// 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 := 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 getVirtualTableEntry(tn *parser.TableName) (virtualTableEntry, error) { if db, ok := getVirtualSchemaEntry(tn.Database()); ok { if t, ok := db.tables[sqlbase.NormalizeName(tn.TableName)]; ok { return t, nil } return virtualTableEntry{}, sqlbase.NewUndefinedTableError(tn.String()) } return virtualTableEntry{}, nil }
// getTableDesc implements the SchemaAccessor interface. func (p *planner) getTableDesc(tn *parser.TableName) (*sqlbase.TableDescriptor, error) { virtual, err := getVirtualTableDesc(tn) if err != nil || virtual != nil { return virtual, err } dbDesc, err := p.mustGetDatabaseDesc(tn.Database()) if err != nil { return nil, err } desc := sqlbase.TableDescriptor{} found, err := p.getDescriptor(tableKey{parentID: dbDesc.ID, name: tn.Table()}, &desc) if err != nil { return nil, err } if !found { return nil, nil } return &desc, 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 := 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 sqlbase.ReNormalizeName(l.Name) == sqlbase.NormalizeName(tn.TableName) && l.ParentID == dbID { lease = l if log.V(2) { log.Infof(p.ctx(), "found lease in planner cache for table %q", 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 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 }