// 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
}
// 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
}
// 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)
}
}
