// getTableLease acquires a lease for the specified table. The lease will be
// released when the planner closes.
func (p *planner) getTableLease(qname *parser.QualifiedName) (*TableDescriptor, *roachpb.Error) {
if err := qname.NormalizeTableName(p.session.Database); err != nil {
return nil, roachpb.NewError(err)
}
if qname.Database() == systemDB.Name || 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.
return p.getTableDesc(qname)
}
tableID, pErr := p.getTableID(qname)
if pErr != nil {
return nil, pErr
}
if p.leases == nil {
p.leases = make(map[ID]*LeaseState)
}
lease, ok := p.leases[tableID]
if !ok {
var pErr *roachpb.Error
lease, pErr = p.leaseMgr.Acquire(p.txn, tableID, 0)
if pErr != nil {
return nil, pErr
}
p.leases[tableID] = lease
}
return proto.Clone(&lease.TableDescriptor).(*TableDescriptor), nil
}
func (s *Server) getTableDesc(database string, qname parser.QualifiedName) (
*structured.TableDescriptor, error) {
var err error
qname, err = s.normalizeTableName(database, qname)
if err != nil {
return nil, err
}
dbID, err := s.lookupDatabase(qname.Database())
if err != nil {
return nil, err
}
gr, err := s.db.Get(keys.MakeNameMetadataKey(dbID, qname.Table()))
if err != nil {
return nil, err
}
if !gr.Exists() {
return nil, fmt.Errorf("table \"%s\" does not exist", qname)
}
descKey := gr.ValueBytes()
desc := structured.TableDescriptor{}
if err := s.db.GetProto(descKey, &desc); err != nil {
return nil, err
}
if err := desc.Validate(); err != nil {
return nil, err
}
return &desc, nil
}
// expandTableGlob expands wildcards from the end of `expr` and
// returns the list of matching tables.
// `expr` is possibly modified to be qualified with the database it refers to.
// `expr` is assumed to be of one of several forms:
// database.table
// table
// *
func (p *planner) expandTableGlob(expr *parser.QualifiedName) (
parser.QualifiedNames, *roachpb.Error) {
if len(expr.Indirect) == 0 {
return parser.QualifiedNames{expr}, nil
}
if err := expr.QualifyWithDatabase(p.session.Database); err != nil {
return nil, roachpb.NewError(err)
}
// We must have a single indirect: either .table or .*
if len(expr.Indirect) != 1 {
return nil, roachpb.NewErrorf("invalid table glob: %s", expr)
}
switch expr.Indirect[0].(type) {
case parser.NameIndirection:
return parser.QualifiedNames{expr}, nil
case parser.StarIndirection:
dbDesc, pErr := p.getDatabaseDesc(string(expr.Base))
if pErr != nil {
return nil, pErr
}
tableNames, pErr := p.getTableNames(dbDesc)
if pErr != nil {
return nil, pErr
}
return tableNames, nil
default:
return nil, roachpb.NewErrorf("invalid table glob: %s", expr)
}
}
// mustGetTableDesc implements the SchemaAccessor interface.
func (p *planner) mustGetTableDesc(qname *parser.QualifiedName) (*sqlbase.TableDescriptor, error) {
desc, err := p.getTableDesc(qname)
if err != nil {
return nil, err
}
if desc == nil {
return nil, sqlbase.NewUndefinedTableError(qname.String())
}
return desc, nil
}
// Initializes a scanNode with a tableName. Returns the table or index name that can be used for
// fully-qualified columns if an alias is not specified.
func (n *scanNode) initTable(p *planner, tableName *parser.QualifiedName) (string, *roachpb.Error) {
if n.desc, n.pErr = p.getTableLease(tableName); n.pErr != nil {
return "", n.pErr
}
if err := p.checkPrivilege(&n.desc, privilege.SELECT); err != nil {
return "", roachpb.NewError(err)
}
alias := n.desc.Name
indexName := tableName.Index()
if indexName != "" && !equalName(n.desc.PrimaryIndex.Name, indexName) {
for i := range n.desc.Indexes {
if equalName(n.desc.Indexes[i].Name, indexName) {
// Remove all but the matching index from the descriptor.
