Convert CREATE INDEX SQL into pgroll operation (#551)

Convert the majority of `CREATE INDEX` statements into `OpCreateIndex`

The following cases are covered:

```sql
CREATE INDEX idx_name ON foo (bar)
CREATE INDEX idx_name ON foo (bar ASC)
CREATE INDEX idx_name ON foo USING btree (bar)
CREATE INDEX idx_name ON foo USING brin (bar)
CREATE INDEX idx_name ON foo USING gin (bar)
CREATE INDEX idx_name ON foo USING gist (bar)
CREATE INDEX idx_name ON foo USING hash (bar)
CREATE INDEX idx_name ON foo USING spgist (bar)
CREATE INDEX CONCURRENTLY idx_name ON foo (bar)
CREATE INDEX idx_name ON schema.foo (bar)
CREATE INDEX idx_name ON foo (bar, baz)
CREATE UNIQUE INDEX idx_name ON foo (bar)
CREATE INDEX idx_name ON foo (bar) WHERE (foo > 0)
CREATE INDEX idx_name ON foo (bar) WHERE foo > 0
CREATE INDEX idx_name ON foo (bar) WITH (fillfactor = 70)
CREATE INDEX idx_name ON foo (bar) WITH (deduplicate_items = true)
CREATE INDEX idx_name ON foo (bar) WITH (buffering = ON)
CREATE INDEX idx_name ON foo (bar) WITH (buffering = OFF)
CREATE INDEX idx_name ON foo (bar) WITH (buffering = AUTO)
CREATE INDEX idx_name ON foo (bar) WITH (fastupdate = true)
CREATE INDEX idx_name ON foo (bar) WITH (pages_per_range = 100)
CREATE INDEX idx_name ON foo (bar) WITH (autosummarize = true)
CREATE INDEX idx_name ON foo (bar) WITH (fillfactor = 70, deduplicate_items = true)
```

And the following unsupported cases fall back to RAW SQL:

```sql
CREATE INDEX idx_name ON foo (bar) TABLESPACE baz
CREATE INDEX idx_name ON foo (bar COLLATE en_US)
CREATE INDEX idx_name ON foo (bar DESC)
CREATE INDEX idx_name ON foo (bar NULLS FIRST)
CREATE INDEX idx_name ON foo (bar NULLS LAST)
CREATE INDEX idx_name ON foo (bar) INCLUDE (baz)
CREATE INDEX idx_name ON foo (bar opclass (test = test))
CREATE INDEX idx_name ON foo (bar opclass)
CREATE INDEX idx_name ON ONLY foo (bar)
CREATE INDEX idx_name ON foo(a) NULLS NOT DISTINCT
CREATE INDEX IF NOT EXISTS idx_name ON foo(a)
CREATE INDEX idx_name ON foo(LOWER(a))
CREATE INDEX idx_name ON foo(a, LOWER(b))
```

pkg/migrations/op_create_index.go

@@ -97,3 +97,23 @@ func quoteColumnNames(columns []string) (quoted []string) {
 	}
 	return quoted
 }
+
+// ParseCreateIndexMethod parsed index methods into OpCreateIndexMethod
+func ParseCreateIndexMethod(method string) (OpCreateIndexMethod, error) {
+	switch method {
+	case "btree":
+		return OpCreateIndexMethodBtree, nil
+	case "hash":
+		return OpCreateIndexMethodHash, nil
+	case "gist":
+		return OpCreateIndexMethodGist, nil
+	case "spgist":
+		return OpCreateIndexMethodSpgist, nil
+	case "gin":
+		return OpCreateIndexMethodGin, nil
+	case "brin":
+		return OpCreateIndexMethodBrin, nil
+	default:
+		return OpCreateIndexMethodBtree, fmt.Errorf("unknown method: %s", method)
+	}
+}

pkg/sql2pgroll/convert.go

@@ -47,6 +47,8 @@ func convert(sql string) (migrations.Operations, error) {
 		return convertRenameStmt(node.RenameStmt)
 	case *pgq.Node_DropStmt:
 		return convertDropStatement(node.DropStmt)
+	case *pgq.Node_IndexStmt:
+		return convertCreateIndexStmt(node.IndexStmt)
 	default:
 		return makeRawSQLOperation(sql), nil
 	}

