// getTableID retrieves the table ID for the specified table.
func getTableID(p *planner, tn *parser.TableName) (sqlbase.ID, error) {
if err := tn.QualifyWithDatabase(p.session.Database); err != nil {
return 0, err
}
virtual, err := p.session.virtualSchemas.getVirtualTableDesc(tn)
if err != nil {
return 0, err
}
if virtual != nil {
return virtual.GetID(), nil
}
dbID, err := p.getDatabaseID(tn.Database())
if err != nil {
return 0, err
}
nameKey := tableKey{dbID, tn.Table()}
key := nameKey.Key()
gr, err := p.txn.Get(key)
if err != nil {
return 0, err
}
if !gr.Exists() {
return 0, sqlbase.NewUndefinedTableError(parser.AsString(tn))
}
return sqlbase.ID(gr.ValueInt()), nil
}
// getVirtualTableEntry checks if the provided name matches a virtual database/table
// pair. The function will return the table's virtual table entry if the name matches
// a specific table. It will return an error if the name references a virtual database
// but the table is non-existent.
func (vs *virtualSchemaHolder) getVirtualTableEntry(
tn *parser.TableName,
) (virtualTableEntry, error) {
if db, ok := vs.getVirtualSchemaEntry(tn.DatabaseName.Normalize()); ok {
if t, ok := db.tables[tn.TableName.Normalize()]; ok {
return t, nil
}
return virtualTableEntry{}, sqlbase.NewUndefinedTableError(tn.String())
}
return virtualTableEntry{}, nil
}
// mustGetTableOrViewDesc implements the SchemaAccessor interface.
func (p *planner) mustGetTableOrViewDesc(tn *parser.TableName) (*sqlbase.TableDescriptor, error) {
desc, err := p.getTableOrViewDesc(tn)
if err != nil {
return nil, err
}
if desc == nil {
return nil, sqlbase.NewUndefinedTableError(tn.String())
}
if err := filterTableState(desc); err != nil {
return nil, err
}
return desc, nil
}
func mustGetTableDesc(
txn *client.Txn, vt VirtualTabler, tn *parser.TableName,
) (*sqlbase.TableDescriptor, error) {
desc, err := getTableDesc(txn, vt, tn)
if err != nil {
return nil, err
}
if desc == nil {
return nil, sqlbase.NewUndefinedTableError(tn.String())
}
if err := filterTableState(desc); err != nil {
return nil, err
}
return desc, nil
}
// getTableLeaseByID is a by-ID variant of getTableLease (i.e. uses same cache).
func (p *planner) getTableLeaseByID(tableID sqlbase.ID) (*sqlbase.TableDescriptor, error) {
if log.V(2) {
log.Infof(p.ctx(), "planner acquiring lease on table ID %d", tableID)
}
if testDisableTableLeases {
table, err := sqlbase.GetTableDescFromID(p.txn, tableID)
if err != nil {
return nil, err
}
if err := filterTableState(table); err != nil {
return nil, err
}
return table, nil
}
// First, look to see if we already have a lease for this table -- including
// leases acquired via `getTableLease`.
var lease *LeaseState
for _, l := range p.leases {
if l.ID == tableID {
lease = l
if log.V(2) {
log.Infof(p.ctx(), "found lease in planner cache for table %d", tableID)
}
break
}
}
// If we didn't find a lease or the lease is about to expire, acquire one.
if lease == nil || p.removeLeaseIfExpiring(lease) {
var err error
lease, err = p.leaseMgr.Acquire(p.txn, tableID, 0)
if err != nil {
if err == sqlbase.ErrDescriptorNotFound {
// Transform the descriptor error into an error that references the
// table's ID.
return nil, sqlbase.NewUndefinedTableError(fmt.Sprintf("<id=%d>", tableID))
}
return nil, err
}
p.leases = append(p.leases, lease)
// If the lease we just acquired expires before the txn's deadline, reduce
// the deadline.
p.txn.UpdateDeadlineMaybe(hlc.Timestamp{WallTime: lease.Expiration().UnixNano()})
}
return &lease.TableDescriptor, nil
}
// ShowGrants returns grant details for the specified objects and users.