n.desc.Indexes = n.desc.Indexes[i : i+1]
n.index = &n.desc.Indexes[0]
break
}
}
if n.index == nil {
n.pErr = roachpb.NewUErrorf("index \"%s\" not found", indexName)
return "", n.pErr
}
// Use the index name instead of the table name for fully-qualified columns in the
// expression.
alias = n.index.Name
// Strip out any columns from the table that are not present in the
// index.
visibleCols := make([]ColumnDescriptor, 0, len(n.index.ColumnIDs)+len(n.index.ImplicitColumnIDs))
for _, colID := range n.index.ColumnIDs {
col, err := n.desc.FindColumnByID(colID)
n.pErr = roachpb.NewError(err)
if n.pErr != nil {
return "", n.pErr
}
visibleCols = append(visibleCols, *col)
}
for _, colID := range n.index.ImplicitColumnIDs {
col, err := n.desc.FindColumnByID(colID)
n.pErr = roachpb.NewError(err)
if n.pErr != nil {
return "", n.pErr
}
visibleCols = append(visibleCols, *col)
}
n.isSecondaryIndex = true
n.initVisibleCols(visibleCols, len(n.index.ImplicitColumnIDs))
} else {
n.initDescDefaults()
}
return alias, nil
}
// Initializes a scanNode with a tableName. Returns the table or index name that can be used for
// fully-qualified columns if an alias is not specified.
func (n *scanNode) initTable(
p *planner,
tableName *parser.QualifiedName,
indexHints *parser.IndexHints,
scanVisibility scanVisibility,
) (string, error) {
var err error
// AS OF SYSTEM TIME queries need to fetch the table descriptor at the
// specified time, and never lease anything. The proto transaction already
// has its timestamps set correctly so getTableDesc will fetch with the
// correct timestamp.
if p.asOf {
desc, err := p.getTableDesc(tableName)
if err != nil {
return "", err
}
if desc == nil {
return "", sqlbase.NewUndefinedTableError(tableName.String())
}
n.desc = *desc
} else {
n.desc, err = p.getTableLease(tableName)
}
if err != nil {
return "", err
}
if err := p.checkPrivilege(&n.desc, privilege.SELECT); err != nil {
return "", err
}
alias := n.desc.Name
if indexHints != nil && indexHints.Index != "" {
indexName := sqlbase.NormalizeName(string(indexHints.Index))
if indexName == sqlbase.NormalizeName(n.desc.PrimaryIndex.Name) {
n.specifiedIndex = &n.desc.PrimaryIndex
} else {
for i := range n.desc.Indexes {
if indexName == sqlbase.NormalizeName(n.desc.Indexes[i].Name) {
n.specifiedIndex = &n.desc.Indexes[i]
break
}
}
if n.specifiedIndex == nil {
return "", fmt.Errorf("index \"%s\" not found", indexName)
}
}
}
n.noIndexJoin = (indexHints != nil && indexHints.NoIndexJoin)
n.initDescDefaults(scanVisibility)
return alias, nil
}
func (p *planner) normalizeTableName(qname *parser.QualifiedName) error {
if qname == nil || qname.Base == "" {
return fmt.Errorf("empty table name: %s", qname)
}
if len(qname.Indirect) == 0 {
if p.session.Database == "" {
return fmt.Errorf("no database specified")
}
qname.Indirect = append(qname.Indirect, parser.NameIndirection(qname.Base))
qname.Base = parser.Name(p.session.Database)
}
return nil
}
// getTableID retrieves the table ID for the specified table. It uses the
// descriptor cache to perform lookups, falling back to the KV store when
// necessary.
func (p *planner) getTableID(qname *parser.QualifiedName) (ID, *roachpb.Error) {
if err := qname.NormalizeTableName(p.session.Database); err != nil {
return 0, roachpb.NewError(err)
}
// Lookup the database in the cache first, falling back to the KV store if it
// isn't present. The cache might cause the usage of a recently renamed
// database, but that's a race that could occur anyways.
dbDesc, pErr := p.getCachedDatabaseDesc(qname.Database())
if pErr != nil {
dbDesc, pErr = p.getDatabaseDesc(qname.Database())
if pErr != nil {
return 0, pErr
}
}
// Lookup the ID of the table in the cache. The use of the cache might cause
// the usage of a recently renamed table, but that's a race that could occur
// anyways.