pkg/sql2pgroll/create_index.go

@@ -0,0 +1,124 @@
+// SPDX-License-Identifier: Apache-2.0
+
+package sql2pgroll
+
+import (
+	"fmt"
+
+	pgq "github.com/xataio/pg_query_go/v6"
+
+	"github.com/xataio/pgroll/pkg/migrations"
+)
+
+// convertCreateIndexStmt converts CREATE INDEX statements into pgroll operations.
+func convertCreateIndexStmt(stmt *pgq.IndexStmt) (migrations.Operations, error) {
+	if !canConvertCreateIndexStmt(stmt) {
+		return nil, nil
+	}
+
+	// Get the qualified table name
+	tableName := getQualifiedRelationName(stmt.GetRelation())
+	var columns []string
+
+	// Get the columns on which the index is defined
+	for _, param := range stmt.GetIndexParams() {
+		if colName := param.GetIndexElem().GetName(); colName != "" {
+			columns = append(columns, colName)
+		}
+	}
+
+	// Parse the access method
+	method, err := migrations.ParseCreateIndexMethod(stmt.GetAccessMethod())
+	if err != nil {
+		return nil, fmt.Errorf("parse create index method: %w", err)
+	}
+
+	// Get index uniqueness
+	unique := false
+	if stmt.GetUnique() {
+		unique = true
+	}
+
+	// Deparse WHERE clause
+	var predicate string
+	if where := stmt.GetWhereClause(); where != nil {
+		predicate, err = pgq.DeparseExpr(where)
+		if err != nil {
+			return nil, fmt.Errorf("parsing where clause: %w", err)
+		}
+	}
+
+	// Deparse storage parameters
+	var storageParams string
+	if len(stmt.GetOptions()) > 0 {
+		storageParams, err = pgq.DeparseRelOptions(stmt.GetOptions())
+		if err != nil {
+			return nil, fmt.Errorf("parsing options: %w", err)
+		}
+		// strip outer parentheses
+		storageParams = storageParams[1 : len(storageParams)-1]
+	}
+
+	return migrations.Operations{
+		&migrations.OpCreateIndex{
+			Table:             tableName,
+			Columns:           columns,
+			Name:              stmt.GetIdxname(),
+			Method:            method,
+			Unique:            unique,
+			Predicate:         predicate,
+			StorageParameters: storageParams,
+		},
+	}, nil
+}
+
+func canConvertCreateIndexStmt(stmt *pgq.IndexStmt) bool {
+	// Tablespaces are not supported
+	if stmt.GetTableSpace() != "" {
+		return false
+	}
+	// Indexes with INCLUDE are not supported
+	if stmt.GetIndexIncludingParams() != nil {
+		return false
+	}
+	// Indexes created with ONLY are not supported
+	if !stmt.GetRelation().GetInh() {
+		return false
+	}
+	// Indexes with NULLS NOT DISTINCT are not supported
+	if stmt.GetNullsNotDistinct() {
+		return false
+	}
+	// IF NOT EXISTS is unsupported
+	if stmt.GetIfNotExists() {
+		return false
+	}
+	// Indexes defined on expressions are not supported
+	for _, node := range stmt.GetIndexParams() {
+		if node.GetIndexElem().GetExpr() != nil {
+			return false
+		}
+	}
+
+	for _, param := range stmt.GetIndexParams() {
+		// Indexes with non-default collations are not supported
+		if param.GetIndexElem().GetCollation() != nil {
+			return false
+		}
+		// Indexes with non-default ordering are not supported
+		ordering := param.GetIndexElem().GetOrdering()
+		if ordering != pgq.SortByDir_SORTBY_DEFAULT && ordering != pgq.SortByDir_SORTBY_ASC {
+			return false
+		}
+		// Indexes with non-default nulls ordering are not supported
+		if param.GetIndexElem().GetNullsOrdering() != pgq.SortByNulls_SORTBY_NULLS_DEFAULT {
+			return false
+		}
+		// Indexes with opclasses are not supported
+		if param.GetIndexElem().GetOpclass() != nil || param.GetIndexElem().GetOpclassopts() != nil {
+			return false
+		}
+	}
+
+	return true
+}