// TODO(marc): implement no targets (meaning full scan).
// Privileges: None.
// Notes: postgres does not have a SHOW GRANTS statement.
// mysql only returns the user's privileges.
func (p *planner) ShowGrants(n *parser.ShowGrants) (planNode, error) {
if n.Targets == nil {
return nil, errors.Errorf("TODO(marc): implement SHOW GRANT with no targets")
}
objectType := "Database"
if n.Targets.Tables != nil {
objectType = "Table"
}
columns := ResultColumns{
{Name: objectType, Typ: parser.TypeString},
{Name: "User", Typ: parser.TypeString},
{Name: "Privileges", Typ: parser.TypeString},
}
return &delayedNode{
p: p,
name: "SHOW GRANTS",
columns: columns,
constructor: func(p *planner) (planNode, error) {
v := p.newContainerValuesNode(columns, 0)
// Check if the target exists.
checkFn := func(sql string, args ...interface{}) (bool, error) {
values, err := p.queryRowsAsRoot(sql, args...)
if err != nil {
return false, err
}
if len(values) > 0 {
return true, nil
}
return false, nil
}
queryFn := func(sql string, args ...interface{}) error {
rows, err := p.queryRows(sql, args...)
if err != nil {
return err
}
for _, r := range rows {
if _, err := v.rows.AddRow(r); err != nil {
return err
}
}
return nil
}
// Get grants of database from information_schema.schema_privileges
// if the type of target is database.
if n.Targets.Databases != nil {
// TODO(nvanbenschoten): Clean up parameter assignment throughout.
var params []interface{}
var paramHolders []string
paramSeq := 1
for _, db := range n.Targets.Databases.ToStrings() {
exists, err := checkFn(checkSchema, db)
if err != nil {
v.rows.Close()
return nil, err
}
if !exists {
v.rows.Close()
return nil, sqlbase.NewUndefinedDatabaseError(db)
}
paramHolders = append(paramHolders, fmt.Sprintf("$%d", paramSeq))
paramSeq++
params = append(params, db)
}
schemaGrants := fmt.Sprintf(`SELECT TABLE_SCHEMA AS "Database", GRANTEE AS "User",
PRIVILEGE_TYPE AS "Privileges" FROM information_schema.schema_privileges
WHERE TABLE_SCHEMA IN (%s)`, strings.Join(paramHolders, ","))
if n.Grantees != nil {
paramHolders = paramHolders[:0]
for _, grantee := range n.Grantees.ToStrings() {
paramHolders = append(paramHolders, fmt.Sprintf("$%d", paramSeq))
params = append(params, grantee)
paramSeq++
}
schemaGrants = fmt.Sprintf(`%s AND GRANTEE IN(%s)`, schemaGrants, strings.Join(paramHolders, ","))
}
if err := queryFn(schemaGrants, params...); err != nil {
v.rows.Close()
return nil, err
}
}
// Get grants of table from information_schema.table_privileges
// if the type of target is table.
if n.Targets.Tables != nil {
// TODO(nvanbenschoten): Clean up parameter assignment throughout.
