Merge pull request #16860 from knz/20170705-show-improvs

sql: miscellaneous SHOW improvements (part 2)

pkg/sql/crdb_internal.go

@@ -17,17 +17,23 @@
 package sql
 
 import (
+	"bytes"
+	"fmt"
 	"sort"
+	"strings"
 	"time"
 
 	"github.com/pkg/errors"
 	"golang.org/x/net/context"
 
 	"github.com/cockroachdb/cockroach/pkg/build"
 	"github.com/cockroachdb/cockroach/pkg/security"
+	"github.com/cockroachdb/cockroach/pkg/server/serverpb"
+	"github.com/cockroachdb/cockroach/pkg/settings"
 	"github.com/cockroachdb/cockroach/pkg/sql/jobs"
 	"github.com/cockroachdb/cockroach/pkg/sql/parser"
 	"github.com/cockroachdb/cockroach/pkg/sql/sqlbase"
+	"github.com/cockroachdb/cockroach/pkg/util/log"
 )
 
 const crdbInternalName = "crdb_internal"
@@ -42,6 +48,13 @@ var crdbInternal = virtualSchema{
 		crdbInternalStmtStatsTable,
 		crdbInternalJobsTable,
 		crdbInternalSessionTraceTable,
+		crdbInternalClusterSettingsTable,
+		crdbInternalSessionVariablesTable,
+		crdbInternalLocalQueriesTable,
+		crdbInternalClusterQueriesTable,
+		crdbInternalLocalSessionsTable,
+		crdbInternalClusterSessionsTable,
+		crdbInternalBuiltinFunctionsTable,
 	},
 }
 
