implement EXPLAIN and EXPLAIN PLAN (#2784)

dolthub · Dec 6, 2024 · 151301a · 151301a
1 parent c4c1d5f
commit 151301a
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Showing 8 changed files with 66 additions and 27 deletions.
diff --git a/enginetest/memory_engine_test.go b/enginetest/memory_engine_test.go
@@ -200,9 +200,16 @@ func TestSingleScript(t *testing.T) {
 	t.Skip()
 	var scripts = []queries.ScriptTest{
 		{
-			Name:        "test script",
-			SetUpScript: []string{},
-			Assertions:  []queries.ScriptTestAssertion{},
+			Name: "test script",
+			SetUpScript: []string{
+				"create table t (i int);",
+			},
+			Assertions: []queries.ScriptTestAssertion{
+				{
+					Query:    "select 1 into @a",
+					Expected: []sql.Row{},
+				},
+			},
 		},
 	}
 

diff --git a/go.mod b/go.mod
@@ -6,7 +6,7 @@ require (
 	github.com/dolthub/go-icu-regex v0.0.0-20240916130659-0118adc6b662
 	github.com/dolthub/jsonpath v0.0.2-0.20240227200619-19675ab05c71
 	github.com/dolthub/sqllogictest/go v0.0.0-20201107003712-816f3ae12d81
-	github.com/dolthub/vitess v0.0.0-20241126223332-cd8f828f26ac
+	github.com/dolthub/vitess v0.0.0-20241206185536-814752c66695
 	github.com/go-kit/kit v0.10.0
 	github.com/go-sql-driver/mysql v1.7.2-0.20231213112541-0004702b931d
 	github.com/gocraft/dbr/v2 v2.7.2
@@ -43,4 +43,4 @@ require (
 	gopkg.in/check.v1 v1.0.0-20200902074654-038fdea0a05b // indirect
 )
 
