Oracle 根据v$wait_chains找到造成等待的SQL

Oracle 根据v$wait_chains找到造成等待的SQL

几个视图的功能，来自官方文档
v$sqltext
V$SQLTEXT displays the text of SQL statements belonging to shared SQL cursors in the SGA.

V$SESSION
V$SESSION displays session information for each current session.

v$wait_chains
V$WAIT_CHAINS displays information about blocked sessions. A wait chain is comprised of sessions that are blocked by one another. Each row represents a blocked and blocker session pair. If a wait chain is not a cyclical wait chain, then the last row for the chain does not have a blocker.

找到造成等待的SQL

select * from v$sqltext 
    where 
        (hash_value,address) in 
    ( 
        SELECT DECODE(sql_hash_value, 0, prev_hash_value, sql_hash_value), 
            DECODE(sql_hash_value, 0, prev_sql_addr,sql_address) 
        FROM v$session 
            where sid in (select sid from v$wait_chains) 
);