@@ -490,3 +503,278 @@ CREATE TABLE crdb_internal.session_trace(
 		return nil
 	},
 }
+
+// crdbInternalClusterSettingsTable exposes the list of current
+// cluster settings.
+var crdbInternalClusterSettingsTable = virtualSchemaTable{
+	schema: `
+CREATE TABLE crdb_internal.cluster_settings (
+  name          STRING NOT NULL,
+  current_value STRING NOT NULL,
+  type          STRING NOT NULL,
+  description   STRING NOT NULL
+);
+`,
+	populate: func(ctx context.Context, p *planner, _ string, addRow func(...parser.Datum) error) error {
+		for _, k := range settings.Keys() {
+			setting, _ := settings.Lookup(k)
+			if err := addRow(
+				parser.NewDString(k),
+				parser.NewDString(setting.String()),
+				parser.NewDString(setting.Typ()),
+				parser.NewDString(setting.Description()),
+			); err != nil {
+				return err
+			}
+		}
+		return nil
+	},
+}
+
+// crdbInternalSessionVariablesTable exposes the session variables.
+var crdbInternalSessionVariablesTable = virtualSchemaTable{
+	schema: `
+CREATE TABLE crdb_internal.session_variables (
+  variable STRING NOT NULL,
+  value    STRING NOT NULL
+);
+`,
+	populate: func(ctx context.Context, p *planner, _ string, addRow func(...parser.Datum) error) error {
+		for _, vName := range varNames {
+			gen := varGen[vName]
+			value := gen.Get(p.session)
+			if err := addRow(
+				parser.NewDString(vName),
+				parser.NewDString(value),
+			); err != nil {
+				return err
+			}
+		}
+		return nil
+	},
+}
+
+const queriesSchemaPattern = `
+CREATE TABLE crdb_internal.%s (
+  node_id          INT NOT NULL,   -- the node on which the query is running
+  username         STRING,         -- the user running the query
+  start            TIMESTAMP,      -- the start time of the query
+  query            STRING,         -- the SQL code of the query
+  client_address   STRING,         -- the address of the client that issued the query
+  application_name STRING,         -- the name of the application as per SET application_name
+  distributed      BOOL,           -- whether the query is running distributed
+  phase            STRING          -- the current execution phase
+);
+`
+
+// crdbInternalLocalQueriesTable exposes the list of running queries
+// on the current node. The results are dependent on the current user.
+var crdbInternalLocalQueriesTable = virtualSchemaTable{
+	schema: fmt.Sprintf(queriesSchemaPattern, "node_queries"),
+	populate: func(ctx context.Context, p *planner, _ string, addRow func(...parser.Datum) error) error {
+		req := serverpb.ListSessionsRequest{Username: p.session.User}
+		response, err := p.session.execCfg.StatusServer.ListLocalSessions(ctx, &req)
+		if err != nil {
+			return err
+		}
+		return populateQueriesTable(ctx, addRow, response)
+	},
+}
+
+// crdbInternalClusterQueriesTable exposes the list of running queries
+// on the entire cluster. The result is dependent on the current user.
+var crdbInternalClusterQueriesTable = virtualSchemaTable{
+	schema: fmt.Sprintf(queriesSchemaPattern, "cluster_queries"),
+	populate: func(ctx context.Context, p *planner, _ string, addRow func(...parser.Datum) error) error {
+		req := serverpb.ListSessionsRequest{Username: p.session.User}
+		response, err := p.session.execCfg.StatusServer.ListSessions(ctx, &req)
+		if err != nil {
+			return err
+		}
+		return populateQueriesTable(ctx, addRow, response)
+	},
+}
+
+func populateQueriesTable(
+	ctx context.Context, addRow func(...parser.Datum) error, response *serverpb.ListSessionsResponse,
+) error {
+	for _, session := range response.Sessions {
+		for _, query := range session.ActiveQueries {
+			isDistributedDatum := parser.DNull
+			phase := strings.ToLower(query.Phase.String())
+			if phase == "executing" {
+				isDistributedDatum = parser.DBoolFalse
+				if query.IsDistributed {
+					isDistributedDatum = parser.DBoolTrue
+				}
+			}
+			if err := addRow(
+				parser.NewDInt(parser.DInt(session.NodeID)),
+				parser.NewDString(session.Username),
+				parser.MakeDTimestamp(query.Start, time.Microsecond),
+				parser.NewDString(query.Sql),
+				parser.NewDString(session.ClientAddress),
+				parser.NewDString(session.ApplicationName),
+				isDistributedDatum,
+				parser.NewDString(phase),
+			); err != nil {
+				return err
+			}
+		}
+	}
+
+	for _, rpcErr := range response.Errors {
+		log.Warning(ctx, rpcErr.Message)
+		if rpcErr.NodeID != 0 {
+			// Add a row with this node ID, and nulls for all other columns
+			if err := addRow(
+				parser.NewDInt(parser.DInt(rpcErr.NodeID)),
+				parser.DNull,
+				parser.DNull,
+				parser.DNull,
+				parser.DNull,
+				parser.DNull,
+				parser.DNull,
+				parser.DNull,
+			); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+const sessionsSchemaPattern = `
+CREATE TABLE crdb_internal.%s (
+  node_id            INT NOT NULL,   -- the node on which the query is running
+  username           STRING,         -- the user running the query
+  client_address     STRING,         -- the address of the client that issued the query
+  application_name   STRING,         -- the name of the application as per SET application_name
+  active_queries     STRING,         -- the currently running queries as SQL
+  session_start      TIMESTAMP,      -- the time when the session was opened
+  oldest_query_start TIMESTAMP,      -- the time when the oldest query in the session was started
+  kv_txn             STRING          -- the ID of the current KV transaction
+);
+`
+
+// crdbInternalLocalSessionsTable exposes the list of running sessions
+// on the current node. The results are dependent on the current user.
+var crdbInternalLocalSessionsTable = virtualSchemaTable{
+	schema: fmt.Sprintf(sessionsSchemaPattern, "node_sessions"),
+	populate: func(ctx context.Context, p *planner, _ string, addRow func(...parser.Datum) error) error {
+		req := serverpb.ListSessionsRequest{Username: p.session.User}
+		response, err := p.session.execCfg.StatusServer.ListLocalSessions(ctx, &req)
+		if err != nil {
+			return err
+		}
+		return populateSessionsTable(ctx, addRow, response)
+	},
+}
+
+// crdbInternalClusterSessionsTable exposes the list of running sessions
+// on the entire cluster. The result is dependent on the current user.
+var crdbInternalClusterSessionsTable = virtualSchemaTable{
+	schema: fmt.Sprintf(sessionsSchemaPattern, "cluster_sessions"),
+	populate: func(ctx context.Context, p *planner, _ string, addRow func(...parser.Datum) error) error {
+		req := serverpb.ListSessionsRequest{Username: p.session.User}
+		response, err := p.session.execCfg.StatusServer.ListSessions(ctx, &req)
+		if err != nil {
+			return err
+		}
+		return populateSessionsTable(ctx, addRow, response)
+	},
+}
+
+func populateSessionsTable(
+	ctx context.Context, addRow func(...parser.Datum) error, response *serverpb.ListSessionsResponse,
+) error {
+	for _, session := range response.Sessions {
+		// Generate active_queries and oldest_query_start
+		var activeQueries bytes.Buffer
+		var oldestStart time.Time
+		var oldestStartDatum parser.Datum
+
+		for _, query := range session.ActiveQueries {
+			activeQueries.WriteString(query.Sql)
+			activeQueries.WriteString("; ")
+
+			if oldestStart.IsZero() || query.Start.Before(oldestStart) {
+				oldestStart = query.Start
+			}
+		}
+
+		if oldestStart.IsZero() {
+			oldestStartDatum = parser.DNull
+		} else {
+			oldestStartDatum = parser.MakeDTimestamp(oldestStart, time.Microsecond)
+		}
+
+		kvTxnIDDatum := parser.DNull
+		if session.KvTxnID != nil {
+			kvTxnIDDatum = parser.NewDString(session.KvTxnID.String())
+		}
+
+		if err := addRow(
+			parser.NewDInt(parser.DInt(session.NodeID)),
+			parser.NewDString(session.Username),
+			parser.NewDString(session.ClientAddress),
+			parser.NewDString(session.ApplicationName),
+			parser.NewDString(activeQueries.String()),
+			parser.MakeDTimestamp(session.Start, time.Microsecond),
+			oldestStartDatum,
+			kvTxnIDDatum,
+		); err != nil {
+			return err
+		}
+	}
+
+	for _, rpcErr := range response.Errors {
+		log.Warning(ctx, rpcErr.Message)
+		if rpcErr.NodeID != 0 {
+			// Add a row with this node ID, and nulls for all other columns
+			if err := addRow(
+				parser.NewDInt(parser.DInt(rpcErr.NodeID)),
+				parser.DNull,
+				parser.DNull,
+				parser.DNull,
+				parser.DNull,
+				parser.DNull,
+				parser.DNull,
+				parser.DNull,
+			); err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
+// crdbInternalBuiltinFunctionsTable exposes the built-in function
+// metadata.
+var crdbInternalBuiltinFunctionsTable = virtualSchemaTable{
+	schema: `
+CREATE TABLE crdb_internal.builtin_functions (
+  function  STRING NOT NULL,
+  signature STRING NOT NULL,
+  category  STRING NOT NULL,
+  details   STRING NOT NULL
+);
+`,
+	populate: func(ctx context.Context, _ *planner, _ string, addRow func(...parser.Datum) error) error {
+		for _, name := range parser.AllBuiltinNames {
+			overloads := parser.Builtins[name]
+			for _, f := range overloads {
+				if err := addRow(
+					parser.NewDString(name),
+					parser.NewDString(f.Signature()),
+					parser.NewDString(f.Category()),
+					parser.NewDString(f.Info),
+				); err != nil {
+					return err
+				}
+			}
+		}
+		return nil
+	},
+}

