Postgres-XC tutorial PDF - PGCon

General advice
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Avoid data materialization on Coordinator
postgres=# explain (costs false) select * from aa,bb where aa.a = bb.a;
QUERY PLAN
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
Data Node Scan on "__REMOTE_FQS_QUERY__"
Node/s: dn1, dn2
(2 rows)
YES !
NO !
postgres=# explain (costs false) select * from aa,bb where aa.a = bb.a;
QUERY PLAN
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
Nested Loop
Join Filter: (aa.a = bb.a)
­> Data Node Scan on aa
Node/s: dn1, dn2
­> Data Node Scan on bb
Node/s: dn1
(6 rows)
May 16th, 2012 Postgres­XC 23