Пример #1
0
// getTableNames implements the SchemaAccessor interface.
func (p *planner) getTableNames(dbDesc *sqlbase.DatabaseDescriptor) (parser.TableNames, error) {
	if e, ok := p.session.virtualSchemas.getVirtualSchemaEntry(dbDesc.Name); ok {
		return e.tableNames(), nil
	}

	prefix := sqlbase.MakeNameMetadataKey(dbDesc.ID, "")
	sr, err := p.txn.Scan(prefix, prefix.PrefixEnd(), 0)
	if err != nil {
		return nil, err
	}

	var tableNames parser.TableNames
	for _, row := range sr {
		_, tableName, err := encoding.DecodeUnsafeStringAscending(
			bytes.TrimPrefix(row.Key, prefix), nil)
		if err != nil {
			return nil, err
		}
		tn := parser.TableName{
			DatabaseName: parser.Name(dbDesc.Name),
			TableName:    parser.Name(tableName),
		}
		tableNames = append(tableNames, tn)
	}
	return tableNames, nil
}
Пример #2
0
// ShowDatabases returns all the databases.
// Privileges: None.
//   Notes: postgres does not have a "show databases"
//          mysql has a "SHOW DATABASES" permission, but we have no system-level permissions.
func (p *planner) ShowDatabases(n *parser.ShowDatabases) (planNode, error) {
	// TODO(pmattis): This could be implemented as:
	//
	//   SELECT id FROM system.namespace WHERE parentID = 0

	columns := ResultColumns{{Name: "Database", Typ: parser.TypeString}}

	return &delayedNode{
		p:       p,
		name:    "SHOW DATABASES",
		columns: columns,
		constructor: func(p *planner) (planNode, error) {
			prefix := sqlbase.MakeNameMetadataKey(keys.RootNamespaceID, "")
			sr, err := p.txn.Scan(prefix, prefix.PrefixEnd(), 0)
			if err != nil {
				return nil, err
			}
			v := p.newContainerValuesNode(columns, 0)
			for _, db := range p.session.virtualSchemas.orderedNames {
				if err := v.rows.AddRow(parser.DTuple{parser.NewDString(db)}); err != nil {
					v.rows.Close()
					return nil, err
				}
			}
			for _, row := range sr {
				_, name, err := encoding.DecodeUnsafeStringAscending(
					bytes.TrimPrefix(row.Key, prefix), nil)
				if err != nil {
					v.rows.Close()
					return nil, err
				}
				if err := v.rows.AddRow(parser.DTuple{parser.NewDString(name)}); err != nil {
					v.rows.Close()
					return nil, err
				}
			}
			return v, nil
		},
	}, nil
}
Пример #3
0
// DecodeTableKey decodes a table key/value.
func DecodeTableKey(
	a *DatumAlloc, valType parser.Type, key []byte, dir encoding.Direction,
) (parser.Datum, []byte, error) {
	if (dir != encoding.Ascending) && (dir != encoding.Descending) {
		return nil, nil, errors.Errorf("invalid direction: %d", dir)
	}
	var isNull bool
	if key, isNull = encoding.DecodeIfNull(key); isNull {
		return parser.DNull, key, nil
	}
	var rkey []byte
	var err error
	switch valType {
	case parser.TypeBool:
		var i int64
		if dir == encoding.Ascending {
			rkey, i, err = encoding.DecodeVarintAscending(key)
		} else {
			rkey, i, err = encoding.DecodeVarintDescending(key)
		}
		// No need to chunk allocate DBool as MakeDBool returns either
		// parser.DBoolTrue or parser.DBoolFalse.
		return parser.MakeDBool(parser.DBool(i != 0)), rkey, err
	case parser.TypeInt:
		var i int64
		if dir == encoding.Ascending {
			rkey, i, err = encoding.DecodeVarintAscending(key)
		} else {
			rkey, i, err = encoding.DecodeVarintDescending(key)
		}
		return a.NewDInt(parser.DInt(i)), rkey, err
	case parser.TypeFloat:
		var f float64
		if dir == encoding.Ascending {
			rkey, f, err = encoding.DecodeFloatAscending(key)
		} else {
			rkey, f, err = encoding.DecodeFloatDescending(key)
		}
		return a.NewDFloat(parser.DFloat(f)), rkey, err
	case parser.TypeDecimal:
		var d *inf.Dec
		if dir == encoding.Ascending {
			rkey, d, err = encoding.DecodeDecimalAscending(key, nil)
		} else {
			rkey, d, err = encoding.DecodeDecimalDescending(key, nil)
		}
		dd := a.NewDDecimal(parser.DDecimal{})
		dd.Set(d)
		return dd, rkey, err
	case parser.TypeString:
		var r string
		if dir == encoding.Ascending {
			rkey, r, err = encoding.DecodeUnsafeStringAscending(key, nil)
		} else {
			rkey, r, err = encoding.DecodeUnsafeStringDescending(key, nil)
		}
		return a.NewDString(parser.DString(r)), rkey, err
	case parser.TypeBytes:
		var r []byte
		if dir == encoding.Ascending {
			rkey, r, err = encoding.DecodeBytesAscending(key, nil)
		} else {
			rkey, r, err = encoding.DecodeBytesDescending(key, nil)
		}
		return a.NewDBytes(parser.DBytes(r)), rkey, err
	case parser.TypeDate:
		var t int64
		if dir == encoding.Ascending {
			rkey, t, err = encoding.DecodeVarintAscending(key)
		} else {
			rkey, t, err = encoding.DecodeVarintDescending(key)
		}
		return a.NewDDate(parser.DDate(t)), rkey, err
	case parser.TypeTimestamp:
		var t time.Time
		if dir == encoding.Ascending {
			rkey, t, err = encoding.DecodeTimeAscending(key)
		} else {
			rkey, t, err = encoding.DecodeTimeDescending(key)
		}
		return a.NewDTimestamp(parser.DTimestamp{Time: t}), rkey, err
	case parser.TypeTimestampTZ:
		var t time.Time
		if dir == encoding.Ascending {
			rkey, t, err = encoding.DecodeTimeAscending(key)
		} else {
			rkey, t, err = encoding.DecodeTimeDescending(key)
		}
		return a.NewDTimestampTZ(parser.DTimestampTZ{Time: t}), rkey, err
	case parser.TypeInterval:
		var d duration.Duration
		if dir == encoding.Ascending {
			rkey, d, err = encoding.DecodeDurationAscending(key)
		} else {
			rkey, d, err = encoding.DecodeDurationDescending(key)
		}
		return a.NewDInterval(parser.DInterval{Duration: d}), rkey, err
	default:
		return nil, nil, errors.Errorf("TODO(pmattis): decoded index key: %s", valType)
	}
}