var params []interface{}
var paramHolders []string
paramSeq := 1
for _, tableTarget := range n.Targets.Tables {
tableGlob, err := tableTarget.NormalizeTablePattern()
if err != nil {
v.rows.Close()
return nil, err
}
tables, err := p.expandTableGlob(tableGlob)
if err != nil {
v.rows.Close()
return nil, err
}
for i := range tables {
exists, err := checkFn(checkTable, tables[i].Database(), tables[i].Table())
if err != nil {
v.rows.Close()
return nil, err
}
if !exists {
v.rows.Close()
return nil, sqlbase.NewUndefinedTableError(tables[i].String())
}
paramHolders = append(paramHolders, fmt.Sprintf("($%d,$%d)",
paramSeq, paramSeq+1))
params = append(params, tables[i].Database(), tables[i].Table())
paramSeq += 2
}
}
tableGrants := fmt.Sprintf(`SELECT TABLE_NAME, GRANTEE, PRIVILEGE_TYPE FROM information_schema.table_privileges
WHERE (TABLE_SCHEMA, TABLE_NAME) IN (%s)`, strings.Join(paramHolders, ","))
if n.Grantees != nil {
paramHolders = paramHolders[:0]
for _, grantee := range n.Grantees.ToStrings() {
paramHolders = append(paramHolders, fmt.Sprintf("$%d", paramSeq))
params = append(params, grantee)
paramSeq++
}
tableGrants = fmt.Sprintf(`%s AND GRANTEE IN(%s)`, tableGrants, strings.Join(paramHolders, ","))
}
if err := queryFn(tableGrants, params...); err != nil {
v.rows.Close()
return nil, err
}
}
// Sort the result by target name, user name and privileges.
sort := &sortNode{
ctx: p.ctx(),
p: p,
ordering: sqlbase.ColumnOrdering{
{ColIdx: 0, Direction: encoding.Ascending},
{ColIdx: 1, Direction: encoding.Ascending},
{ColIdx: 2, Direction: encoding.Ascending},
},
columns: v.columns,
}
return &selectTopNode{source: v, sort: sort}, nil
},
}, nil
}
// ShowColumns of a table.
// Privileges: Any privilege on table.
// Notes: postgres does not have a SHOW COLUMNS statement.
// mysql only returns columns you have privileges on.
func (p *planner) ShowColumns(n *parser.ShowColumns) (planNode, error) {
tn, err := n.Table.NormalizeWithDatabaseName(p.session.Database)
if err != nil {
return nil, err
}
columns := ResultColumns{
{Name: "Field", Typ: parser.TypeString},
{Name: "Type", Typ: parser.TypeString},
{Name: "Null", Typ: parser.TypeBool},
{Name: "Default", Typ: parser.TypeString},
}
return &delayedNode{
p: p,
name: "SHOW COLUMNS FROM " + tn.String(),
columns: columns,
constructor: func(p *planner) (planNode, error) {
const getColumns = `SELECT COLUMN_NAME AS "Field", DATA_TYPE AS "Type", (IS_NULLABLE!='NO') AS "Null",` +
` COLUMN_DEFAULT AS "Default" FROM information_schema.columns WHERE TABLE_SCHEMA=$1 AND TABLE_NAME=$2` +
` ORDER BY ORDINAL_POSITION`
{
// Check if the database exists by using the security.RootUser.
values, err := p.queryRowsAsRoot(checkSchema, tn.Database())
if err != nil {
return nil, err
}
if len(values) == 0 {
return nil, sqlbase.NewUndefinedDatabaseError(tn.Database())
}
}
{
// Check if the table exists by using the security.RootUser.
values, err := p.queryRowsAsRoot(checkTable, tn.Database(), tn.Table())
if err != nil {
return nil, err
}
if len(values) == 0 {
return nil, sqlbase.NewUndefinedTableError(tn.String())
}
}
// Check if the user has been granted.
// Skip the checking if the table is a virtual table.
