Remote query
Description
If an SQL statement cannot be pushed down and a distributed execution plan cannot be generated, an execution plan for sending statements is generated. Run the EXPLAIN VERBOSE command to view the SQL statements delivered to DNs.
Typical Scenarios
If an SQL statement cannot be pushed down, a distributed execution plan cannot be generated.
Examples
-- Prepare the environment. gaussdb=# CREATE TABLE t1(c1 int,c2 int); gaussdb=# EXPLAIN VERBOSE SELECT * FROM t1 limit 1; QUERY PLAN ------------------------------------------------------------------------------------ Limit (cost=0.00..0.00 rows=1 width=8) Output: t1.c1, t1.c2 -> Data Node Scan on "__REMOTE_LIMIT_QUERY__" (cost=0.00..0.00 rows=1 width=8) Output: t1.c1, t1.c2 Node/s: All datanodes Remote query: SELECT c1, c2 FROM ONLY public.t1 WHERE true LIMIT 1::bigint (6 rows) -- Drop. gaussdb=# DROP TABLE t1;
Feedback
Was this page helpful?
Provide feedbackThank you very much for your feedback. We will continue working to improve the documentation.See the reply and handling status in My Cloud VOC.
For any further questions, feel free to contact us through the chatbot.
Chatbot