pkg/sql/logictest/testdata/logic_test/explain

@@ -136,37 +136,47 @@ EXPLAIN SHOW TABLES
 1  render
 2  filter
 3  values
-3          size   5 columns, 52 rows
+3          size   5 columns, 59 rows
 
 query ITTT
 EXPLAIN SHOW DATABASE
 ----
-0  values
-0          size  1 column, 1 row
+0  render
+1  filter
+2  values
+2          size  2 columns, 19 rows
 
 query ITTT
 EXPLAIN SHOW TIME ZONE
 ----
-0  values
-0          size  1 column, 1 row
+0  render
+1  filter
+2  values
+2          size  2 columns, 19 rows
 
 query ITTT
 EXPLAIN SHOW DEFAULT_TRANSACTION_ISOLATION
 ----
-0  values
-0          size  1 column, 1 row
+0  render
+1  filter
+2  values
+2          size  2 columns, 19 rows
 
 query ITTT
 EXPLAIN SHOW TRANSACTION ISOLATION LEVEL
 ----
-0  values
-0          size  1 column, 1 row
+0  render
+1  filter
+2  values
+2          size  2 columns, 19 rows
 
 query ITTT
 EXPLAIN SHOW TRANSACTION PRIORITY
 ----
-0  values
-0          size  1 column, 1 row
+0  render
+1  filter
+2  values
+2          size  2 columns, 19 rows
 
 query ITTT
 EXPLAIN SHOW COLUMNS FROM foo
@@ -182,7 +192,7 @@ EXPLAIN SHOW COLUMNS FROM foo
 5  render
 6  filter
 7  values
-7          size      13 columns, 459 rows
+7          size      13 columns, 501 rows
 5  render
 6  filter
 7  values