Fixed race condition in test

dbms/tests/queries/0_stateless/00738_lock_for_inner_table.sh

@@ -9,17 +9,24 @@ DROP TABLE IF EXISTS mv;
 CREATE TABLE tab_00738(a Int) ENGINE = Log;
 CREATE MATERIALIZED VIEW mv ENGINE = Log AS SELECT a FROM tab_00738;" | ${CLICKHOUSE_CLIENT} -n
 
-${CLICKHOUSE_CLIENT} --query "INSERT INTO tab_00738 SELECT number FROM numbers(10000000)" &
+${CLICKHOUSE_CLIENT} --query_id test_00738 --query "INSERT INTO tab_00738 SELECT number FROM numbers(10000000)" &
 
 function drop()
 {
-    sleep 0.1
     ${CLICKHOUSE_CLIENT} --query "DROP TABLE \`.inner.mv\`" -n
 }
 
+function wait_for_query_to_start()
+{
+    while [[ $(${CLICKHOUSE_CLIENT} --query "SELECT count() FROM system.processes WHERE query_id = 'test_00738'") == 0 ]]; do sleep 0.001; done
+}
+
+export -f wait_for_query_to_start
+timeout 5 bash -c wait_for_query_to_start
+
 drop &
 
 wait
 
 echo "DROP TABLE IF EXISTS tab_00738;
-DROP TABLE IF EXISTS mv;" | ${CLICKHOUSE_CLIENT} -n 
+DROP TABLE IF EXISTS mv;" | ${CLICKHOUSE_CLIENT} -n