Author:     Noah Misch <noah@leadboat.com>
Commit:     Noah Misch <noah@leadboat.com>

    Set debug_query_string in worker_spi.
    
    This makes elog.c emit the string, which is good practice for a
    background worker that executes SQL strings.
    
    Reviewed by Tom Lane.
    
    Discussion: https://postgr.es/m/20201014022636.GA1962668@rfd.leadboat.com

diff --git a/src/test/modules/worker_spi/worker_spi.c b/src/test/modules/worker_spi/worker_spi.c
index 1c7b17c..258237f 100644
--- a/src/test/modules/worker_spi/worker_spi.c
+++ b/src/test/modules/worker_spi/worker_spi.c
@@ -114,53 +114,59 @@ initialize_worker_spi(worktable *table)
 	PushActiveSnapshot(GetTransactionSnapshot());
 	pgstat_report_activity(STATE_RUNNING, "initializing worker_spi schema");
 
 	/* XXX could we use CREATE SCHEMA IF NOT EXISTS? */
 	initStringInfo(&buf);
 	appendStringInfo(&buf, "select count(*) from pg_namespace where nspname = '%s'",
 					 table->schema);
 
+	debug_query_string = buf.data;
 	ret = SPI_execute(buf.data, true, 0);
 	if (ret != SPI_OK_SELECT)
 		elog(FATAL, "SPI_execute failed: error code %d", ret);
 
 	if (SPI_processed != 1)
 		elog(FATAL, "not a singleton result");
 
 	ntup = DatumGetInt64(SPI_getbinval(SPI_tuptable->vals[0],
 									   SPI_tuptable->tupdesc,
 									   1, &isnull));
 	if (isnull)
 		elog(FATAL, "null result");
 
 	if (ntup == 0)
 	{
+		debug_query_string = NULL;
 		resetStringInfo(&buf);
 		appendStringInfo(&buf,
 						 "CREATE SCHEMA \"%s\" "
 						 "CREATE TABLE \"%s\" ("
 						 "		type text CHECK (type IN ('total', 'delta')), "
 						 "		value	integer)"
 						 "CREATE UNIQUE INDEX \"%s_unique_total\" ON \"%s\" (type) "
 						 "WHERE type = 'total'",
 						 table->schema, table->name, table->name, table->name);
 
 		/* set statement start time */
 		SetCurrentStatementStartTimestamp();
 
+		debug_query_string = buf.data;
 		ret = SPI_execute(buf.data, false, 0);
 
 		if (ret != SPI_OK_UTILITY)
 			elog(FATAL, "failed to create my schema");
+
+		debug_query_string = NULL;	/* rest is not statement-specific */
 	}
 
 	SPI_finish();
 	PopActiveSnapshot();
 	CommitTransactionCommand();
+	debug_query_string = NULL;
 	pgstat_report_activity(STATE_IDLE, NULL);
 }
 
 void
 worker_spi_main(Datum main_arg)
 {
 	int			index = DatumGetInt32(main_arg);
 	worktable  *table;
@@ -257,16 +263,17 @@ worker_spi_main(Datum main_arg)
 		 *
 		 * The pgstat_report_activity() call makes our activity visible
 		 * through the pgstat views.
 		 */
 		SetCurrentStatementStartTimestamp();
 		StartTransactionCommand();
 		SPI_connect();
 		PushActiveSnapshot(GetTransactionSnapshot());
+		debug_query_string = buf.data;
 		pgstat_report_activity(STATE_RUNNING, buf.data);
 
 		/* We can now execute queries via SPI */
 		ret = SPI_execute(buf.data, false, 0);
 
 		if (ret != SPI_OK_UPDATE_RETURNING)
 			elog(FATAL, "cannot select from table %s.%s: error code %d",
 				 table->schema, table->name, ret);
@@ -286,16 +293,17 @@ worker_spi_main(Datum main_arg)
 		}
 
 		/*
 		 * And finish our transaction.
 		 */
 		SPI_finish();
 		PopActiveSnapshot();
 		CommitTransactionCommand();
+		debug_query_string = NULL;
 		pgstat_report_stat(false);
 		pgstat_report_activity(STATE_IDLE, NULL);
 	}
 
 	proc_exit(1);
 }
 
 /*