($_GET['part']);
                                echo "<a name=explain></a>".$this->Explain($_GET['sql'],$partial)."\n";
                }

                if (isset($_GET['sql'])) return $this->_SuspiciousSQL($numsql);

                $s = '';
                $timer = time();
                $s .= $this->_SuspiciousSQL($numsql);
                $timer = time() - $timer;

                if ($timer > $this->noShowIxora) return $s;
                $s .= '<p>';

                $save = $ADODB_CACHE_MODE;
                $ADODB_CACHE_MODE = ADODB_FETCH_NUM;
                if ($this->conn->fetchMode !== false) $savem = $this->conn->SetFetchMode(false);

                $savelog = $this->conn->LogSQL(false);
                $rs = $this->conn->SelectLimit($sql);
                $this->conn->LogSQL($savelog);

                if (isset($savem)) $this->conn->SetFetchMode($savem);
                $ADODB_CACHE_MODE = $save;
                if ($rs) {
                        $s .= "\n<h3>Ixora Suspicious SQL</h3>";
                        $s .= $this->tohtml($rs,'expsixora');
                }

                return $s;
        }

        // code thanks to Ixora.
        // http://www.ixora.com.au/scripts/query_opt.htm
        // requires oracle 8.1.7 or later
        function ExpensiveSQL($numsql = 10)
        {
                $sql = "
select
  substr(to_char(s.pct, '99.00'), 2) || '%'  load,
  s.executions  executes,
  p.sql_text
from
  (
    select
      address,
      disk_reads,
      executions,
      pct,
      rank() over (order by disk_reads desc)  ranking
    from
      (
        select
          address,
          disk_reads,
          executions,
          100 * ratio_to_report(disk_reads) over ()  pct
        from
          sys.v_\$sql
        where
          command_type != 47 and module != 'T.O.A.D.'
      )
    where
      disk_reads > 50 * executions
  )  s,
  sys.v_\$sqltext  p
where
  s.ranking <= $numsql and
  p.address = s.address
order by
  1 desc, s.address, p.piece
";
                global $ADODB_CACHE_MODE;
                if (isset($_GET['expeixora']) && isset($_GET['sql'])) {
                        $partial = empty($_GET['part']);
                        echo "<a name=explain></a>".$this->Explain($_GET['sql'],$partial)."\n";
                }
                if (isset($_GET['sql'])) {
                         $var = $this->_ExpensiveSQL($numsql);
                         return $var;
                }

                $s = '';
                $timer = time();
                $s .= $this->_ExpensiveSQL($numsql);
                $timer = time() - $timer;
                if ($timer > $this->noShowIxora) return $s;

                $s .= '<p>';
                $save = $ADODB_CACHE_MODE;
                $ADODB_CACHE_MODE = ADODB_FETCH_NUM;
                if ($this->conn->fetchMode !== false) $savem = $this->conn->SetFetchMode(false);

                $savelog = $this->conn->LogSQL(false);
                $rs = $this->conn->Execute($sql);
                $this->conn->LogSQL($savelog);

                if (isset($savem)) $this->conn->SetFetchMode($savem);
                $ADODB_CACHE_MODE = $save;

                if ($rs) {
                        $s .= "\n<h3>Ixora Expensive SQL</h3>";
                        $s .= $this->tohtml($rs,'expeixora');
                }

                return $s;
        }

        function clearsql()
        {
                $perf_table = adodb_perf::table();
        // using the naive "delete from $perf_table where created<".$this->conn->sysTimeStamp will cause the table to lock, possibly
        // for a long time
                $sql =
"DECLARE cnt pls_integer;
BEGIN
        cnt := 0;
        FOR rec IN (SELECT ROWID AS rr FROM $perf_table WHERE created<SYSDATE)
        LOOP
          cnt := cnt + 1;
          DELETE FROM $perf_table WHERE ROWID=rec.rr;
          IF cnt = 1000 THEN
                COMMIT;
                cnt := 0;
          END IF;
        END LOOP;
        commit;
END;";

                $ok = $this->conn->Execute($sql);
        }

}