-go 1.22.2
+go 1.23.3
diff --git a/go.sum b/go.sum
@@ -58,20 +58,8 @@ github.com/dolthub/jsonpath v0.0.2-0.20240227200619-19675ab05c71 h1:bMGS25NWAGTE
 github.com/dolthub/jsonpath v0.0.2-0.20240227200619-19675ab05c71/go.mod h1:2/2zjLQ/JOOSbbSboojeg+cAwcRV0fDLzIiWch/lhqI=
 github.com/dolthub/sqllogictest/go v0.0.0-20201107003712-816f3ae12d81 h1:7/v8q9XGFa6q5Ap4Z/OhNkAMBaK5YeuEzwJt+NZdhiE=
 github.com/dolthub/sqllogictest/go v0.0.0-20201107003712-816f3ae12d81/go.mod h1:siLfyv2c92W1eN/R4QqG/+RjjX5W2+gCTRjZxBjI3TY=
-github.com/dolthub/vitess v0.0.0-20241119005402-6a198321d993 h1:MhD6jHjshx2djyUq/uZxtCyHBYAnE3WshhJDUaO9fD8=
-github.com/dolthub/vitess v0.0.0-20241119005402-6a198321d993/go.mod h1:uBvlRluuL+SbEWTCZ68o0xvsdYZER3CEG/35INdzfJM=
-github.com/dolthub/vitess v0.0.0-20241120000209-5ff664bddfc4 h1:C3RSQjvv2T5TdQzRYpLLIbFxfyznzZi25XpOqdu89ng=
-github.com/dolthub/vitess v0.0.0-20241120000209-5ff664bddfc4/go.mod h1:uBvlRluuL+SbEWTCZ68o0xvsdYZER3CEG/35INdzfJM=
-github.com/dolthub/vitess v0.0.0-20241121221517-3e7b5ffc22b0 h1:C8X4RkkWKcrJG6rG+MsdFINX2PhB7ObpbBvFcWsI8K8=
-github.com/dolthub/vitess v0.0.0-20241121221517-3e7b5ffc22b0/go.mod h1:alcJgfdyIhFaAiYyEmuDCFSLCzedz3KCaIclLoCUtJg=
-github.com/dolthub/vitess v0.0.0-20241125233820-b4036b797518 h1:aXx3d3vpAg9/E7oB2AsadnRbBkwQn6Kza7l8JrBjHLE=
-github.com/dolthub/vitess v0.0.0-20241125233820-b4036b797518/go.mod h1:alcJgfdyIhFaAiYyEmuDCFSLCzedz3KCaIclLoCUtJg=
-github.com/dolthub/vitess v0.0.0-20241126003322-7d7ad4a18141 h1:W1jhfE3dnfJGO6spd5BVts4C1iW/g7pb1ml7vm4Swa4=
-github.com/dolthub/vitess v0.0.0-20241126003322-7d7ad4a18141/go.mod h1:alcJgfdyIhFaAiYyEmuDCFSLCzedz3KCaIclLoCUtJg=
-github.com/dolthub/vitess v0.0.0-20241126205153-88972ec5fe52 h1:RH0eygj4DLPQ6fvJCBBk4ZOq3PpeIQU/1ot6Fye9WCU=
-github.com/dolthub/vitess v0.0.0-20241126205153-88972ec5fe52/go.mod h1:alcJgfdyIhFaAiYyEmuDCFSLCzedz3KCaIclLoCUtJg=
-github.com/dolthub/vitess v0.0.0-20241126223332-cd8f828f26ac h1:A0U/OdIqdCkAV0by7MVBbnSyZBsa94ZjIZxx7PhjBW4=
-github.com/dolthub/vitess v0.0.0-20241126223332-cd8f828f26ac/go.mod h1:alcJgfdyIhFaAiYyEmuDCFSLCzedz3KCaIclLoCUtJg=
+github.com/dolthub/vitess v0.0.0-20241206185536-814752c66695 h1:jqTM+/S/LKYdsdretQMalu7dhHupuweSPiPNC2Jpoiw=
+github.com/dolthub/vitess v0.0.0-20241206185536-814752c66695/go.mod h1:1gQZs/byeHLMSul3Lvl3MzioMtOW1je79QYGyi2fd70=
 github.com/dustin/go-humanize v0.0.0-20171111073723-bb3d318650d4/go.mod h1:HtrtbFcZ19U5GC7JDqmcUSB87Iq5E25KnS6fMYU6eOk=
 github.com/eapache/go-resiliency v1.1.0/go.mod h1:kFI+JgMyC7bLPUVY133qvEBtVayf5mFgVsvEsIPBvNs=
 github.com/eapache/go-xerial-snappy v0.0.0-20180814174437-776d5712da21/go.mod h1:+020luEh2TKB4/GOp8oxxtq0Daoen/Cii55CzbTV6DU=

diff --git a/sql/describe.go b/sql/describe.go
@@ -108,6 +108,7 @@ type DescribeOptions struct {
 	Analyze   bool
 	Estimates bool
 	Debug     bool
+	Plan      bool
 }
 
 func (d DescribeOptions) String() string {

diff --git a/sql/plan/describe.go b/sql/plan/describe.go
@@ -16,6 +16,9 @@ package plan
 
 import (
 	"github.com/dolthub/go-mysql-server/sql"
+	"github.com/dolthub/go-mysql-server/sql/types"
+
+	"github.com/dolthub/vitess/go/sqltypes"
 )
 
 // Describe is a node that describes its children.
@@ -102,6 +105,22 @@ func (*DescribeQuery) CollationCoercibility(ctx *sql.Context) (collation sql.Col
 