nameKey := tableKey{dbDesc.ID, qname.Table()}
key := nameKey.Key()
if nameVal := p.systemConfig.GetValue(key); nameVal != nil {
id, err := nameVal.GetInt()
return ID(id), roachpb.NewError(err)
}
gr, pErr := p.txn.Get(key)
if pErr != nil {
return 0, pErr
}
if !gr.Exists() {
return 0, roachpb.NewErrorf("table %q does not exist", nameKey.Name())
}
return ID(gr.ValueInt()), nil
}
// getTableID retrieves the table ID for the specified table. It uses the
// descriptor cache to perform lookups, falling back to the KV store when
// necessary.
func (p *planner) getTableID(qname *parser.QualifiedName) (sqlbase.ID, error) {
if err := qname.NormalizeTableName(p.session.Database); err != nil {
return 0, err
}
dbID, err := p.getDatabaseID(qname.Database())
if err != nil {
return 0, err
}
// Lookup the ID of the table in the cache. The use of the cache might cause
// the usage of a recently renamed table, but that's a race that could occur
// anyways.
// TODO(andrei): remove the used of p.systemConfig as a cache for table names,
// replace it with using the leases for resolving names, and do away with any
// races due to renames. We'll probably have to rewrite renames to perform
// an async schema change.
nameKey := tableKey{dbID, qname.Table()}
key := nameKey.Key()
if nameVal := p.systemConfig.GetValue(key); nameVal != nil {
id, err := nameVal.GetInt()
return sqlbase.ID(id), err
}
gr, err := p.txn.Get(key)
if err != nil {
return 0, err
}
if !gr.Exists() {
return 0, tableDoesNotExistError(qname.String())
}
return sqlbase.ID(gr.ValueInt()), nil
}
func (p *planner) getTableDesc(qname *parser.QualifiedName) (
*structured.TableDescriptor, error) {
if err := p.normalizeTableName(qname); err != nil {
return nil, err
}
dbDesc, err := p.getDatabaseDesc(qname.Database())
if err != nil {
return nil, err
}
desc := structured.TableDescriptor{}
if err := p.getDescriptor(tableKey{dbDesc.ID, qname.Table()}, &desc); err != nil {
return nil, err
}
return &desc, nil
}
// findColumn looks up the column described by a QualifiedName. The qname will be normalized.
func (qt qvalResolver) findColumn(qname *parser.QualifiedName) (columnRef, error) {
ref := columnRef{colIdx: invalidColIdx}
if err := qname.NormalizeColumnName(); err != nil {
return ref, err
}
// We can't resolve stars to a single column.
if qname.IsStar() {
err := fmt.Errorf("qualified name \"%s\" not found", qname)
return ref, err
}
// TODO(radu): when we support multiple FROMs, we will find the node with the correct alias; if
// no alias is given, we will search for the column in all FROMs and make sure there is only
// one. For now we just check that the name matches (if given).
if qname.Base == "" {
qname.Base = parser.Name(qt.table.alias)
}
if equalName(qt.table.alias, string(qname.Base)) {
colName := qname.Column()
for idx, col := range qt.table.columns {
if equalName(col.Name, colName) {
ref.table = qt.table
ref.colIdx = idx
return ref, nil
}
}
}
err := fmt.Errorf("qualified name \"%s\" not found", qname)
return ref, err
}
// findColumn looks up the column described by a QualifiedName. The qname will be normalized.
func (qt qvalResolver) findColumn(qname *parser.QualifiedName) (columnRef, error) {
ref := columnRef{colIdx: invalidColIdx}
if err := qname.NormalizeColumnName(); err != nil {
return ref, err
}
// We can't resolve stars to a single column.
