From bb72a84647e7ba252cab010e65d14835b05e1834 Mon Sep 17 00:00:00 2001
From: Dennis Zhuang <killme2008@gmail.com>
Date: Wed, 10 Jan 2024 18:28:03 +0800
Subject: [PATCH] feat: adds timestamp column

---
 .../src/information_schema/runtime_metrics.rs | 25 ++++++++++++++++---
 .../common/system/information_schema.result   | 19 +++++++-------
 2 files changed, 32 insertions(+), 12 deletions(-)

diff --git a/src/catalog/src/information_schema/runtime_metrics.rs b/src/catalog/src/information_schema/runtime_metrics.rs
index 14ee93544ccb..52233db39111 100644
--- a/src/catalog/src/information_schema/runtime_metrics.rs
+++ b/src/catalog/src/information_schema/runtime_metrics.rs
@@ -20,6 +20,7 @@ use common_error::ext::BoxedError;
 use common_query::physical_plan::TaskContext;
 use common_recordbatch::adapter::RecordBatchStreamAdapter;
 use common_recordbatch::{RecordBatch, SendableRecordBatchStream};
+use common_time::util::current_time_millis;
 use datafusion::physical_plan::stream::RecordBatchStreamAdapter as DfRecordBatchStreamAdapter;
 use datafusion::physical_plan::streaming::PartitionStream as DfPartitionStream;
 use datafusion::physical_plan::SendableRecordBatchStream as DfSendableRecordBatchStream;
@@ -27,7 +28,8 @@ use datatypes::prelude::{ConcreteDataType, MutableVector};
 use datatypes::scalars::ScalarVectorBuilder;
 use datatypes::schema::{ColumnSchema, Schema, SchemaRef};
 use datatypes::vectors::{
-    ConstantVector, Float64VectorBuilder, StringVector, StringVectorBuilder, VectorRef,
+    ConstantVector, Float64VectorBuilder, StringVector, StringVectorBuilder,
+    TimestampMillisecondVector, VectorRef,
 };
 use itertools::Itertools;
 use snafu::ResultExt;
@@ -45,6 +47,7 @@ const METRIC_VALUE: &str = "value";
 const METRIC_LABELS: &str = "labels";
 const NODE: &str = "node";
 const NODE_TYPE: &str = "node_type";
+const TIMESTAMP: &str = "timestamp";
 
 /// The `information_schema.runtime_metrics` virtual table.
 /// It provides the GreptimeDB runtime metrics for the users by SQL.
@@ -62,6 +65,11 @@ impl InformationSchemaMetrics {
             ColumnSchema::new(METRIC_LABELS, ConcreteDataType::string_datatype(), true),
             ColumnSchema::new(NODE, ConcreteDataType::string_datatype(), false),
             ColumnSchema::new(NODE_TYPE, ConcreteDataType::string_datatype(), false),
+            ColumnSchema::new(
+                TIMESTAMP,
+                ConcreteDataType::timestamp_millisecond_datatype(),
+                false,
+            ),
         ]))
     }
 
@@ -169,8 +177,17 @@ impl InformationSchemaMetricsBuilder {
     }
 
     fn finish(&mut self) -> Result<RecordBatch> {
-        let unknowns = Arc::new(StringVector::from(vec!["unknown"]));
-        let unknowns = Arc::new(ConstantVector::new(unknowns, self.metric_names.len()));
+        let rows_num = self.metric_names.len();
+        let unknowns = Arc::new(ConstantVector::new(
+            Arc::new(StringVector::from(vec!["unknown"])),
+            rows_num,
+        ));
+        let timestamps = Arc::new(ConstantVector::new(
+            Arc::new(TimestampMillisecondVector::from_slice([
+                current_time_millis(),
+            ])),
+            rows_num,
+        ));
 
         let columns: Vec<VectorRef> = vec![
             Arc::new(self.metric_names.finish()),
@@ -179,6 +196,7 @@ impl InformationSchemaMetricsBuilder {
             // TODO(dennis): supports node and node_type for cluster
             unknowns.clone(),
             unknowns,
+            timestamps,
         ];
 
         RecordBatch::new(self.schema.clone(), columns).context(CreateRecordBatchSnafu)
@@ -227,5 +245,6 @@ mod tests {
         assert!(result_literal.contains(METRIC_LABELS));
         assert!(result_literal.contains(NODE));
         assert!(result_literal.contains(NODE_TYPE));
+        assert!(result_literal.contains(TIMESTAMP));
     }
 }
diff --git a/tests/cases/standalone/common/system/information_schema.result b/tests/cases/standalone/common/system/information_schema.result
index fa19e889a25e..8e9486f393df 100644
--- a/tests/cases/standalone/common/system/information_schema.result
+++ b/tests/cases/standalone/common/system/information_schema.result
@@ -611,15 +611,16 @@ select * from CHECK_CONSTRAINTS;
 
 desc table RUNTIME_METRICS;
 
-+-------------+---------+-----+------+---------+---------------+
-| Column      | Type    | Key | Null | Default | Semantic Type |
-+-------------+---------+-----+------+---------+---------------+
-| metric_name | String  |     | NO   |         | FIELD         |
-| value       | Float64 |     | NO   |         | FIELD         |
-| labels      | String  |     | YES  |         | FIELD         |
-| node        | String  |     | NO   |         | FIELD         |
-| node_type   | String  |     | NO   |         | FIELD         |
-+-------------+---------+-----+------+---------+---------------+
++-------------+----------------------+-----+------+---------+---------------+
+| Column      | Type                 | Key | Null | Default | Semantic Type |
++-------------+----------------------+-----+------+---------+---------------+
+| metric_name | String               |     | NO   |         | FIELD         |
+| value       | Float64              |     | NO   |         | FIELD         |
+| labels      | String               |     | YES  |         | FIELD         |
+| node        | String               |     | NO   |         | FIELD         |
+| node_type   | String               |     | NO   |         | FIELD         |
+| timestamp   | TimestampMillisecond |     | NO   |         | FIELD         |
++-------------+----------------------+-----+------+---------+---------------+
 
 use public;