Postgres-XC tutorial PDF - PGCon
Postgres-XC tutorial PDF - PGCon
Postgres-XC tutorial PDF - PGCon
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●<br />
Perfoming JOINs on datanodes<br />
Example: Join on distribution key<br />
EXPLAIN VERBOSE SELECT * FROM tab1, tab2 WHERE tab1.val = tab2.val;<br />
QUERY PLAN<br />
<br />
Data Node Scan on "__REMOTE_FQS_QUERY__"<br />
Output: tab1.val, tab1.val2, tab2.val, tab2.val2<br />
Node/s: datanode_1<br />
Remote query: SELECT tab1.val, tab1.val2, tab2.val, tab2.val2<br />
FROM tab1, tab2 WHERE (tab1.val = tab2.val)<br />
– JOIN performed on datanode<br />
May 16th, 2012 <strong>Postgres</strong><strong>XC</strong> 57