if qname.IsStar() {
err := fmt.Errorf("qualified name \"%s\" not found", qname)
return ref, err
}
colName := sqlbase.NormalizeName(qname.Column())
for _, table := range qt.tables {
if qname.Base == "" || sqlbase.EqualName(table.alias, string(qname.Base)) {
for idx, col := range table.columns {
if sqlbase.NormalizeName(col.Name) == colName {
if ref.colIdx != invalidColIdx {
return ref, fmt.Errorf("column reference \"%s\" is ambiguous", qname)
}
ref.table = table
ref.colIdx = idx
}
}
}
}
if ref.colIdx == invalidColIdx {
return ref, fmt.Errorf("qualified name \"%s\" not found", qname)
}
return ref, nil
}
// getTableLease acquires a lease for the specified table. The lease will be
// released when the planner closes. Note that a shallow copy of the table
// descriptor is returned. It is safe to mutate fields of the returned
// descriptor, but the values those fields point to should not be modified.
func (p *planner) getTableLease(qname *parser.QualifiedName) (sqlbase.TableDescriptor, error) {
if err := qname.NormalizeTableName(p.session.Database); err != nil {
return sqlbase.TableDescriptor{}, err
}
if qname.Database() == sqlbase.SystemDB.Name || 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.
desc, err := p.getTableDesc(qname)
if err != nil {
return sqlbase.TableDescriptor{}, err
}
if desc == nil {
return sqlbase.TableDescriptor{}, tableDoesNotExistError(qname.String())
}
return *desc, nil
}
tableID, err := p.getTableID(qname)
if err != nil {
return sqlbase.TableDescriptor{}, err
}
var lease *LeaseState
var commitBy time.Time
for _, l := range p.leases {
commitBy = updateCommitBy(commitBy, l)
if l.TableDescriptor.ID == tableID {
lease = l
}
}
if lease == nil {
var err error
lease, err = p.leaseMgr.Acquire(p.txn, tableID, 0)
if err != nil {
if _, ok := err.(*roachpb.DescriptorNotFoundError); ok {
// Transform the descriptor error into an error that references the
// table's name.
return sqlbase.TableDescriptor{}, tableDoesNotExistError(qname.String())
}
return sqlbase.TableDescriptor{}, err
}
p.leases = append(p.leases, lease)
commitBy = updateCommitBy(commitBy, lease)
}
p.txn.SetDeadline(roachpb.Timestamp{WallTime: commitBy.UnixNano()})
return lease.TableDescriptor, nil
}
func (v *qnameVisitor) getDesc(qname *parser.QualifiedName) *TableDescriptor {
if v.desc == nil {
return nil
}
if qname.Base == "" {
qname.Base = parser.Name(v.desc.Alias)
return v.desc
}
if equalName(v.desc.Alias, string(qname.Base)) {
return v.desc
}
return nil
}
// getTableLease acquires a lease for the specified table. The lease will be
// released when the planner closes. Note that a shallow copy of the table
// descriptor is returned. It is safe to mutate fields of the returned
// descriptor, but the values those fields point to should not be modified.
//
// TODO(pmattis): Return a TableDesriptor value instead of a pointer.
func (p *planner) getTableLease(qname *parser.QualifiedName) (*TableDescriptor, *roachpb.Error) {
if err := qname.NormalizeTableName(p.session.Database); err != nil {
return nil, roachpb.NewError(err)
}
if qname.Database() == systemDB.Name || 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.
return p.getTableDesc(qname)
}
tableID, pErr := p.getTableID(qname)
if pErr != nil {
return nil, pErr
}
var lease *LeaseState
found := false
for _, lease = range p.leases {
if lease.TableDescriptor.ID == tableID {
found = true
break
}
}
if !found {
var pErr *roachpb.Error
lease, pErr = p.leaseMgr.Acquire(p.txn, tableID, 0)
if pErr != nil {
return nil, pErr
}
p.leases = append(p.leases, lease)
}
desc := &TableDescriptor{}
*desc = lease.TableDescriptor
return desc, nil
}
// getTableID retrieves the table ID for the specified table.
func getTableID(p *planner, qname *parser.QualifiedName) (sqlbase.ID, error) {
if err := qname.NormalizeTableName(p.session.Database); err != nil {
return 0, err
}
dbID, err := p.getDatabaseID(qname.Database())
if err != nil {
return 0, err
}
nameKey := tableKey{dbID, qname.Table()}
key := nameKey.Key()
gr, err := p.txn.Get(key)
if err != nil {
return 0, err
}
if !gr.Exists() {
return 0, sqlbase.NewUndefinedTableError(qname.String())
}
return sqlbase.ID(gr.ValueInt()), nil
}
// getTableDesc implements the SchemaAccessor interface.
