Error Deadlock Detected
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Global Enqueue Services Deadlock Detected
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Deadlock Detected While Waiting For Resource
detected up vote 4 down vote favorite 1 Now, I'm using PostgresSQL for my database system and faced deadlock problem from PL/SQL function. Please find the SQL statement in the code block. (Just example) BEGIN UPDATE accounts SET balance = 0 WHERE acct_name like 'A%'; UPDATE accounts SET balance = balance + 100 WHERE acct_name like '%A'; EXCEPTION WHEN OTHERS THEN RAISE NOTICE SQLERRM; deadlock detected while waiting for resource oracle END; I've found that the deadlock occurred during this statement was running. But i'm not sure that there were other statements trying to update this table in the same time (Rather not cause I didn't found any statement which trying to update this table in my logging system). So, is it possible that the deadlock was occurred within this statement ? As i know, if we blocked whole statement with BEGIN/END. There will be the same transaction and should not be locked by itself. Thanks in advance, Stoper postgresql deadlock share|improve this question edited Apr 9 '12 at 18:02 Mosty Mostacho 28.5k85689 asked Apr 9 '12 at 17:55 Sathapanic Sriprom 751414 Do you have any triggers on accounts? Also do you use explicit locking? –strkol Apr 9 '12 at 18:08 By default, a transaction can observe changes committed by other transactions. For more information, see Transaction Isolation from the PostgreSQL documentation. –Joey Adams Apr 9 '12 at 18:13 @strkol Yes I have, but statement in that trigger is not related to this table. For the explicit locking is also yes. –Sathapanic Sriprom Apr 9 '12 at
deadlock error in my logs. It took me some time to figure out the exact situation that was causing this deadlock, and so I decided
Deadlock Detected Try To Fix It
to share what I've learned. What better way to do that than through deadlock detected when running 'service_update' retrying a blog. Without further ado, let's dive in. The general setting we are talking about is Java, Spring-Data, Hibernate, Postgres, though deadlock detected while waiting for resource ora-06512 the main issue is the Postgres DB. Let's start with the error. This would look something like that: ERROR: deadlock detected DETAIL: Process 552 waits for ExclusiveLock on tuple (0,3) of relation 16393 http://stackoverflow.com/questions/10077441/postgresql-deadlock-detected of database 12002; blocked by process 4924. Process 4924 waits for ShareLock on transaction 689; blocked by process 552. HINT: See server log for query details. Usually for me a deadlock error is a bad way to start the day. These are usually hard to reproduce, and not simple to solve. After reading a little about the different locks in Postgres and when they are used I http://elioxman.blogspot.com/2013/02/postgres-deadlock.html came up with the following simple scenario which reproduces this error: Given 2 tables, Parent and Child, we will try to add two children to the same parent from two different processes. After each insert we will also try to update the name of the parent. (Assume the Parent has columns: ID, Name, and the Child has columns: ID, Parent_ID, Name) Process 1: BEGIN; INSERT INTO "Child" VALUES (1, 1, 'CHILD_A'); SELECT * from pg_sleep(5); UPDATE "Parent" SET "Name"='Parent_B' WHERE "ID"=1; END; Process 2: BEGIN; INSERT INTO "Child" VALUES (2, 1, 'CHILD_B'); SELECT * from pg_sleep(5); UPDATE "Parent" SET "Name"='Parent_C' WHERE "ID"=1; END; Running these two simultaneously would result in the error above. At first it seems a little weird that this scenario gives a deadlock. I would just expect one of the processes to fail when trying to update the Parent row. The deadlock comes from the fact that when inserting a new row to the Child table, Postres acquires a RowShareLock on the Parent row (because of the foreign key). The insert from the second process also acquires a RowShareLock on the same row (acquiring two RowShareLocks is fine). When both processes come to the update statement, things
