feat: format_version

Author: radim

internal/schema/introspect.go

@@ -144,17 +144,18 @@ func IntrospectSchema(ctx context.Context, pool Querier) (*SchemaSnapshot, error
 	)
 
 	snap := &SchemaSnapshot{
-		PgVersion:  pgVersion,
-		Database:   database,
-		Timestamp:  time.Now().UTC(),
-		Tables:     tables,
-		Enums:      enums,
-		Domains:    domains,
-		Composites: composites,
-		Views:      views,
-		Functions:  functions,
-		Extensions: extensions,
-		GUCs:       gucs,
+		FormatVersion: FormatVersion,
+		PgVersion:     pgVersion,
+		Database:      database,
+		Timestamp:     time.Now().UTC(),
+		Tables:        tables,
+		Enums:         enums,
+		Domains:       domains,
+		Composites:    composites,
+		Views:         views,
+		Functions:     functions,
+		Extensions:    extensions,
+		GUCs:          gucs,
 	}
 	snap.ContentHash = ComputeContentHash(snap)
 	return snap, nil
@@ -249,7 +250,6 @@ type (
 		name       string
 		definition string
 	}
-
 )
 
 // Fetchers - each uses a named query from sql/introspect.sql
@@ -495,7 +495,6 @@ func fetchTriggers(ctx context.Context, pool Querier) ([]rawTrigger, error) {
 	})
 }
 
-
 func fetchViews(ctx context.Context, pool Querier) ([]View, error) {
 	rows, err := query(ctx, pool, "fetch-views")
 	if err != nil {

internal/schema/snapshot.go

@@ -46,6 +46,8 @@ type (
 
 // Enum values.
 const (
+	FormatVersion = snapshot.FormatVersion
+
 	ConstraintPrimaryKey = snapshot.ConstraintPrimaryKey
 	ConstraintForeignKey = snapshot.ConstraintForeignKey
 	ConstraintUnique     = snapshot.ConstraintUnique

internal/schema/stats.go

@@ -41,6 +41,7 @@ func CapturePlannerStats(ctx context.Context, pool Querier, schemaRefHash string
 	}
 
 	snap := &PlannerStatsSnapshot{
+		FormatVersion: FormatVersion,
 		SchemaRefHash: schemaRefHash,
 		Database:      database,
 		Timestamp:     time.Now().UTC(),
@@ -70,6 +71,7 @@ func CaptureActivityStats(ctx context.Context, pool Querier, schemaRefHash, sour
 	}
 
 	snap := &ActivityStatsSnapshot{
+		FormatVersion: FormatVersion,
 		SchemaRefHash: schemaRefHash,
 		Node:          *node,
 		Tables:        tables,

pkg/snapshot/types.go

@@ -7,21 +7,25 @@ import (
 	"time"
 )
 
+// 0 means legacy. not hashed.
+const FormatVersion = 1
+
 // DDL-only schema snapshot; sizing/activity live in AnnotatedSchema
 type SchemaSnapshot struct {
-	PgVersion   string          `json:"pg_version"`
-	Database    string          `json:"database"`
-	Timestamp   time.Time       `json:"timestamp"`
-	ContentHash string          `json:"content_hash"`
-	Source      *string         `json:"source,omitempty"`
-	Tables      []Table         `json:"tables"`
-	Enums       []EnumType      `json:"enums"`
-	Domains     []DomainType    `json:"domains"`
-	Composites  []CompositeType `json:"composites"`
-	Views       []View          `json:"views"`
-	Functions   []Function      `json:"functions"`
-	Extensions  []Extension     `json:"extensions"`
-	GUCs        []GucSetting    `json:"gucs"`
+	FormatVersion int             `json:"format_version"`
+	PgVersion     string          `json:"pg_version"`
+	Database      string          `json:"database"`
+	Timestamp     time.Time       `json:"timestamp"`
+	ContentHash   string          `json:"content_hash"`
+	Source        *string         `json:"source,omitempty"`
+	Tables        []Table         `json:"tables"`
+	Enums         []EnumType      `json:"enums"`
+	Domains       []DomainType    `json:"domains"`
+	Composites    []CompositeType `json:"composites"`
+	Views         []View          `json:"views"`
+	Functions     []Function      `json:"functions"`
+	Extensions    []Extension     `json:"extensions"`
+	GUCs          []GucSetting    `json:"gucs"`
 }
 
 type Table struct {
@@ -441,6 +445,7 @@ type IndexActivityEntry struct {
 
 // Persisted planner inputs; schema_ref_hash binds rows to a SchemaSnapshot
 type PlannerStatsSnapshot struct {
+	FormatVersion int       `json:"format_version"`
 	SchemaRefHash string    `json:"schema_ref_hash"`
 	ContentHash   string    `json:"content_hash"`
 	Database      string    `json:"database"`
@@ -456,6 +461,7 @@ type PlannerStatsSnapshot struct {
 
 // Persisted per-node activity counters
 type ActivityStatsSnapshot struct {
+	FormatVersion int                  `json:"format_version"`
 	SchemaRefHash string               `json:"schema_ref_hash"`
 	ContentHash   string               `json:"content_hash"`
 	Node          NodeIdentity         `json:"node"`