sql: add backward compatibility to stats and plan

pkg/sql/sqlstats/persistedsqlstats/sqlstatsutil/json_decoding.go

@@ -55,16 +55,18 @@ func DecodeStmtStatsStatisticsJSON(jsonVal json.JSON, result *roachpb.StatementS
 func JSONToExplainTreePlanNode(jsonVal json.JSON) (*roachpb.ExplainTreePlanNode, error) {
  node := roachpb.ExplainTreePlanNode{}
 
- nameAttr, err := safeFetchVal(jsonVal, "Name")
+ nameAttr, err := jsonVal.FetchValKey("Name")
  if err != nil {
  return nil, err
  }
 
- str, err := nameAttr.AsText()
- if err != nil {
- return nil, err
+ if nameAttr != nil {
+ str, err := nameAttr.AsText()
+ if err != nil {
+ return nil, err
+ }
+ node.Name = *str
  }
- node.Name = *str
 
  iter, err := jsonVal.ObjectIter()
  if err != nil {
@@ -86,15 +88,17 @@ func JSONToExplainTreePlanNode(jsonVal json.JSON) (*roachpb.ExplainTreePlanNode,
 
  if key == "Children" {
  for childIdx := 0; childIdx < value.Len(); childIdx++ {
- childJSON, err := safeFetchValIdx(value, childIdx)
+ childJSON, err := value.FetchValIdx(childIdx)
  if err != nil {
  return nil, err
  }
- child, err := JSONToExplainTreePlanNode(childJSON)
- if err != nil {
- return nil, err
+ if childJSON != nil {
+ child, err := JSONToExplainTreePlanNode(childJSON)
+ if err != nil {
+ return nil, err
+ }
+ node.Children = append(node.Children, child)
  }
- node.Children = append(node.Children, child)
  }
  } else {
  str, err := value.AsText()

pkg/sql/sqlstats/persistedsqlstats/sqlstatsutil/json_encoding_test.go

@@ -146,6 +146,121 @@ func TestSQLStatsJsonEncoding(t *testing.T) {
  require.Equal(t, input, actualJSONUnmarshalled)
  })
 
