-

 PROMPT [STEP 11] I/O Latency during periods this SQL appeared


COLUMN filetype_id   FORMAT 999 HEADING 'TYPE_ID'

COLUMN ms_per_read   FORMAT 999.999

COLUMN ms_per_write  FORMAT 999.999


WITH r AS (

  SELECT MIN(snap_id) b, MAX(snap_id) e

  FROM   dba_hist_sqlstat

  WHERE  sql_id='&sql_id'

)

SELECT f.filetype_id,

       ROUND(f.readtim  / DECODE(NULLIF(f.phyrds ,0),0,1,f.phyrds ),3) AS ms_per_read,

       ROUND(f.writetim / DECODE(NULLIF(f.phywrts,0),0,1,f.phywrts),3) AS ms_per_write

FROM   dba_hist_filestatxs f, r

WHERE  f.snap_id BETWEEN r.b AND r.e

GROUP  BY f.filetype_id, f.readtim, f.phyrds, f.writetim, f.phywrts

ORDER  BY ms_per_read DESC NULLS LAST;

Popular posts from this blog

-
Image
How to shutdown a Single Instance Database in Oracle 19c Overview Shutdown is an operation performed when a command is issued by the Administrator to bring down the Database or when it receives a signal to bring down the Database incase of a failure/malfunction or due to SHUTDOWN ABORT comm and execution. The options used by t he Administrator to bring down the Database is called as Shutdown Modes and the Database Server follows a sequence to shutdown a Database . Let's check how does that happen. Concepts The following are the shutdown Modes. Shutdown Modes A database administrator with SYSDBA or SYSOPER privileges can shut down the database using the SQL*Plus SHUTDOWN command or Enterprise Manager. The SHUTDOWN command has the following options that determine the shutdown behavior. Now let's look into each SHUTDOWN option in detail. SHUTDOWN ABORT  This mode is used for emergency situations, such as when shutdown with "IMMEDIATE" option doesn't work. This mode o...
Read more
-
How to startup a Single Instance Database in Oracle 19c Overview An Oracle Database goes through various stages until it is made available to the users. They are categorized into the below stages. Concepts The following are the stages of the startup sequence. Nomount   The instance is started, but is not yet associated with a database. The stages are as follows:  1. Searches for a server parameter file in a platform-specific default location and, if not found, for a text initialization parameter file (specifying STARTUP with the SPFILE or PFILE parameters overrides the default behavior)  2. Reads the parameter file to determine the values of initialization parameters  3. Allocates the SGA based on the initialization parameter settings  4. Starts the Oracle background processes  5. Opens the alert log and trace files and writes all explicit parameter settings to the alert log in valid parameter syntax At this stage, no database is associated with the instanc...
Read more