Search for SQL statements with low execution efficiency in oracle

V $ sqltext: the complete SQL statement is stored, and the SQL statement is segmented. v $ sqlarea: the stored SQL statement and related information, such as the cumulative number of executions, logical reads, statistical information such as physical reads (Statistics) v $ SQL: resolved SQL statements in the memory shared SQL area. (Instant) selectopname, target, to_char (start_time, yyyy-mm-ddhh24: m

V $ sqltext: the complete SQL statement is stored, and the SQL statement is segmented. v $ sqlarea: the stored SQL statement and related information, such as the cumulative number of executions, logical reads, statistical information such as physical reads (Statistics) v $ SQL: resolved SQL statements in the memory shared SQL area. (Instant) selectopname, target, to_char (start_time, 'yyyy-mm-ddhh24: m

V $ sqltext: complete SQL statements are stored and separated.

V $ sqlarea: the stored SQL statements and related information, such as the cumulative number of executions, logical reads, physical reads, and other statistical information (Statistics)

V $ SQL: the parsed SQL statements in the memory shared SQL area. (Instant)

Select opname, target, to_char (start_time, 'yyyy-mm-dd hh24: mi: ss') start_time, elapsed_seconds elapsed,

Executions execs, buffer_gets/decode (executions, 0, 1, executions) bufgets, module, SQL _text

From v $ session_longops sl, v $ sqlarea sa

Where sl. SQL _hash_value = sa. hash_value

And upper (substr (module, 1, 4) <> 'rman'

And substr (opname, 1, 4) <> 'rman'

And sl. start_time> trunc (sysdate)

Order by start_time;

Find the complete SQL statement based on the sid:

Select SQL _text from v $ sqltext a where a. hash_value = (select SQL _hash_value from v $ session B where B. sid = '& sid ')
Order by piece asc

Select a. CPU_TIME, -- one thousandth of CPU time (microseconds)
A. OPTIMIZER_MODE, -- Optimization Method
A. EXECUTIONS, -- number of EXECUTIONS
A. DISK_READS, -- number of disk reads
A. SHARABLE_MEM, -- the amount of memory occupied by the shared pool
A. BUFFER_GETS, -- number of times the buffer is read
A. COMMAND_TYPE, -- command type (3: select, 2: insert; 6: update; 7 delete; 47: pl/SQL program Unit)
A. SQL _TEXT, -- SQL statement
A. SHARABLE_MEM,
A. PERSISTENT_MEM,
A. RUNTIME_MEM,
A. parse_cils,
A. DISK_READS,
A. DIRECT_WRITES,
A. CONCURRENCY_WAIT_TIME,
A. USER_IO_WAIT_TIME
From SYS. V _ $ SQLAREA
WHERE PARSING_SCHEMA_NAME = 'chea _ FILL '-- tablespace
Order by a. CPU_TIME desc

Reference: http://jenniferok.iteye.com/blog/700985

Query the most resource-consuming query from V $ SQLAREA

Select B. username, a. disk_reads reads,
A.exe cutions exec, a. disk_reads/decode(a.executions,, a.exe cutions) rds_exec_ratio,
A. SQL _text Statement
From v $ sqlarea a, dba_users B
Where a. parsing_user_id = B. user_id
And a. disk_reads> 100000
Order by a. disk_reads desc;

Replace the disk_reads column with the buffer_gets column to obtain information about the SQL statements that occupy the most memory.

V $ SQL: the parsed SQL statements in the memory shared SQL area. (Instant)

List the five most frequently used queries:

Select SQL _text, executions
From (select SQL _text, executions,
Rank () over
(Order by executions desc) exec_rank
From v $ SQL)
Where exec_rank <= 5;

Top 5 SQL statements that consume the most disk reads:
Select disk_reads, SQL _text
From (select SQL _text, disk_reads,
Dense_rank () over
(Order by disk_reads desc) disk_reads_rank
From v $ SQL)
Where disk_reads_rank <= 5;

Find the query that requires a large number of buffer read (logical read) operations:

Select buffer_gets, SQL _text
From (select SQL _text, buffer_gets,
Dense_rank () over
(Order by buffer_gets desc) buffer_gets_rank
From v $ SQL)
Where buffer_gets_rank <= 5;