 // DescribeSchema is the schema returned by a DescribeQuery node.
 var DescribeSchema = sql.Schema{
+	{Name: "id", Type: types.Uint64},
+	{Name: "select_type", Type: types.MustCreateStringWithDefaults(sqltypes.VarChar, 57)},
+	{Name: "table", Type: types.MustCreateStringWithDefaults(sqltypes.VarChar, 192)},
+	{Name: "partitions", Type: types.Text},
+	{Name: "type", Type: types.MustCreateStringWithDefaults(sqltypes.VarChar, 30)},
+	{Name: "possible_keys", Type: types.MustCreateStringWithDefaults(sqltypes.VarChar, 12288)},
+	{Name: "key", Type: types.MustCreateStringWithDefaults(sqltypes.VarChar, 192)},
+	{Name: "key_len", Type: types.MustCreateStringWithDefaults(sqltypes.VarChar, 12288)},
+	{Name: "ref", Type: types.MustCreateStringWithDefaults(sqltypes.VarChar, 3072)},
+	{Name: "rows", Type: types.Uint64},
+	{Name: "filtered", Type: types.Float64},
+	{Name: "Extra", Type: types.MustCreateStringWithDefaults(sqltypes.VarChar, 765)},
+}
+
+// DescribePlanSchema is the schema returned by a DescribeQuery node.
+var DescribePlanSchema = sql.Schema{
 	{Name: "plan", Type: VarChar25000},
 }
 
@@ -112,7 +131,11 @@ func NewDescribeQuery(format sql.DescribeOptions, child sql.Node) *DescribeQuery
 
 // Schema implements the Node interface.
 func (d *DescribeQuery) Schema() sql.Schema {
-	return DescribeSchema
+	if d.Format.Plan {
+		return DescribePlanSchema
+	} else {
+		return DescribeSchema
+	}
 }
 
 func (d *DescribeQuery) Describe(options sql.DescribeOptions) string {

diff --git a/sql/planbuilder/explain.go b/sql/planbuilder/explain.go
@@ -29,6 +29,7 @@ func (b *Builder) buildExplain(inScope *scope, n *sqlparser.Explain) (outScope *
 
 	describeOptions := sql.DescribeOptions{
 		Analyze: n.Analyze,
+		Plan:    n.Plan,
 	}
 
 	formatFlags := strings.Split(n.ExplainFormat, "_")

diff --git a/sql/rowexec/describe_test.go b/sql/rowexec/describe_test.go
@@ -83,6 +83,7 @@ func TestDescribeQuery(t *testing.T) {
 		Analyze:   false,
 		Estimates: false,
 		Debug:     false,
+		Plan:      true,
 	}
 	node := plan.NewDescribeQuery(format, plan.NewProject(
 		[]sql.Expression{

diff --git a/sql/rowexec/show.go b/sql/rowexec/show.go
@@ -74,14 +74,32 @@ func (b *BaseBuilder) buildDescribeQuery(ctx *sql.Context, n *plan.DescribeQuery
 	}
 
 	var rows []sql.Row
-	formatString := sql.Describe(n.Child, n.Format)
-
-	for _, l := range strings.Split(formatString, "\n") {
-		if strings.TrimSpace(l) != "" {
-			rows = append(rows, sql.NewRow(l))
+	if n.Format.Plan {
+		formatString := sql.Describe(n.Child, n.Format)
+		for _, l := range strings.Split(formatString, "\n") {
+			if strings.TrimSpace(l) != "" {
+				rows = append(rows, sql.NewRow(l))
+			}
 		}
-	}
-	return sql.RowsToRowIter(rows...), nil
+		return sql.RowsToRowIter(rows...), nil
+	}
+
+	ctx.Warn(0, "EXPLAIN Output is currently a placeholder; use EXPLAIN PLAN for old behavior")
+	dummyRow := sql.Row{
+		1,        // id
+		"SELECT", // select_type
+		"NULL",   // table
+		"NULL",   // partitions
+		"NULL",   // type
+		"NULL",   // possible_keys
+		"NULL",   // key
+		"NULL",   // key_len
+		"NULL",   // ref
+		"NULL",   // rows
+		"NULL",   // filtered
+		"",       // Extra
+	}
+	return sql.RowsToRowIter(dummyRow), nil
 }
 
 func (b *BaseBuilder) buildShowWarnings(ctx *sql.Context, n plan.ShowWarnings, row sql.Row) (sql.RowIter, error) {