util

Documentation

Index

• type AccessPath
  • func (path *AccessPath) SplitCorColAccessCondFromFilters(ctx sessionctx.Context, eqOrInCount int) (access, remained []expression.Expression)

Types

type AccessPath

type AccessPath struct {
	Index          *model.IndexInfo
	FullIdxCols    []*expression.Column
	FullIdxColLens []int
	IdxCols        []*expression.Column
	IdxColLens     []int
	Ranges         []*ranger.Range
	// CountAfterAccess is the row count after we apply range seek and before we use other filter to filter data.
	CountAfterAccess float64
	// CountAfterIndex is the row count after we apply filters on index and before we apply the table filters.
	CountAfterIndex float64
	AccessConds     []expression.Expression
	EqCondCount     int
	EqOrInCondCount int
	IndexFilters    []expression.Expression
	TableFilters    []expression.Expression
	// PartialIndexPaths store all index access paths.
	// If there are extra filters, store them in TableFilters.
	PartialIndexPaths []*AccessPath

	StoreType kv.StoreType

	IsDNFCond bool

	// IsTablePath indicates whether this path is table path.
	IsTablePath bool
	// Forced means this path is generated by `use/force index()`.
	Forced bool
}

AccessPath indicates the way we access a table: by using single index, or by using multiple indexes, or just by using table scan.

func (*AccessPath) SplitCorColAccessCondFromFilters

func (path *AccessPath) SplitCorColAccessCondFromFilters(ctx sessionctx.Context, eqOrInCount int) (access, remained []expression.Expression)

SplitCorColAccessCondFromFilters move the necessary filter in the form of index_col = corrlated_col to access conditions.