71 lines
2.4 KiB
Python
71 lines
2.4 KiB
Python
#------------------------------------------------------------------------------
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# Copyright (c) 2017, 2020, Oracle and/or its affiliates. All rights reserved.
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#------------------------------------------------------------------------------
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#------------------------------------------------------------------------------
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# Threads.py
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# This script demonstrates the use of threads with cx_Oracle. A session pool
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# is used so that multiple connections are available to perform work on the
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# database. Only one operation (such as an execute or fetch) can take place at
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# a time on a connection. In the below example, one of the threads performs
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# dbms_lock.sleep while the other performs a query.
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#
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# This script requires cx_Oracle 2.5 and higher.
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#------------------------------------------------------------------------------
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import cx_Oracle
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import SampleEnv
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import threading
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pool = cx_Oracle.SessionPool(SampleEnv.GetMainUser(),
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SampleEnv.GetMainPassword(), SampleEnv.GetConnectString(), min=2,
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max=5, increment=1, threaded=True)
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# dbms_session.sleep() replaces dbms_lock.sleep() from Oracle Database 18c
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with pool.acquire() as conn:
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sleepProcName = "dbms_session.sleep" \
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if int(conn.version.split(".")[0]) >= 18 \
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else "dbms_lock.sleep"
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def TheLongQuery():
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with pool.acquire() as conn:
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cursor = conn.cursor()
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cursor.arraysize = 25000
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print("TheLongQuery(): beginning execute...")
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cursor.execute("""
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select *
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from
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TestNumbers
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cross join TestNumbers
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cross join TestNumbers
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cross join TestNumbers
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cross join TestNumbers
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cross join TestNumbers""")
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print("TheLongQuery(): done execute...")
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while True:
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rows = cursor.fetchmany()
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if not rows:
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break
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print("TheLongQuery(): fetched", len(rows), "rows...")
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print("TheLongQuery(): all done!")
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def DoALock():
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with pool.acquire() as conn:
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cursor = conn.cursor()
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print("DoALock(): beginning execute...")
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cursor.callproc(sleepProcName, (5,))
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print("DoALock(): done execute...")
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thread1 = threading.Thread(None, TheLongQuery)
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thread1.start()
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thread2 = threading.Thread(None, DoALock)
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thread2.start()
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thread1.join()
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thread2.join()
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print("All done!")
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