pkg/sql2pgroll/create_index_test.go

@@ -0,0 +1,168 @@
+// SPDX-License-Identifier: Apache-2.0
+
+package sql2pgroll_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/xataio/pgroll/pkg/migrations"
+	"github.com/xataio/pgroll/pkg/sql2pgroll"
+	"github.com/xataio/pgroll/pkg/sql2pgroll/expect"
+)
+
+func TestConvertCreateIndexStatements(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		sql        string
+		expectedOp migrations.Operation
+	}{
+		{
+			sql:        "CREATE INDEX idx_name ON foo (bar)",
+			expectedOp: expect.CreateIndexOp1,
+		},
+		{
+			sql:        "CREATE INDEX idx_name ON foo (bar ASC)",
+			expectedOp: expect.CreateIndexOp1,
+		},
+		{
+			sql:        "CREATE INDEX idx_name ON foo USING btree (bar)",
+			expectedOp: expect.CreateIndexOp1,
+		},
+		{
+			sql:        "CREATE INDEX idx_name ON foo USING brin (bar)",
+			expectedOp: expect.CreateIndexOp1WithMethod("brin"),
+		},
+		{
+			sql:        "CREATE INDEX idx_name ON foo USING gin (bar)",
+			expectedOp: expect.CreateIndexOp1WithMethod("gin"),
+		},
+		{
+			sql:        "CREATE INDEX idx_name ON foo USING gist (bar)",
+			expectedOp: expect.CreateIndexOp1WithMethod("gist"),
+		},
+		{
+			sql:        "CREATE INDEX idx_name ON foo USING hash (bar)",
+			expectedOp: expect.CreateIndexOp1WithMethod("hash"),
+		},
+		{
+			sql:        "CREATE INDEX idx_name ON foo USING spgist (bar)",
+			expectedOp: expect.CreateIndexOp1WithMethod("spgist"),
+		},
+		{
+			sql:        "CREATE INDEX CONCURRENTLY idx_name ON foo (bar)",
+			expectedOp: expect.CreateIndexOp1,
+		},
+		{
+			sql:        "CREATE INDEX idx_name ON schema.foo (bar)",
+			expectedOp: expect.CreateIndexOp2,
+		},
+		{
+			sql:        "CREATE INDEX idx_name ON foo (bar, baz)",
+			expectedOp: expect.CreateIndexOp3,
+		},
+		{
+			sql:        "CREATE UNIQUE INDEX idx_name ON foo (bar)",
+			expectedOp: expect.CreateIndexOp4,
+		},
+		{
+			sql:        "CREATE INDEX idx_name ON foo (bar) WHERE (foo > 0)",
+			expectedOp: expect.CreateIndexOp5,
+		},
+		{
+			sql:        "CREATE INDEX idx_name ON foo (bar) WHERE foo > 0",
+			expectedOp: expect.CreateIndexOp5,
+		},
+		{
+			sql:        "CREATE INDEX idx_name ON foo (bar) WITH (fillfactor = 70)",
+			expectedOp: expect.CreateIndexOpWithStorageParam("fillfactor=70"),
+		},
+		{
+			sql:        "CREATE INDEX idx_name ON foo (bar) WITH (deduplicate_items = true)",
+			expectedOp: expect.CreateIndexOpWithStorageParam("deduplicate_items=true"),
+		},
+		{
+			sql:        "CREATE INDEX idx_name ON foo (bar) WITH (buffering = ON)",
+			expectedOp: expect.CreateIndexOpWithStorageParam("buffering=on"),
+		},
+		{
+			sql:        "CREATE INDEX idx_name ON foo (bar) WITH (buffering = OFF)",
+			expectedOp: expect.CreateIndexOpWithStorageParam("buffering=off"),
+		},
+		{
+			sql:        "CREATE INDEX idx_name ON foo (bar) WITH (buffering = AUTO)",
+			expectedOp: expect.CreateIndexOpWithStorageParam("buffering=auto"),
+		},
+		{
+			sql:        "CREATE INDEX idx_name ON foo (bar) WITH (fastupdate = true)",
+			expectedOp: expect.CreateIndexOpWithStorageParam("fastupdate=true"),
+		},
+		{
+			sql:        "CREATE INDEX idx_name ON foo (bar) WITH (pages_per_range = 100)",
+			expectedOp: expect.CreateIndexOpWithStorageParam("pages_per_range=100"),
+		},
+		{
+			sql:        "CREATE INDEX idx_name ON foo (bar) WITH (autosummarize = true)",
+			expectedOp: expect.CreateIndexOpWithStorageParam("autosummarize=true"),
+		},
+		{
+			sql:        "CREATE INDEX idx_name ON foo (bar) WITH (fillfactor = 70, deduplicate_items = true)",
+			expectedOp: expect.CreateIndexOpWithStorageParam("fillfactor=70, deduplicate_items=true"),
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.sql, func(t *testing.T) {
+			ops, err := sql2pgroll.Convert(tc.sql)
+			require.NoError(t, err)
+
+			require.Len(t, ops, 1)
+
+			assert.Equal(t, tc.expectedOp, ops[0])
+		})
+	}
+}
+
+func TestUnconvertableCreateIndexStatements(t *testing.T) {
+	t.Parallel()
+
+	tests := []string{
+		// Tablespaces are not supported
+		"CREATE INDEX idx_name ON foo (bar) TABLESPACE baz",
+		// Index collations are not supported
+		"CREATE INDEX idx_name ON foo (bar COLLATE en_US)",
+		// Index ordering other than the default ASC is not supported
+		"CREATE INDEX idx_name ON foo (bar DESC)",
+		// Index nulls ordering is not supported
+		"CREATE INDEX idx_name ON foo (bar NULLS FIRST)",
+		"CREATE INDEX idx_name ON foo (bar NULLS LAST)",
+		// Included columns are not supported
+		"CREATE INDEX idx_name ON foo (bar) INCLUDE (baz)",
+		// opclasses with or without options are not supported
+		"CREATE INDEX idx_name ON foo (bar opclass (test = test))",
+		"CREATE INDEX idx_name ON foo (bar opclass)",
+		// Indexes created with ONLY are not supported
+		"CREATE INDEX idx_name ON ONLY foo (bar)",
+		// Indexes with NULLS NOT DISTINCT are not supported
+		"CREATE INDEX idx_name ON foo(a) NULLS NOT DISTINCT",
+		// IF NOT EXISTS is unsupported
+		"CREATE INDEX IF NOT EXISTS idx_name ON foo(a)",
+		// Indexes defined on expressions are not supported
+		"CREATE INDEX idx_name ON foo(LOWER(a))",
+		"CREATE INDEX idx_name ON foo(a, LOWER(b))",
+	}
+
+	for _, sql := range tests {
+		t.Run(sql, func(t *testing.T) {
+			ops, err := sql2pgroll.Convert(sql)
+			require.NoError(t, err)
+
+			require.Len(t, ops, 1)
+
+			assert.Equal(t, expect.RawSQLOp(sql), ops[0])
+		})
+	}
+}