{
virDesc, err := p.session.virtualSchemas.getVirtualTableDesc(tn)
if err != nil {
return nil, err
}
if virDesc == nil {
values, err := p.QueryRow(checkTablePrivilege, tn.Database(), tn.Table(), p.session.User)
if err != nil {
return nil, err
}
if len(values) == 0 {
return nil, fmt.Errorf("user %s has no privileges on table %s", p.session.User, tn.String())
}
}
}
// Temporarily set the current database to get visibility into
// information_schema if the current user isn't root.
origDatabase := p.evalCtx.Database
p.evalCtx.Database = tn.Database()
defer func() { p.evalCtx.Database = origDatabase }()
// Get columns of table from information_schema.columns.
rows, err := p.queryRows(getColumns, tn.Database(), tn.Table())
if err != nil {
return nil, err
}
v := p.newContainerValuesNode(columns, 0)
for _, r := range rows {
if _, err := v.rows.AddRow(r); err != nil {
v.rows.Close()
return nil, err
}
}
return v, nil
},
}, nil
}
// getTableLease implements the SchemaAccessor interface.
func (p *planner) getTableLease(tn *parser.TableName) (*sqlbase.TableDescriptor, error) {
if log.V(2) {
log.Infof(p.ctx(), "planner acquiring lease on table '%s'", tn)
}
isSystemDB := tn.Database() == sqlbase.SystemDB.Name
isVirtualDB := p.session.virtualSchemas.isVirtualDatabase(tn.Database())
if isSystemDB || isVirtualDB || testDisableTableLeases {
// We don't go through the normal lease mechanism for:
// - system tables. The system.lease and system.descriptor table, in
// particular, are problematic because they are used for acquiring
// leases itself, creating a chicken&egg problem.
// - virtual tables. These tables' descriptors are not persisted,
// so they cannot be leased. Instead, we simply return the static
// descriptor and rely on the immutability privileges set on the
// descriptors to cause upper layers to reject mutations statements.
tbl, err := p.mustGetTableDesc(tn)
if err != nil {
return nil, err
}
if err := filterTableState(tbl); err != nil {
return nil, err
}
return tbl, nil
}
dbID, err := p.getDatabaseID(tn.Database())
if err != nil {
return nil, err
}
// First, look to see if we already have a lease for this table.
// This ensures that, once a SQL transaction resolved name N to id X, it will
// continue to use N to refer to X even if N is renamed during the
// transaction.
var lease *LeaseState
for _, l := range p.leases {
if parser.ReNormalizeName(l.Name) == tn.TableName.Normalize() &&
l.ParentID == dbID {
lease = l
if log.V(2) {
log.Infof(p.ctx(), "found lease in planner cache for table '%s'", tn)
}
break
}
}
// If we didn't find a lease or the lease is about to expire, acquire one.
if lease == nil || p.removeLeaseIfExpiring(lease) {
var err error
lease, err = p.leaseMgr.AcquireByName(p.txn, dbID, tn.Table())
if err != nil {
if err == sqlbase.ErrDescriptorNotFound {
// Transform the descriptor error into an error that references the
// table's name.
return nil, sqlbase.NewUndefinedTableError(tn.String())
}
return nil, err
}
p.leases = append(p.leases, lease)
if log.V(2) {
log.Infof(p.ctx(), "added lease on table '%s' to planner cache", tn)
}
// If the lease we just acquired expires before the txn's deadline, reduce
// the deadline.
p.txn.UpdateDeadlineMaybe(hlc.Timestamp{WallTime: lease.Expiration().UnixNano()})
}
return &lease.TableDescriptor, nil
}
// RenameTable renames the table or view.
// Privileges: DROP on source table/view, CREATE on destination database.
// Notes: postgres requires the table owner.
// mysql requires ALTER, DROP on the original table, and CREATE, INSERT
// on the new table (and does not copy privileges over).
func (p *planner) RenameTable(n *parser.RenameTable) (planNode, error) {
oldTn, err := n.Name.NormalizeWithDatabaseName(p.session.Database)
if err != nil {
return nil, err
}
newTn, err := n.NewName.NormalizeWithDatabaseName(p.session.Database)
if err != nil {
return nil, err
}
dbDesc, err := p.mustGetDatabaseDesc(oldTn.Database())
if err != nil {
return nil, err
}
// Check if source table or view exists.
