reduce workload of background barrier recovery

src/tests/simulation/tests/integration_tests/recovery/background_ddl.rs

@@ -27,6 +27,7 @@ const SET_RATE_LIMIT_2: &str = "SET STREAMING_RATE_LIMIT=2;";
 const SET_RATE_LIMIT_1: &str = "SET STREAMING_RATE_LIMIT=1;";
 const RESET_RATE_LIMIT: &str = "SET STREAMING_RATE_LIMIT=0;";
 const CREATE_MV1: &str = "CREATE MATERIALIZED VIEW mv1 as SELECT * FROM t;";
+const WAIT: &str = "WAIT;";
 
 async fn kill_cn_and_wait_recover(cluster: &Cluster) {
     // Kill it again
@@ -85,41 +86,34 @@ async fn test_background_mv_barrier_recovery() -> Result<()> {
 
     // If the CN is killed before first barrier pass for the MV, the MV will be dropped.
     // This is because it's table fragments will NOT be committed until first barrier pass.
-    sleep(Duration::from_secs(5)).await;
+    sleep(Duration::from_secs(3)).await;
     kill_cn_and_wait_recover(&cluster).await;
 
     // Send some upstream updates.
-    cluster
-        .run("INSERT INTO t1 select * from generate_series(1, 100000);")
-        .await?;
-    cluster.run("flush;").await?;
+    session.run(SEED_TABLE).await?;
+    session.flush().await?;
 
     kill_cn_and_wait_recover(&cluster).await;
     kill_and_wait_recover(&cluster).await;
 
     // Send some upstream updates.
-    cluster
-        .run("INSERT INTO t1 select * from generate_series(1, 100000);")
-        .await?;
-    cluster.run("flush;").await?;
+    session.run(SEED_TABLE).await?;
+    session.flush().await?;
 
     kill_and_wait_recover(&cluster).await;
     kill_cn_and_wait_recover(&cluster).await;
 
     // Send some upstream updates.
-    cluster
-        .run("INSERT INTO t1 select * from generate_series(1, 100000);")
-        .await?;
-    cluster.run("flush;").await?;
+    session.run(SEED_TABLE).await?;
+    session.flush().await?;
 
     // Now just wait for it to complete.
-
-    sleep(Duration::from_secs(10)).await;
+    session.run(WAIT).await?;
 
     session
         .run("SELECT COUNT(v1) FROM m1")
         .await?
-        .assert_result_eq("700000");
+        .assert_result_eq("2000");
 
     // Make sure that if MV killed and restarted
     // it will not be dropped.
@@ -180,7 +174,7 @@ async fn test_background_ddl_cancel() -> Result<()> {
     kill_and_wait_recover(&cluster).await;
 
     // Wait for job to finish
-    session.run("WAIT;").await?;
+    session.run(WAIT).await?;
 
     session.run("DROP MATERIALIZED VIEW mv1").await?;
     session.run("DROP TABLE t").await?;