+ // When a new statistic is added to a statement payload, older versions won't have the
+ // new parameter, so this test is to confirm that all other parameters will be set and
+ // the new one will be empty, without breaking the decoding process.
+ t.Run("statement_statistics with new parameter", func(t *testing.T) {
+ data := genRandomData()
+ expectedStatistics := roachpb.CollectedStatementStatistics{}
+
+ expectedMetadataStrTemplate := `
+ {
+ "stmtTyp": "{{.String}}",
+ "query": "{{.String}}",
+ "db": "{{.String}}",
+ "distsql": {{.Bool}},
+ "failed": {{.Bool}},
+ "implicitTxn": {{.Bool}},
+ "vec": {{.Bool}},
+ "fullScan": {{.Bool}}
+ }
+ `
+ expectedStatisticsStrTemplate := `
+ {
+ "statistics": {
+ "cnt": {{.Int64}},
+ "firstAttemptCnt": {{.Int64}},
+ "maxRetries": {{.Int64}},
+ "lastExecAt": "{{stringifyTime .Time}}",
+ "numRows": {
+ "mean": {{.Float}},
+ "sqDiff": {{.Float}}
+ },
+ "parseLat": {
+ "mean": {{.Float}},
+ "sqDiff": {{.Float}}
+ },
+ "planLat": {
+ "mean": {{.Float}},
+ "sqDiff": {{.Float}}
+ },
+ "runLat": {
+ "mean": {{.Float}},
+ "sqDiff": {{.Float}}
+ },
+ "svcLat": {
+ "mean": {{.Float}},
+ "sqDiff": {{.Float}}
+ },
+ "ovhLat": {
+ "mean": {{.Float}},
+ "sqDiff": {{.Float}}
+ },
+ "bytesRead": {
+ "mean": {{.Float}},
+ "sqDiff": {{.Float}}
+ },
+ "rowsRead": {
+ "mean": {{.Float}},
+ "sqDiff": {{.Float}}
+ },
+ "rowsWritten": {
+ "mean": {{.Float}},
+ "sqDiff": {{.Float}}
+ },
+ "nodes": [{{joinInts .IntArray}}]
+ },
+ "execution_statistics": {
+ "cnt": {{.Int64}},
+ "networkBytes": {
+ "mean": {{.Float}},
+ "sqDiff": {{.Float}}
+ },
+ "maxMemUsage": {
+ "mean": {{.Float}},
+ "sqDiff": {{.Float}}
+ },
+ "contentionTime": {
+ "mean": {{.Float}},
+ "sqDiff": {{.Float}}
+ },
+ "networkMsgs": {
+ "mean": {{.Float}},
+ "sqDiff": {{.Float}}
+ },
+ "maxDiskUsage": {
+ "mean": {{.Float}},
+ "sqDiff": {{.Float}}
+ }
+ }
+ }
+ `
+
+ fillTemplate(t, expectedMetadataStrTemplate, data)
+ fillTemplate(t, expectedStatisticsStrTemplate, data)
+ fillObject(t, reflect.ValueOf(&expectedStatistics), &data)
+
+ actualMetadataJSON, err := BuildStmtMetadataJSON(&expectedStatistics)
+ require.NoError(t, err)
+ actualStatisticsJSON, err := BuildStmtStatisticsJSON(&expectedStatistics.Stats)
+ require.NoError(t, err)
+
+ var actualJSONUnmarshalled roachpb.CollectedStatementStatistics
+
+ err = DecodeStmtStatsMetadataJSON(actualMetadataJSON, &actualJSONUnmarshalled)
+ require.NoError(t, err)
+
+ // Remove one of the statistics on the object so its value doesn't get populated on
+ // the final actualJSONUnmarshalled.Stats.
+ actualStatisticsJSON, _, _ = actualStatisticsJSON.RemovePath([]string{"statistics", "numRows"})
+ // Initialize the field again to remove the existing value.
+ expectedStatistics.Stats.NumRows = roachpb.NumericStat{}
+
+ err = DecodeStmtStatsStatisticsJSON(actualStatisticsJSON, &actualJSONUnmarshalled.Stats)
+ require.NoError(t, err)
+ require.Equal(t, expectedStatistics, actualJSONUnmarshalled)
+ })
+
  t.Run("transaction_statistics", func(t *testing.T) {
  data := genRandomData()
 

pkg/sql/sqlstats/persistedsqlstats/sqlstatsutil/json_impl.go

@@ -296,13 +296,15 @@ func (jf jsonFields) decodeJSON(js json.JSON) (err error) {
 
  for i := range jf {
  fieldName = jf[i].field
- field, err := safeFetchVal(js, fieldName)
+ field, err := js.FetchValKey(fieldName)
  if err != nil {
  return err
  }
- err = jf[i].val.decodeJSON(field)
- if err != nil {
- return err
+ if field != nil {
+ err = jf[i].val.decodeJSON(field)
+ if err != nil {
+ return err
+ }
  }
  }
 
@@ -437,25 +439,3 @@ func (d *decimal) decodeJSON(js json.JSON) error {
 func (d *decimal) encodeJSON() (json.JSON, error) {
  return json.FromDecimal(*(*apd.Decimal)(d)), nil
 }
-
-func safeFetchVal(jsonVal json.JSON, key string) (json.JSON, error) {
- field, err := jsonVal.FetchValKey(key)
- if err != nil {
- return nil, err
- }
- if field == nil {
- return nil, errors.Newf("%s field is not found in the JSON payload", key)
- }
- return field, nil
-}
-
-func safeFetchValIdx(jsonVal json.JSON, idx int) (json.JSON, error) {
- field, err := jsonVal.FetchValIdx(idx)
- if err != nil {
- return nil, err
- }
- if field == nil {
- return nil, errors.Newf("%dth element is not found in the JSON payload", idx)
- }
- return field, nil
-}