optimizer

Documentation

Index

• Constants
• Variables
• func InferType(node ast.Node) error
• func Optimize(ctx context.Context, node ast.Node, sb plan.SubQueryBuilder) (plan.Plan, error)
• func Prepare(is infoschema.InfoSchema, ctx context.Context, node ast.Node) error
• func Preprocess(node ast.Node, info infoschema.InfoSchema, ctx context.Context) error
• func ResolveName(node ast.Node, info infoschema.InfoSchema, ctx context.Context) error
• func Validate(node ast.Node, inPrepare bool) error

Constants

const (
	CodeOneColumn           terror.ErrCode = 1
	CodeSameColumns         terror.ErrCode = 2
	CodeMultiWildCard       terror.ErrCode = 3
	CodeUnsupported         terror.ErrCode = 4
	CodeInvalidGroupFuncUse terror.ErrCode = 5
	CodeIllegalReference    terror.ErrCode = 6
)

Optimizer error codes.

Variables

var (
	ErrOneColumn           = terror.ClassOptimizer.New(CodeOneColumn, "Operand should contain 1 column(s)")
	ErrSameColumns         = terror.ClassOptimizer.New(CodeSameColumns, "Operands should contain same columns")
	ErrMultiWildCard       = terror.ClassOptimizer.New(CodeMultiWildCard, "wildcard field exist more than once")
	ErrUnSupported         = terror.ClassOptimizer.New(CodeUnsupported, "unsupported")
	ErrInvalidGroupFuncUse = terror.ClassOptimizer.New(CodeInvalidGroupFuncUse, "Invalid use of group function")
	ErrIllegalReference    = terror.ClassOptimizer.New(CodeIllegalReference, "Illegal reference")
)

Optimizer base errors.

Functions

func InferType

func InferType(node ast.Node) error

InferType infers result type for ast.ExprNode.

func Optimize

func Optimize(ctx context.Context, node ast.Node, sb plan.SubQueryBuilder) (plan.Plan, error)

Optimize does optimization and creates a Plan. The node must be prepared first.

func Prepare

func Prepare(is infoschema.InfoSchema, ctx context.Context, node ast.Node) error

Prepare prepares a raw statement parsed from parser. The statement must be prepared before it can be passed to optimize function. We pass InfoSchema instead of getting from Context in case it is changed after resolving name.

func Preprocess

func Preprocess(node ast.Node, info infoschema.InfoSchema, ctx context.Context) error

Preprocess does preprocess work for optimizer.

func ResolveName

func ResolveName(node ast.Node, info infoschema.InfoSchema, ctx context.Context) error

ResolveName resolves table name and column name. It generates ResultFields for ResultSetNode and resolves ColumnNameExpr to a ResultField.

func Validate

func Validate(node ast.Node, inPrepare bool) error

Validate checkes whether the node is valid.