Explain SQL statements for Oracle Performance Detection

The following articles mainly talk about Oracle Performance Check SQL statements. On a website with good reputation, I found a reference to Oracle Performance Check SQL statements and related code examples, to share with you. The following is a detailed description of the article.

Oracle Performance Check SQL statements

1. Waiting for monitoring cases

 
 

  
  
select event,sum(decode(wait_Time,0,0,1)) "Prev",  
  
  
sum(decode(wait_Time,0,1,0)) "Curr",count(*) "Tot"  
  
  
from v$session_Wait  
  
  
group by event order by 4;  
 
 

2. rollback segment contention

 
 

  
  
select name, waits, gets, waits/gets "Ratio"  
  
  
from v$rollstat a, v$rollname b  
  
  
where a.usn = b.usn;  
 
 

3. Monitor the I/O ratio of tablespaces

 
 

  
  
select df.tablespace_name name,df.file_name "file",f.phyrds pyr,  
  
  
f.phyblkrd pbr,f.phywrts pyw, f.phyblkwrt pbw  
  
  
from v$filestat f, dba_data_files df  
  
  
where f.file# = df.file_id  
  
  
order by df.tablespace_name;  
 
 

4. I/O ratio of the monitored File System

 
 

  
  
select substr(a.file#,1,2) "#", substr(a.name,1,30) "Name",  
  
  
a.status, a.bytes, b.phyrds, b.phywrts  
  
  
from v$datafile a, v$filestat b  
  
  
where a.file# = b.file#;  
 
 

5. Search for all indexes under a user in Oracle Performance Detection

 
 

  
  
select user_indexes.table_name, user_indexes.index_name,
uniqueness, column_name  
  
  
from user_ind_columns, user_indexes  
  
  
where user_ind_columns.index_name = user_indexes.index_name  
  
  
and user_ind_columns.table_name = user_indexes.table_name  
  
  
order by user_indexes.table_type, user_indexes.table_name,  
  
  
user_indexes.index_name, column_position;  
 
 

6. Monitor SGA hit rate

 
 

  
  
select a.value + b.value "logical_reads", c.value "phys_reads",  
  
  
round(100 * ((a.value+b.value)-c.value) / (a.value+b.value))
 "BUFFER HIT RATIO"  
  
  
from v$sysstat a, v$sysstat b, v$sysstat c  
  
  
where a.statistic# = 38 and b.statistic# = 39  
  
  
and c.statistic# = 40;  
 
 

7. Monitor the hit rate of the Dictionary Buffer in SGA

 
 

  
  
select parameter, gets,Getmisses , getmisses/
(gets+getmisses)*100 "miss ratio",  
  
  
(1-(sum(getmisses)/ (sum(gets)+sum(getmisses))))*100 "Hit ratio"  
  
  
from v$rowcache  
  
  
where gets+getmisses <>0  
  
  
group by parameter, gets, getmisses;  
 
 

The above content is an introduction to the SQL statements used for Oracle performance testing. I hope you will find some gains.