Fix gp_max_csv_line_length does not work in INSERT INTO ... SELECT ...

gp_max_csv_line_length is a session level GUC. When change it in
session, it affects statement like select * from <external_table>.
But it does not work for INSERT INTO table SELECT * FROM <external_table>.
For such statement, the scan of external table happens in a QE backend
process, not the QD.
This fix add GUC_GPDB_ADDOPT so that setting this GUC in session level
can affect both QD and QE process.

src/backend/utils/misc/guc_gp.c

@@ -3639,6 +3639,7 @@ struct config_int ConfigureNamesInt_gp[] =
 		{"gp_max_csv_line_length", PGC_USERSET, EXTERNAL_TABLES,
 			gettext_noop("Maximum allowed length of a csv input data row in bytes"),
 			NULL,
+			GUC_GPDB_ADDOPT
 		},
 		&gp_max_csv_line_length,
 		1 * 1024 * 1024, 32 * 1024, 4 * 1024 * 1024, NULL, NULL

src/test/regress/input/external_table.source

@@ -1574,3 +1574,32 @@ SET gp_log_gang TO DEFAULT;
 
 DROP FUNCTION exttab_error_context_callback_func();
 DROP EXTERNAL TABLE exttab_error_context_callback;
+
+-- --------------------------------------
+-- gp_max_csv_line_length
+-- --------------------------------------
+CREATE EXTERNAL TABLE gp_max_csv_line_length_issue (word text)
+LOCATION ('file://@hostname@/tmp/long_text.csv')
+FORMAT 'CSV';
+
+CREATE TABLE gp_max_csv_line_length_target (word text);
+
+-- generate a csv with single line > 3MB with line breaks
+COPY (
+  SELECT array_to_string(ARRAY(
+    SELECT array_to_string(ARRAY(
+      SELECT chr((65 + round(random() * 25)) :: integer)
+      FROM generate_series(1, 1023)
+    ), '') || chr(10)
+  FROM generate_series(1, 3*1024+512)), '')
+) TO '/tmp/long_text.csv' WITH CSV;
+
+-- This will fail as data too long
+INSERT INTO gp_max_csv_line_length_target SELECT * FROM gp_max_csv_line_length_issue;
+
+SET gp_max_csv_line_length TO 4194304;
+-- This should pass the gp_max_csv_line_length
+INSERT INTO gp_max_csv_line_length_target SELECT * FROM gp_max_csv_line_length_issue;
+
+DROP TABLE gp_max_csv_line_length_target;
+DROP EXTERNAL TABLE gp_max_csv_line_length_issue;

src/test/regress/output/external_table.source

@@ -2971,3 +2971,30 @@ CONTEXT:  PL/pgSQL function "exttab_error_context_callback_func" line 4 at FOR o
 SET gp_log_gang TO DEFAULT;
 DROP FUNCTION exttab_error_context_callback_func();
 DROP EXTERNAL TABLE exttab_error_context_callback;
+-- --------------------------------------
+-- gp_max_csv_line_length
+-- --------------------------------------
+CREATE EXTERNAL TABLE gp_max_csv_line_length_issue (word text)
+LOCATION ('file://@hostname@/tmp/long_text.csv')
+FORMAT 'CSV';
+CREATE TABLE gp_max_csv_line_length_target (word text);
+NOTICE:  Table doesn't have 'DISTRIBUTED BY' clause -- Using column named 'word' as the Greenplum Database data distribution key for this table.
+HINT:  The 'DISTRIBUTED BY' clause determines the distribution of data. Make sure column(s) chosen are the optimal data distribution key to minimize skew.
+-- generate a csv with single line > 3MB with line breaks
+COPY (
+  SELECT array_to_string(ARRAY(
+    SELECT array_to_string(ARRAY(
+      SELECT chr((65 + round(random() * 25)) :: integer)
+      FROM generate_series(1, 1023)
+    ), '') || chr(10)
+  FROM generate_series(1, 3*1024+512)), '')
+) TO '/tmp/long_text.csv' WITH CSV;
+-- This will fail as data too long
+INSERT INTO gp_max_csv_line_length_target SELECT * FROM gp_max_csv_line_length_issue;
+ERROR:  data line too long. likely due to invalid csv data  (seg0 slice1 @hostname@:25432 pid=2592)
+DETAIL:  External table gp_max_csv_line_length_issue, line 1024 of file file://@hostname@/tmp/long_text.csv
+SET gp_max_csv_line_length TO 4194304;
+-- This should pass the gp_max_csv_line_length
+INSERT INTO gp_max_csv_line_length_target SELECT * FROM gp_max_csv_line_length_issue;
+DROP TABLE gp_max_csv_line_length_target;
+DROP EXTERNAL TABLE gp_max_csv_line_length_issue;