// 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)
}
dbID, pErr := p.getDatabaseID(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{dbID, 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) (ID, error) {
if err := qname.NormalizeTableName(p.session.Database); err != nil {
return 0, 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, err := p.getCachedDatabaseDesc(qname.Database())
if err != nil {
dbDesc, err = p.getDatabaseDesc(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.
nameKey := tableKey{dbDesc.ID, qname.Table()}
key := nameKey.Key()
if nameVal := p.systemConfig.GetValue(key); nameVal != nil {
id, err := nameVal.GetInt()
return ID(id), err
}
gr, err := p.txn.Get(key)
if err != nil {
return 0, err
}
if !gr.Exists() {
return 0, fmt.Errorf("table %q does not exist", nameKey.Name())
}
return ID(gr.ValueInt()), nil
}
// 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
}
// 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
}
// 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 nil, 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.
return p.mustGetTableDesc(qname)
}
dbID, err := p.getDatabaseID(qname.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 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 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, qname.Table())
if err != nil {
if err == errDescriptorNotFound {
// Transform the descriptor error into an error that references the
// table's name.
return nil, sqlbase.NewUndefinedTableError(qname.String())
}
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
}
// 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 (p *planner) getTableDesc(qname *parser.QualifiedName) (*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
}
desc := TableDescriptor{}
if err := p.getDescriptor(tableKey{dbDesc.ID, qname.Table()}, &desc); err != nil {
return nil, err
}
return &desc, nil
}
func (p *planner) getTableDesc(qname *parser.QualifiedName) (TableDescriptor, *roachpb.Error) {
if err := qname.NormalizeTableName(p.session.Database); err != nil {
return TableDescriptor{}, roachpb.NewError(err)
}
dbDesc, pErr := p.getDatabaseDesc(qname.Database())
if pErr != nil {
return TableDescriptor{}, pErr
}
desc := TableDescriptor{}
if pErr := p.getDescriptor(tableKey{dbDesc.ID, qname.Table()}, &desc); pErr != nil {
return TableDescriptor{}, pErr
}
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
}
// 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
}
// 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
}
// 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
}