Example:
dbadmin=> CREATE TABLE test (c1 INT, c2 VARCHAR(30), c3 INT);
CREATE TABLE
dbadmin=> EXPLAIN VERBOSE COPY test FROM '/home/dbadmin/test1.txt';
QUERY PLAN
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------
------------------------------
QUERY PLAN DESCRIPTION:
------------------------------
Opt Vertica Options
--------------------
PLAN_OUTPUT_SUPER_VERBOSE
EXPLAIN VERBOSE COPY test FROM '/home/dbadmin/test1.txt';
Access Path:
LDISTRIB_UNSEGMENTED
------------------------------
Wait, where is the plan? Oh, I need at least one table projection to get a plan!
dbadmin=> CREATE PROJECTION test_pr AS SELECT * FROM test;
CREATE PROJECTION
dbadmin=> EXPLAIN VERBOSE COPY test FROM '/home/dbadmin/test1.txt';
QUERY PLAN
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------
------------------------------
QUERY PLAN DESCRIPTION:
------------------------------
Opt Vertica Options
--------------------
PLAN_OUTPUT_SUPER_VERBOSE
EXPLAIN VERBOSE COPY test FROM '/home/dbadmin/test1.txt';
Access Path:
+-DML INSERT [Cost: 0.000000, Rows: 0.000000 Disk(B): 0.000000 CPU(B): 0.000000 Memory(B): 0.000000 Netwrk(B): 0.000000 Parallelism: 1.000000] [OutRowSz (B): 0]
| Target Projection: public.test_pr_b1 (SORT BY PROJECTION SORT ORDER) (RESEGMENT)
| Target Projection: public.test_pr_b0 (SORT BY PROJECTION SORT ORDER) (RESEGMENT)
| Target Prep:
| Execute on: Query Initiator
| LDISTRIB_UNSEGMENTED
| Execute on: Query Initiator
| LDISTRIB_UNSEGMENTED
+-LDISTRIB_UNSEGMENTED
------------------------------
Helpful Links:https://www.vertica.com/docs/latest/HTML/Content/Authoring/SQLReferenceManual/Statements/EXPLAIN.htm https://www.vertica.com/docs/latest/HTML/Content/Authoring/AdministratorsGuide/QueryManagement/QueryPlans/ExplainOutputOptions/EXPLAINOutputOptions.htm
Have fun!
About the Author
James Knicely
Vertica Field Chief Technologist
I've had the privilege of working with many database technologies in my career. But after being introduced to Vertica in May of 2011 as a client, I was hooked on the new technology after witnessing a query run in milliseconds that had previously ran for hours on the legacy database we had in place. It was then that I knew I wanted to eventually join the Vertica team, and 4 years later I did! I am currently a Vertica evangelist and am ready to help you get on board! Please feel free to reach out to me with any questions you have about Vertica and make sure to follow my Vertica Quick Tips!