pkg/sql2pgroll/expect/create_index.go

@@ -0,0 +1,67 @@
+// SPDX-License-Identifier: Apache-2.0
+
+package expect
+
+import (
+	"github.com/xataio/pgroll/pkg/migrations"
+)
+
+var CreateIndexOp1 = &migrations.OpCreateIndex{
+	Name:    "idx_name",
+	Table:   "foo",
+	Columns: []string{"bar"},
+	Method:  migrations.OpCreateIndexMethodBtree,
+}
+
+func CreateIndexOp1WithMethod(method string) *migrations.OpCreateIndex {
+	parsed, err := migrations.ParseCreateIndexMethod(method)
+	if err != nil {
+		panic(err)
+	}
+	return &migrations.OpCreateIndex{
+		Name:    "idx_name",
+		Table:   "foo",
+		Columns: []string{"bar"},
+		Method:  parsed,
+	}
+}
+
+var CreateIndexOp2 = &migrations.OpCreateIndex{
+	Name:    "idx_name",
+	Table:   "schema.foo",
+	Columns: []string{"bar"},
+	Method:  migrations.OpCreateIndexMethodBtree,
+}
+
+var CreateIndexOp3 = &migrations.OpCreateIndex{
+	Name:    "idx_name",
+	Table:   "foo",
+	Columns: []string{"bar", "baz"},
+	Method:  migrations.OpCreateIndexMethodBtree,
+}
+
+var CreateIndexOp4 = &migrations.OpCreateIndex{
+	Name:    "idx_name",
+	Table:   "foo",
+	Columns: []string{"bar"},
+	Method:  migrations.OpCreateIndexMethodBtree,
+	Unique:  true,
+}
+
+var CreateIndexOp5 = &migrations.OpCreateIndex{
+	Name:      "idx_name",
+	Table:     "foo",
+	Columns:   []string{"bar"},
+	Method:    migrations.OpCreateIndexMethodBtree,
+	Predicate: "foo > 0",
+}
+
+func CreateIndexOpWithStorageParam(param string) *migrations.OpCreateIndex {
+	return &migrations.OpCreateIndex{
+		Name:              "idx_name",
+		Table:             "foo",
+		Columns:           []string{"bar"},
+		Method:            migrations.OpCreateIndexMethodBtree,
+		StorageParameters: param,
+	}
+}