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From: Tomonari K. <kat...@po...> - 2012-08-30 10:29:48
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Hi, I'm checking behavior of Postgres-XC 1.0.0. and I have two questions. 1) pg_stat_statements when I run INSERT statement to a table with generate_series function, I can't catch the process from pg_stat_statements on Datanode. but I can catch it from pg_stat_statements on Coordinator. so I think generate_series is parsed and divided on Coordinator, and then each INSERT statement is delivered to each Datanode(this is very short time). is this right? 2) pg_locks when I run SELECT statement to a table on the first of the trunsaction, I can't catch the lock information(AccessShareLock) from pg_locks on Datanode. but I can catch it from pg_locks on Coordinator. if I run modify statement(INSERT/UPDATE/DELETE) before SELECT statement, the lock information(AccessShareLock) is appered with the SELECT statement. I think this behavior is related with virtual-transaction. and I think AccessShareLock never blocking any other queries, so this does not become any problems. is this right? System Configuration: --------------------- Architecture : x86_64 Operating Systems : CentOS release 6.2 x86_64 Postgres-XC version : Postgres-XC 1.0.0 Compilers used : gcc (GCC) 4.4.6 20110731 (Red Hat 4.4.6-3) ---- Tomonari Katsumata |