log in tour help Tour Start here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site About Us Learn more about Stack Overflow the http://dba.stackexchange.com/questions/93792/avoid-pgtrdeadlockdetected company Business Learn more about hiring developers or posting ads with us Database Administrators Questions Tags Users Badges Unanswered Ask Question _ Database Administrators Stack Exchange is a question and answer site for database professionals who wish http://support.esri.com/technical-article/000010657 to improve their database skills and learn from others in the community. Join them; it only takes a minute: Sign up Here's how it works: Anybody can ask a question Anybody can answer The best answers are deadlock detected voted up and rise to the top Avoid PG::TRDeadlockDetected up vote 0 down vote favorite I am using the below function in a bulk insert, usually the bulk insert has around 60 rows and each row will have the below function. But from time to time I get PG::TRDeadlockDetected: ERROR: deadlock detected (see the full error below). How can I avoid this? Can I add a EXCEPTION which will return 0 in case this deadlock detected while happens, I will prefer not to, but the bulk insert is very convenient for me. CREATE OR REPLACE FUNCTION "univ"."gc_title_desc"(IN _title text, IN _desc text, OUT result_id int4) RETURNS "int4" AS $BODY$BEGIN LOOP BEGIN WITH sel AS ( SELECT id FROM univ.results WHERE title = _title AND description = _desc ) , ins AS ( INSERT INTO univ.results (title, description) SELECT _title, _desc WHERE NOT EXISTS (SELECT 1 FROM sel) RETURNING id ) SELECT id FROM sel NATURAL FULL OUTER JOIN ins INTO result_id; EXCEPTION WHEN UNIQUE_VIOLATION THEN -- inserted in concurrent session. RAISE NOTICE 'It actually happened!'; -- hardly ever happens END; EXIT WHEN result_id IS NOT NULL; END LOOP; END $BODY$ LANGUAGE plpgsql COST 100 CALLED ON NULL INPUT SECURITY INVOKER VOLATILE; Error: 2015-02-25T15:11:15.078Z 3564 TID-oti3yx4ms WARN: PG::TRDeadlockDetected: ERROR: deadlock detected DETAIL: Process 15507 waits for ShareLock on transaction 14912613; blocked by process 15690. Process 15690 waits for ShareLock on transaction 14912617; blocked by process 15507. HINT: See server log for query details. CONTEXT: while inserting index tuple (12728,26) in relation "uniq_search_results_title_description" SQL statement "WITH sel AS ( SELECT id FROM univ.search_results WHERE title = _title AND description = _desc ) , ins AS ( INSERT INTO univ.search_results (title, description) SELECT _title, _desc WHERE NOT EXISTS (SELECT 1 FROM sel) RETURNING id ) SELECT id FROM sel NATURAL
Early Adopter Program ArcGIS Ideas Esri Support Services ArcGIS Blogs ArcGIS Code Sharing Product Life Cycles Manage Cases Request Case Start Chat Back to results Print Share Is This Content Helpful? Search on GeoNet Submit to ArcGIS Ideas Error: ORA-00060: deadlock detected while waiting for resource Error Message Oracle deadlocks occur when one or more sessions attempt to acquire a resource to a database object that is currently being held by a second session, which is also attempting to acquire a resource held by the first session. To break the deadlock, Oracle releases the resource being held by one session and returns an error to allow the other session to proceed. In doing so, a trace file for the offending session is created in a directory based on the value for the user_dump_dest initialization parameter.While compressing a versioned geodatabase, the compress command may potentially encounter the Oracle error "ORA-00060: deadlock detected while waiting for resource". Cause If encountering the Oracle error during a compress, the deadlock being encountered is not the customary type of deadlock where two sessions are competing/blocking requests for the same row objects to update or delete, but blocking for the ITL slots in a segment's block header.For a very detailed description of the issue, review Oracle Metalink document 62354.1 "TX Transaction locks - Example wait scenarios" under the section, "Waits due to Insufficient 'ITL' slots in a Block".The blocking condition being encountered is likely to be on either the state_lineages table or on one of its two indexes: lineages_pk or lineage__id_idx2.The error typically only manifests itself when a compress is executed while a high number of users are concurrently editing the versioned geodatabase.