V $ sqlarea field definition: http://happyhou.blog.sohu.com/60494432.html

SQL_TEXT	VARCHAR2(1000)	First thousand characters of the SQL text for the current cursor
SQL_ID	VARCHAR2(13)	SQL identifier of the parent cursor in the library cache
SHARABLE_MEM	NUMBER	Amount of shared memory used by a cursor. If multiple child cursors exist, then the sum of all shared memory used by all child cursors.
PERSISTENT_MEM	NUMBER	Fixed amount of memory used for the life time of an open cursor. If multiple child cursors exist, the fixed sum of memory used for the life time of all the child cursors.
RUNTIME_MEM	NUMBER	Fixed amount of memory required during execution of a cursor. If multiple child cursors exist, the fixed sum of all memory required during execution of all the child cursors.
SORTS	NUMBER	Sum of the number of sorts that were done for all the child cursors
VERSION_COUNT	NUMBER	Number of child cursors that are present in the cache under this parent
LOADED_VERSIONS	NUMBER	Number of child cursors that are present in the cache and have their context heap (KGL heap 6) loaded
OPEN_VERSIONS	NUMBER	The number of child cursors that are currently open under this current parent
USERS_OPENING	NUMBER	Number of users that have any of the child cursors open
FETCHES	NUMBER	Number of fetches associated with the SQL statement
EXECUTIONS	NUMBER	Total number of executions, totalled over all the child cursors
END_OF_FETCH_COUNT	NUMBER	Number of times this cursor was fully executed since the cursor was brought into the library cache. the value of this statistic is not incremented when the cursor is partially executed, either because it failed during the execution or because only the first few rows produced by this cursor are fetched before the cursor is closed or re-executed. by definition, the value ofEND_OF_FETCH_COUNTColumn shoshould be less or equal to the value ofEXECUTIONSColumn.
USERS_EXECUTING	NUMBER	Total number of users executing the statement over all child cursors
LOADS	NUMBER	Number of times the object was loaded or reloaded
FIRST_LOAD_TIME	VARCHAR2(19)	Timestamp of the parent creation time
INVALIDATIONS	NUMBER	Total number of invalidations over all the child cursors
PARSE_CALLS	NUMBER	Sum of all parse callto all the child cursors under this parent
DISK_READS	NUMBER	Sum of the number of disk reads over all child cursors
DIRECT_WRITES	NUMBER	Sum of the number of direct writes over all child cursors
BUFFER_GETS	NUMBER	Sum of buffer gets over all child cursors
APPLICATION_WAIT_TIME	NUMBER	Application wait time
CONCURRENCY_WAIT_TIME	NUMBER	Concurrency wait time
CLUSTER_WAIT_TIME	NUMBER	Cluster wait time
USER_IO_WAIT_TIME	NUMBER	User I/O Wait Time
PLSQL_EXEC_TIME	NUMBER	PL/SQL execution time
JAVA_EXEC_TIME	NUMBER	Java execution time
ROWS_PROCESSED	NUMBER	Total number of rows processed on behalf of this SQL statement
COMMAND_TYPE	NUMBER	Oracle command type definition
OPTIMIZER_MODE	VARCHAR2(25)	Mode under which the SQL statement was executed
PARSING_USER_ID	NUMBER	User ID of the user that has parsed the very first cursor under this parent
PARSING_SCHEMA_ID	NUMBER	Schema ID that was used to parse this child cursor
KEPT_VERSIONS	NUMBER	Number of child cursors that have been marked to be kept usingDBMS_SHARED_POOLPackage
ADDRESS	RAW(4 | 8)	Address of the handle to the parent for this cursor
HASH_VALUE	NUMBER	Hash value of the parent statement in the library cache
OLD_HASH_VALUE	NUMBER	Old SQL hash value
MODULE	VARCHAR2(64)	Contains the name of the module that was executing at the time that the SQL statement was first parsed as set by callingDBMS_APPLICATION_INFO.SET_MODULE
MODULE_HASH	NUMBER	Hash value of the module that is named inMODULEColumn
ACTION	VARCHAR2(64)	Contains the name of the action that was executing at the time that the SQL statement was first parsed as set by callingDBMS_APPLICATION_INFO.SET_ACTION
ACTION_HASH	NUMBER	Hash value of the action that is named inACTIONColumn
SERIALIZABLE_ABORTS	NUMBER	Number of times the transaction fails to serialize, producingORA-08177Errors, totalled over all the child cursors
CPU_TIME	NUMBER	CPU time (in microseconds) used by this cursor for parsing/executing/fetching
ELAPSED_TIME	NUMBER	Elapsed time (in microseconds) used by this cursor for parsing/executing/fetching
IS_OBSOLETE	VARCHAR2(1)	Indicates whether the cursor has become obsolete (Y) Or not (N). This can happen if the number of child cursors is too large.
CHILD_LATCH	NUMBER	Child latch number that is protecting the cursor
PROGRAM_ID	NUMBER	Program identifie