func (p *planner) getTableDesc(qname *parser.QualifiedName) (*sqlbase.TableDescriptor, error) {
if err := qname.NormalizeTableName(p.session.Database); err != nil {
return nil, err
}
dbDesc, err := p.getDatabaseDesc(qname.Database())
if err != nil {
return nil, err
}
if dbDesc == nil {
return nil, sqlbase.NewUndefinedDatabaseError(qname.Database())
}
desc := sqlbase.TableDescriptor{}
found, err := p.getDescriptor(tableKey{parentID: dbDesc.ID, name: qname.Table()}, &desc)
if err != nil {
return nil, err
}
if !found {
return nil, nil
}
return &desc, nil
}
func (p *planner) getTableDesc(qname *parser.QualifiedName) (*TableDescriptor, *roachpb.Error) {
if err := qname.NormalizeTableName(p.session.Database); err != nil {
return nil, roachpb.NewError(err)
}
dbDesc, pErr := p.getDatabaseDesc(qname.Database())
if pErr != nil {
return nil, pErr
}
desc := TableDescriptor{}
if pErr := p.getDescriptor(tableKey{dbDesc.ID, qname.Table()}, &desc); pErr != nil {
return nil, pErr
}
return &desc, nil
}
// getCachedTableDesc looks for a table descriptor in the descriptor cache.
// Looks up the database descriptor, followed by the table descriptor.
//
// Returns: the table descriptor, whether it comes from the cache, and an error.
func (p *planner) getCachedTableDesc(qname *parser.QualifiedName) (*TableDescriptor, bool, error) {
if err := qname.NormalizeTableName(p.session.Database); err != nil {
return nil, false, err
}
dbDesc, cached, err := p.getCachedDatabaseDesc(qname.Database())
if err != nil {
return nil, false, err
}
desc := &TableDescriptor{}
// Only attempt cached lookup if the database descriptor was found in the cache.
if cached {
if err := p.getCachedDescriptor(tableKey{dbDesc.ID, qname.Table()}, desc); err == nil {
return desc, true, nil
}
// Problem, or not found in the cache: fall back on KV lookup.
}
if err := p.getDescriptor(tableKey{dbDesc.ID, qname.Table()}, desc); err != nil {
return nil, false, err
}
return desc, false, nil
}
// getTableLease implements the SchemaAccessor interface.
func (p *planner) getTableLease(qname *parser.QualifiedName) (sqlbase.TableDescriptor, error) {
if log.V(2) {
log.Infof("planner acquiring lease on table %q", qname)
}
if err := qname.NormalizeTableName(p.session.Database); err != nil {
return sqlbase.TableDescriptor{}, err
}
if qname.Database() == sqlbase.SystemDB.Name || 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.
desc, err := p.getTableDesc(qname)
if err != nil {
return sqlbase.TableDescriptor{}, err
}
if desc == nil {
return sqlbase.TableDescriptor{}, sqlbase.NewUndefinedTableError(qname.String())
}
return *desc, nil
}
if err := qname.NormalizeTableName(p.session.Database); err != nil {
return sqlbase.TableDescriptor{}, err
}
dbID, err := p.getDatabaseID(qname.Database())
if err != nil {
return sqlbase.TableDescriptor{}, 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 sqlbase.NormalizeName(l.Name) == sqlbase.NormalizeName(qname.Table()) &&
l.ParentID == dbID {
lease = l
if log.V(2) {
log.Infof("found lease in planner cache for table %q", qname)
}
break
}
}
// If we didn't find a lease, acquire one.
if lease == nil {
var err error
lease, err = p.leaseMgr.AcquireByName(p.txn, dbID, qname.Table())
if err != nil {
if err == errDescriptorNotFound {
// Transform the descriptor error into an error that references the
// table's name.
return sqlbase.TableDescriptor{}, sqlbase.NewUndefinedTableError(qname.String())
}
return sqlbase.TableDescriptor{}, 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(roachpb.Timestamp{WallTime: lease.Expiration().UnixNano()})
}
return lease.TableDescriptor, nil
}