// Note that Postgres's behavior here is a little lenient - it'll let you
// modify views by running ALTER TABLE, but won't let you modify tables
// by running ALTER VIEW. Our behavior is strict for now, but can be
// made more lenient down the road if needed.
var tableDesc *sqlbase.TableDescriptor
if n.IsView {
tableDesc, err = p.getViewDesc(oldTn)
if err != nil {
return nil, err
}
if tableDesc == nil {
if n.IfExists {
// Noop.
return &emptyNode{}, nil
}
// Key does not exist, but we want it to: error out.
return nil, sqlbase.NewUndefinedViewError(oldTn.String())
}
if tableDesc.State != sqlbase.TableDescriptor_PUBLIC {
return nil, sqlbase.NewUndefinedViewError(oldTn.String())
}
} else {
tableDesc, err = p.getTableDesc(oldTn)
if err != nil {
return nil, err
}
if tableDesc == nil {
if n.IfExists {
// Noop.
return &emptyNode{}, nil
}
// Key does not exist, but we want it to: error out.
return nil, sqlbase.NewUndefinedTableError(oldTn.String())
}
if tableDesc.State != sqlbase.TableDescriptor_PUBLIC {
return nil, sqlbase.NewUndefinedTableError(oldTn.String())
}
}
if err := p.checkPrivilege(tableDesc, privilege.DROP); err != nil {
return nil, err
}
// Check if any views depend on this table/view. Because our views
// are currently just stored as strings, they explicitly specify the name
// of everything they depend on. Rather than trying to rewrite the view's
// query with the new name, we simply disallow such renames for now.
if len(tableDesc.DependedOnBy) > 0 {
return nil, p.dependentViewRenameError(
tableDesc.TypeName(), oldTn.String(), tableDesc.ParentID, tableDesc.DependedOnBy[0].ID)
}
// Check if target database exists.
targetDbDesc, err := p.mustGetDatabaseDesc(newTn.Database())
if err != nil {
return nil, err
}
if err := p.checkPrivilege(targetDbDesc, privilege.CREATE); err != nil {
return nil, err
}
// oldTn and newTn are already normalized, so we can compare directly here.
if oldTn.Database() == newTn.Database() && oldTn.Table() == newTn.Table() {
// Noop.
return &emptyNode{}, nil
}
tableDesc.SetName(newTn.Table())
tableDesc.ParentID = targetDbDesc.ID
descKey := sqlbase.MakeDescMetadataKey(tableDesc.GetID())
newTbKey := tableKey{targetDbDesc.ID, newTn.Table()}.Key()
if err := tableDesc.Validate(p.txn); err != nil {
return nil, err
}
descID := tableDesc.GetID()
descDesc := sqlbase.WrapDescriptor(tableDesc)
if err := tableDesc.SetUpVersion(); err != nil {
return nil, err
}
renameDetails := sqlbase.TableDescriptor_RenameInfo{
OldParentID: dbDesc.ID,
OldName: oldTn.Table()}
tableDesc.Renames = append(tableDesc.Renames, renameDetails)
if err := p.writeTableDesc(tableDesc); err != nil {
return nil, err
}
// We update the descriptor to the new name, but also leave the mapping of the
// old name to the id, so that the name is not reused until the schema changer
// has made sure it's not in use any more.
b := &client.Batch{}
b.Put(descKey, descDesc)
b.CPut(newTbKey, descID, nil)
if err := p.txn.Run(b); err != nil {
if _, ok := err.(*roachpb.ConditionFailedError); ok {
return nil, sqlbase.NewRelationAlreadyExistsError(newTn.Table())
}
return nil, err
}
p.notifySchemaChange(tableDesc.ID, sqlbase.InvalidMutationID)
p.setTestingVerifyMetadata(func(systemConfig config.SystemConfig) error {
if err := expectDescriptorID(systemConfig, newTbKey, descID); err != nil {
return err
}
if err := expectDescriptor(systemConfig, descKey, descDesc); err != nil {
return err
}
return nil
})
return &emptyNode{}, nil
}